diff mbox

[v2] Ext support for UEFI

Message ID 1372229387-19900-1-git-send-email-rony.nandy@linaro.org
State New
Headers show

Commit Message

Rony Nandy June 26, 2013, 6:49 a.m. UTC
Ext4,ext3 and ext2 support for UEFI

This patch is created with code ported from https://github.com/falstaff84/rEFInd/blob/master/filesystems/
into the Linaro UEFI tree.

UEFI boot manager will be able to detect ext partitions after this patch is applied and will be able to boot
from uImages store in the ext partitions.

All the licence and attributions in the original files remain the same.

Signed-off-by: Aditya Pratap Sharma <aditya.ps@samsung.com>
Signed-off-by: Rony Nandy <rony.nandy@linaro.org>
---
 ExtPkg/ExtPkg.dec                                  |    5 +
 ExtPkg/ExtPkg.dsc                                  |   67 ++
 ExtPkg/ExtPkgDxe/Ext.h                             |   43 +
 ExtPkg/ExtPkgDxe/Ext.inf                           |   57 +
 ExtPkg/ExtPkgDxe/fsw_core.c                        |  932 ++++++++++++++++
 ExtPkg/ExtPkgDxe/fsw_core.h                        |  570 ++++++++++
 ExtPkg/ExtPkgDxe/fsw_efi.c                         | 1167 ++++++++++++++++++++
 ExtPkg/ExtPkgDxe/fsw_efi.h                         |  132 +++
 ExtPkg/ExtPkgDxe/fsw_efi_base.h                    |   89 ++
 ExtPkg/ExtPkgDxe/fsw_efi_lib.c                     |  159 +++
 ExtPkg/ExtPkgDxe/fsw_ext2.c                        |  553 ++++++++++
 ExtPkg/ExtPkgDxe/fsw_ext2.h                        |   65 ++
 ExtPkg/ExtPkgDxe/fsw_ext2_disk.h                   |  356 ++++++
 ExtPkg/ExtPkgDxe/fsw_ext4.c                        |  731 ++++++++++++
 ExtPkg/ExtPkgDxe/fsw_ext4.h                        |   66 ++
 ExtPkg/ExtPkgDxe/fsw_ext4_disk.h                   |  500 +++++++++
 ExtPkg/ExtPkgDxe/fsw_lib.c                         |  336 ++++++
 ExtPkg/ExtPkgDxe/fsw_strfunc.h                     |  472 ++++++++
 .../ArndaleBoardPkg/arndale-Exynos5250.dsc         |    1 +
 .../ArndaleBoardPkg/arndale-Exynos5250.fdf         |    1 +
 20 files changed, 6302 insertions(+)
 create mode 100644 ExtPkg/ExtPkg.dec
 create mode 100644 ExtPkg/ExtPkg.dsc
 create mode 100644 ExtPkg/ExtPkgDxe/Ext.h
 create mode 100644 ExtPkg/ExtPkgDxe/Ext.inf
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_core.c
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_core.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_efi.c
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_efi.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_efi_base.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_efi_lib.c
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_ext2.c
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_ext2.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_ext2_disk.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_ext4.c
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_ext4.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_ext4_disk.h
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_lib.c
 create mode 100644 ExtPkg/ExtPkgDxe/fsw_strfunc.h
diff mbox

Patch

diff --git a/ExtPkg/ExtPkg.dec b/ExtPkg/ExtPkg.dec
new file mode 100644
index 0000000..2a7935a
--- /dev/null
+++ b/ExtPkg/ExtPkg.dec
@@ -0,0 +1,5 @@ 
+[Defines]
+  DEC_SPECIFICATION              = 0x00010005
+  PACKAGE_NAME                   = Ext2Pkg
+  PACKAGE_GUID                   = 8EA68A2C-99CB-4332-85C6-DD5864EAA674
+  PACKAGE_VERSION                = 0.1
diff --git a/ExtPkg/ExtPkg.dsc b/ExtPkg/ExtPkg.dsc
new file mode 100644
index 0000000..28e16a5
--- /dev/null
+++ b/ExtPkg/ExtPkg.dsc
@@ -0,0 +1,67 @@ 
+[Defines]
+  PLATFORM_NAME                  = Ext2
+  PLATFORM_GUID                  = 25b55dbc-9d0b-4a32-80da-46e1273d623c
+  PLATFORM_VERSION               = 0.1
+  DSC_SPECIFICATION              = 0x00010005
+  SUPPORTED_ARCHITECTURES        = ARM
+  OUTPUT_DIRECTORY               = Build/Ext2
+  BUILD_TARGETS                  = DEBUG|RELEASE
+  SKUID_IDENTIFIER               = DEFAULT
+
+[BuildOptions]
+  GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG
+  INTEL:RELEASE_*_*_CC_FLAGS           = /D MDEPKG_NDEBUG
+  MSFT:RELEASE_*_*_CC_FLAGS            = /D MDEPKG_NDEBUG
+  RVCT:RELEASE_*_*_CC_FLAGS            = -DMDEPKG_NDEBUG
+
+[LibraryClasses]
+  #
+  # Entry Point Libraries
+  #
+  UefiDriverEntryPoint|MdePkg/Library/UefiDriverEntryPoint/UefiDriverEntryPoint.inf
+  #
+  # Common Libraries
+  #
+  BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
+  BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
+  UefiLib|MdePkg/Library/UefiLib/UefiLib.inf
+  PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
+  PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
+  MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
+  UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
+  UefiRuntimeServicesTableLib|MdePkg/Library/UefiRuntimeServicesTableLib/UefiRuntimeServicesTableLib.inf
+  DebugLib|MdePkg/Library/BaseDebugLibNull/BaseDebugLibNull.inf
+  DebugPrintErrorLevelLib|MdePkg/Library/BaseDebugPrintErrorLevelLib/BaseDebugPrintErrorLevelLib.inf  
+  DevicePathLib|MdePkg/Library/UefiDevicePathLib/UefiDevicePathLib.inf
+
+[LibraryClasses.common.PEIM]
+  PeimEntryPoint|MdePkg/Library/PeimEntryPoint/PeimEntryPoint.inf
+  PeiServicesLib|MdePkg/Library/PeiServicesLib/PeiServicesLib.inf
+  PeiServicesTablePointerLib|MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf
+  HobLib|MdePkg/Library/PeiHobLib/PeiHobLib.inf
+  MemoryAllocationLib|MdePkg/Library/PeiMemoryAllocationLib/PeiMemoryAllocationLib.inf
+
+[LibraryClasses.ARM]
+  NULL|ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
+
+###################################################################################################
+#
+# Components Section - list of the modules and components that will be processed by compilation
+#                      tools and the EDK II tools to generate PE32/PE32+/Coff image files.
+#
+# Note: The EDK II DSC file is not used to specify how compiled binary images get placed
+#       into firmware volume images. This section is just a list of modules to compile from
+#       source into UEFI-compliant binaries.
+#       It is the FDF file that contains information on combining binary files into firmware
+#       volume images, whose concept is beyond UEFI and is described in PI specification.
+#       Binary modules do not need to be listed in this section, as they should be
+#       specified in the FDF file. For example: Shell binary (Shell_Full.efi), EXT2 binary (Ext2.efi),
+#       Logo (Logo.bmp), and etc.
+#       There may also be modules listed in this section that are not required in the FDF file,
+#       When a module listed here is excluded from FDF file, then UEFI-compliant binary will be
+#       generated for it, but the binary will not be put into any firmware volume.
+#
+###################################################################################################
+
+[Components]
+  Ext2Pkg/Ext2PkgDxe/Ext2.inf
diff --git a/ExtPkg/ExtPkgDxe/Ext.h b/ExtPkg/ExtPkgDxe/Ext.h
new file mode 100644
index 0000000..76c6e8c
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/Ext.h
@@ -0,0 +1,43 @@ 
+#ifndef _EXT2_H_
+#define _EXT2_H_
+
+#include <Uefi.h>
+
+#include <Guid/FileInfo.h>
+#include <Guid/FileSystemInfo.h>
+#include <Guid/FileSystemVolumeLabelInfo.h>
+#include <Protocol/BlockIo.h>
+#include <Protocol/DiskIo.h>
+#include <Protocol/SimpleFileSystem.h>
+#include <Protocol/UnicodeCollation.h>
+
+#include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
+#include <Library/UefiLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+//
+#define IS_LEAP_YEAR(a)                   (((a) % 4 == 0) && (((a) % 100 != 0) || ((a) % 400 == 0)))
+
+#define EFI_PATH_STRING_LENGTH  260
+#define EFI_FILE_STRING_LENGTH  255
+
+#define CACHE_ENABLED(a)  ((a) >= 2)
+#define RAW_ACCESS(a)     ((IO_MODE)((a) & 0x1))
+#define CACHE_TYPE(a)     ((CACHE_DATA_TYPE)((a) >> 2))
+
+//
+// Global Variables
+//
+extern EFI_DRIVER_BINDING_PROTOCOL     gExtDriverBinding;
+extern EFI_COMPONENT_NAME_PROTOCOL     gExtComponentName;
+extern EFI_COMPONENT_NAME2_PROTOCOL    gExtComponentName2;
+extern EFI_LOCK                        ExtFsLock;
+extern EFI_FILE_PROTOCOL               ExtFileInterface;
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/Ext.inf b/ExtPkg/ExtPkgDxe/Ext.inf
new file mode 100644
index 0000000..3bf61bb
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/Ext.inf
@@ -0,0 +1,57 @@ 
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = Ext2
+  FILE_GUID                      = 961578FE-B6B7-44c3-AF35-6BC705CD2B2F
+  MODULE_TYPE                    = UEFI_DRIVER
+  VERSION_STRING                 = 1.0
+
+  ENTRY_POINT                    = fsw_efi_main
+  UNLOAD_IMAGE                   = ExtUnload
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = ARM
+#
+#  DRIVER_BINDING                =  gExt2DriverBinding
+#  COMPONENT_NAME                =  gExt2ComponentName
+#  COMPONENT_NAME2               =  gExt2ComponentName2
+#
+
+[Sources]
+	fsw_core.c
+	fsw_ext2.c
+	fsw_ext4.c
+	fsw_efi.c
+	fsw_efi_lib.c
+	fsw_lib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  UefiRuntimeServicesTableLib
+  UefiBootServicesTableLib
+  MemoryAllocationLib
+  BaseMemoryLib
+  BaseLib
+  UefiLib
+  UefiDriverEntryPoint
+  DebugLib
+  PcdLib
+
+[Guids]
+  gEfiFileInfoGuid
+  gEfiFileSystemInfoGuid
+  gEfiFileSystemVolumeLabelInfoIdGuid
+
+[Protocols]
+  gEfiDiskIoProtocolGuid
+  gEfiBlockIoProtocolGuid
+  gEfiSimpleFileSystemProtocolGuid
+  gEfiUnicodeCollationProtocolGuid
+  gEfiUnicodeCollation2ProtocolGuid
+
+[Pcd]
+  gEfiMdePkgTokenSpaceGuid.PcdUefiVariableDefaultLang
+  gEfiMdePkgTokenSpaceGuid.PcdUefiVariableDefaultPlatformLang
diff --git a/ExtPkg/ExtPkgDxe/fsw_core.c b/ExtPkg/ExtPkgDxe/fsw_core.c
new file mode 100644
index 0000000..85f606b
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_core.c
@@ -0,0 +1,932 @@ 
+/* $Id: fsw_core.c 29125 2010-05-06 09:43:05Z vboxsync $ */
+/** @file
+ * fsw_core.c - Core file system wrapper abstraction layer code.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fsw_core.h"
+
+
+// functions
+
+static void fsw_blockcache_free(struct fsw_volume *vol);
+
+#define MAX_CACHE_LEVEL (5)
+
+
+/**
+ * Mount a volume with a given file system driver. This function is called by the
+ * host driver to make a volume accessible. The file system driver to use is specified
+ * by a pointer to its dispatch table. The file system driver will look at the
+ * data on the volume to determine if it can read the format. If the volume is found
+ * unsuitable, FSW_UNSUPPORTED is returned.
+ *
+ * If this function returns FSW_SUCCESS, *vol_out points at a valid volume data
+ * structure. The caller must release it later by calling fsw_unmount.
+ *
+ * If this function returns an error status, the caller only needs to clean up its
+ * own buffers that may have been allocated through the read_block interface.
+ */
+
+fsw_status_t fsw_mount(void *host_data,
+                       struct fsw_host_table *host_table,
+                       struct fsw_fstype_table *fstype_table,
+                       struct fsw_volume **vol_out)
+{
+    fsw_status_t    status;
+    struct fsw_volume *vol;
+
+    // allocate memory for the structure
+    status = fsw_alloc_zero(fstype_table->volume_struct_size, (void **)&vol);
+    if (status)
+        return status;
+
+    // initialize fields
+    vol->phys_blocksize = 512;
+    vol->log_blocksize  = 512;
+    vol->label.type     = FSW_STRING_TYPE_EMPTY;
+    vol->host_data      = host_data;
+    vol->host_table     = host_table;
+    vol->fstype_table   = fstype_table;
+    vol->host_string_type = host_table->native_string_type;
+
+    // let the fs driver mount the file system
+    status = vol->fstype_table->volume_mount(vol);
+    if (status)
+        goto errorexit;
+
+    // TODO: anything else?
+
+    *vol_out = vol;
+    return FSW_SUCCESS;
+
+errorexit:
+    fsw_unmount(vol);
+    return status;
+}
+
+/**
+ * Unmount a volume by releasing all memory associated with it. This function is
+ * called by the host driver when a volume is no longer needed. It is also called
+ * by the core after a failed mount to clean up any allocated memory.
+ *
+ * Note that all dnodes must have been released before calling this function.
+ */
+
+void fsw_unmount(struct fsw_volume *vol)
+{
+    if (vol->root)
+        fsw_dnode_release(vol->root);
+    // TODO: check that no other dnodes are still around
+
+    vol->fstype_table->volume_free(vol);
+
+    fsw_blockcache_free(vol);
+    fsw_strfree(&vol->label);
+    fsw_free(vol);
+}
+
+/**
+ * Get in-depth information on the volume. This function can be called by the host
+ * driver to get additional information on the volume.
+ */
+
+fsw_status_t fsw_volume_stat(struct fsw_volume *vol, struct fsw_volume_stat *sb)
+{
+    return vol->fstype_table->volume_stat(vol, sb);
+}
+
+/**
+ * Set the physical and logical block sizes of the volume. This functions is called by
+ * the file system driver to announce the block sizes it wants to use for accessing
+ * the disk (physical) and for addressing file contents (logical).
+ * Usually both sizes will be the same but there may be file systems that need to access
+ * metadata at a smaller block size than the allocation unit for files.
+ *
+ * Calling this function causes the block cache to be dropped. All pointers returned
+ * from fsw_block_get become invalid. This function should only be called while
+ * mounting the file system, not as a part of file access operations.
+ *
+ * Both sizes are measured in bytes, must be powers of 2, and must not be smaller
+ * than 512 bytes. The logical block size cannot be smaller than the physical block size.
+ */
+
+void fsw_set_blocksize(struct fsw_volume *vol, fsw_u32 phys_blocksize, fsw_u32 log_blocksize)
+{
+    // TODO: Check the sizes. Both must be powers of 2. log_blocksize must not be smaller than
+    //  phys_blocksize.
+
+    // drop core block cache if present
+    fsw_blockcache_free(vol);
+
+    // signal host driver to drop caches etc.
+    vol->host_table->change_blocksize(vol,
+                                      vol->phys_blocksize, vol->log_blocksize,
+                                      phys_blocksize, log_blocksize);
+
+    vol->phys_blocksize = phys_blocksize;
+    vol->log_blocksize = log_blocksize;
+}
+
+/**
+ * Get a block of data from the disk. This function is called by the file system driver
+ * or by core functions. It calls through to the host driver's device access routine.
+ * Given a physical block number, it reads the block into memory (or fetches it from the
+ * block cache) and returns the address of the memory buffer. The caller should provide
+ * an indication of how important the block is in the cache_level parameter. Blocks with
+ * a low level are purged first. Some suggestions for cache levels:
+ *
+ *  - 0: File data
+ *  - 1: Directory data, symlink data
+ *  - 2: File system metadata
+ *  - 3..5: File system metadata with a high rate of access
+ *
+ * If this function returns successfully, the returned data pointer is valid until the
+ * caller calls fsw_block_release.
+ */
+
+fsw_status_t fsw_block_get(struct VOLSTRUCTNAME *vol, fsw_u32 phys_bno, fsw_u32 cache_level, void **buffer_out)
+{
+    fsw_status_t    status;
+    fsw_u32         i, discard_level, new_bcache_size;
+    struct fsw_blockcache *new_bcache;
+
+    // TODO: allow the host driver to do its own caching; just call through if
+    //  the appropriate function pointers are set
+
+    if (cache_level > MAX_CACHE_LEVEL)
+        cache_level = MAX_CACHE_LEVEL;
+
+    // check block cache
+    for (i = 0; i < vol->bcache_size; i++) {
+        if (vol->bcache[i].phys_bno == phys_bno) {
+            // cache hit!
+            if (vol->bcache[i].cache_level < cache_level)
+                vol->bcache[i].cache_level = cache_level;  // promote the entry
+            vol->bcache[i].refcount++;
+            *buffer_out = vol->bcache[i].data;
+            return FSW_SUCCESS;
+        }
+    }
+
+    // find a free entry in the cache table
+    for (i = 0; i < vol->bcache_size; i++) {
+        if (vol->bcache[i].phys_bno == (fsw_u32)FSW_INVALID_BNO)
+            break;
+    }
+    if (i >= vol->bcache_size) {
+        for (discard_level = 0; discard_level <= MAX_CACHE_LEVEL; discard_level++) {
+            for (i = 0; i < vol->bcache_size; i++) {
+                if (vol->bcache[i].refcount == 0 && vol->bcache[i].cache_level <= discard_level)
+                    break;
+            }
+            if (i < vol->bcache_size)
+                break;
+        }
+    }
+    if (i >= vol->bcache_size) {
+        // enlarge / create the cache
+        if (vol->bcache_size < 16)
+            new_bcache_size = 16;
+        else
+            new_bcache_size = vol->bcache_size << 1;
+        status = fsw_alloc(new_bcache_size * sizeof(struct fsw_blockcache), &new_bcache);
+        if (status)
+            return status;
+        if (vol->bcache_size > 0)
+            fsw_memcpy(new_bcache, vol->bcache, vol->bcache_size * sizeof(struct fsw_blockcache));
+        for (i = vol->bcache_size; i < new_bcache_size; i++) {
+            new_bcache[i].refcount = 0;
+            new_bcache[i].cache_level = 0;
+            new_bcache[i].phys_bno = (fsw_u32)FSW_INVALID_BNO;
+            new_bcache[i].data = NULL;
+        }
+        i = vol->bcache_size;
+
+        // switch caches
+        if (vol->bcache != NULL)
+            fsw_free(vol->bcache);
+        vol->bcache = new_bcache;
+        vol->bcache_size = new_bcache_size;
+    }
+    vol->bcache[i].phys_bno = (fsw_u32)FSW_INVALID_BNO;
+
+    // read the data
+    if (vol->bcache[i].data == NULL) {
+        status = fsw_alloc(vol->phys_blocksize, &vol->bcache[i].data);
+        if (status)
+            return status;
+    }
+    status = vol->host_table->read_block(vol, phys_bno, vol->bcache[i].data);
+    if (status)
+        return status;
+
+    vol->bcache[i].phys_bno = phys_bno;
+    vol->bcache[i].cache_level = cache_level;
+    vol->bcache[i].refcount = 1;
+    *buffer_out = vol->bcache[i].data;
+    return FSW_SUCCESS;
+}
+
+/**
+ * Releases a disk block. This function must be called to release disk blocks returned
+ * from fsw_block_get.
+ */
+
+void fsw_block_release(struct VOLSTRUCTNAME *vol, fsw_u32 phys_bno, void *buffer)
+{
+    fsw_u32 i;
+
+    // TODO: allow the host driver to do its own caching; just call through if
+    //  the appropriate function pointers are set
+
+    // update block cache
+    for (i = 0; i < vol->bcache_size; i++) {
+        if (vol->bcache[i].phys_bno == phys_bno && vol->bcache[i].refcount > 0)
+            vol->bcache[i].refcount--;
+    }
+}
+
+/**
+ * Release the block cache. Called internally when changing block sizes and when
+ * unmounting the volume. It frees all data occupied by the generic block cache.
+ */
+
+static void fsw_blockcache_free(struct fsw_volume *vol)
+{
+    fsw_u32 i;
+
+    for (i = 0; i < vol->bcache_size; i++) {
+        if (vol->bcache[i].data != NULL)
+            fsw_free(vol->bcache[i].data);
+    }
+    if (vol->bcache != NULL) {
+        fsw_free(vol->bcache);
+        vol->bcache = NULL;
+    }
+    vol->bcache_size = 0;
+}
+
+/**
+ * Add a new dnode to the list of known dnodes. This internal function is used when a
+ * dnode is created to add it to the dnode list that is used to search for existing
+ * dnodes by id.
+ */
+
+static void fsw_dnode_register(struct fsw_volume *vol, struct fsw_dnode *dno)
+{
+    dno->next = vol->dnode_head;
+    if (vol->dnode_head != NULL)
+        vol->dnode_head->prev = dno;
+    dno->prev = NULL;
+    vol->dnode_head = dno;
+}
+
+/**
+ * Create a dnode representing the root directory. This function is called by the file system
+ * driver while mounting the file system. The root directory is special because it has no parent
+ * dnode, its name is defined to be empty, and its type is also fixed. Otherwise, this functions
+ * behaves in the same way as fsw_dnode_create.
+ */
+
+fsw_status_t fsw_dnode_create_root(struct fsw_volume *vol, fsw_u32 dnode_id, struct fsw_dnode **dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_dnode *dno;
+
+    // allocate memory for the structure
+    status = fsw_alloc_zero(vol->fstype_table->dnode_struct_size, (void **)&dno);
+    if (status)
+        return status;
+
+    // fill the structure
+    dno->vol = vol;
+    dno->parent = NULL;
+    dno->dnode_id = dnode_id;
+    dno->type = FSW_DNODE_TYPE_DIR;
+    dno->refcount = 1;
+    dno->name.type = FSW_STRING_TYPE_EMPTY;
+    // TODO: instead, call a function to create an empty string in the native string type
+
+    fsw_dnode_register(vol, dno);
+
+    *dno_out = dno;
+    return FSW_SUCCESS;
+}
+
+/**
+ * Create a new dnode representing a file system object. This function is called by
+ * the file system driver in response to directory lookup or read requests. Note that
+ * if there already is a dnode with the given dnode_id on record, then no new object
+ * is created. Instead, the existing dnode is returned and its reference count
+ * increased. All other parameters are ignored in this case.
+ *
+ * The type passed into this function may be FSW_DNODE_TYPE_UNKNOWN. It is sufficient
+ * to fill the type field during the dnode_fill call.
+ *
+ * The name parameter must describe a string with the object's name. A copy will be
+ * stored in the dnode structure for future reference. The name will not be used to
+ * shortcut directory lookups, but may be used to reconstruct paths.
+ *
+ * If the function returns successfully, *dno_out contains a pointer to the dnode
+ * that must be released by the caller with fsw_dnode_release.
+ */
+
+fsw_status_t fsw_dnode_create(struct fsw_dnode *parent_dno, fsw_u32 dnode_id, int type,
+                              struct fsw_string *name, struct fsw_dnode **dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_volume *vol = parent_dno->vol;
+    struct fsw_dnode *dno;
+
+    // check if we already have a dnode with the same id
+    for (dno = vol->dnode_head; dno; dno = dno->next) {
+        if (dno->dnode_id == dnode_id) {
+            fsw_dnode_retain(dno);
+            *dno_out = dno;
+            return FSW_SUCCESS;
+        }
+    }
+
+    // allocate memory for the structure
+    status = fsw_alloc_zero(vol->fstype_table->dnode_struct_size, (void **)&dno);
+    if (status)
+        return status;
+
+    // fill the structure
+    dno->vol = vol;
+    dno->parent = parent_dno;
+    fsw_dnode_retain(dno->parent);
+    dno->dnode_id = dnode_id;
+    dno->type = type;
+    dno->refcount = 1;
+    status = fsw_strdup_coerce(&dno->name, vol->host_table->native_string_type, name);
+    if (status) {
+        fsw_free(dno);
+        return status;
+    }
+
+    fsw_dnode_register(vol, dno);
+
+    *dno_out = dno;
+    return FSW_SUCCESS;
+}
+
+/**
+ * Increases the reference count of a dnode. This must be balanced with
+ * fsw_dnode_release calls. Note that some dnode functions return a retained
+ * dnode pointer to their caller.
+ */
+
+void fsw_dnode_retain(struct fsw_dnode *dno)
+{
+    dno->refcount++;
+}
+
+/**
+ * Release a dnode pointer, deallocating it if this was the last reference.
+ * This function decrements the reference counter of the dnode. If the counter
+ * reaches zero, the dnode is freed. Since the parent dnode is released
+ * during that process, this function may cause it to be freed, too.
+ */
+
+void fsw_dnode_release(struct fsw_dnode *dno)
+{
+    struct fsw_volume *vol = dno->vol;
+    struct fsw_dnode *parent_dno;
+
+    dno->refcount--;
+
+    if (dno->refcount == 0) {
+        parent_dno = dno->parent;
+
+        // de-register from volume's list
+        if (dno->next)
+            dno->next->prev = dno->prev;
+        if (dno->prev)
+            dno->prev->next = dno->next;
+        if (vol->dnode_head == dno)
+            vol->dnode_head = dno->next;
+
+        // run fstype-specific cleanup
+        vol->fstype_table->dnode_free(vol, dno);
+
+        fsw_strfree(&dno->name);
+        fsw_free(dno);
+
+        // release our pointer to the parent, possibly deallocating it, too
+        if (parent_dno)
+            fsw_dnode_release(parent_dno);
+    }
+}
+
+/**
+ * Get full information about a dnode from disk. This function is called by the host
+ * driver as well as by the core functions. Some file systems defer reading full
+ * information on a dnode until it is actually needed (i.e. separation between
+ * directory and inode information). This function makes sure that all information
+ * is available in the dnode structure. The following fields may not have a correct
+ * value until fsw_dnode_fill has been called:
+ *
+ * type, size
+ */
+
+fsw_status_t fsw_dnode_fill(struct fsw_dnode *dno)
+{
+    // TODO: check a flag right here, call fstype's dnode_fill only once per dnode
+
+    return dno->vol->fstype_table->dnode_fill(dno->vol, dno);
+}
+
+/**
+ * Get extended information about a dnode. This function can be called by the host
+ * driver to get a full compliment of information about a dnode in addition to the
+ * fields of the fsw_dnode structure itself.
+ *
+ * Some data requires host-specific conversion to be useful (i.e. timestamps) and
+ * will be passed to callback functions instead of being written into the structure.
+ * These callbacks must be filled in by the caller.
+ */
+
+fsw_status_t fsw_dnode_stat(struct fsw_dnode *dno, struct fsw_dnode_stat *sb)
+{
+    fsw_status_t    status;
+
+    status = fsw_dnode_fill(dno);
+    if (status)
+        return status;
+
+    sb->used_bytes = 0;
+    status = dno->vol->fstype_table->dnode_stat(dno->vol, dno, sb);
+    if (!status && !sb->used_bytes)
+        sb->used_bytes = (dno->size + dno->vol->log_blocksize - 1)/(dno->vol->log_blocksize);
+    return status;
+}
+
+/**
+ * Lookup a directory entry by name. This function is called by the host driver.
+ * Given a directory dnode and a file name, it looks up the named entry in the
+ * directory.
+ *
+ * If the dnode is not a directory, the call will fail. The caller is responsible for
+ * resolving symbolic links before calling this function.
+ *
+ * If the function returns FSW_SUCCESS, *child_dno_out points to the requested directory
+ * entry. The caller must call fsw_dnode_release on it.
+ */
+
+fsw_status_t fsw_dnode_lookup(struct fsw_dnode *dno,
+                              struct fsw_string *lookup_name, struct fsw_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+
+    status = fsw_dnode_fill(dno);
+    if (status)
+        return status;
+    if (dno->type != FSW_DNODE_TYPE_DIR)
+        return FSW_UNSUPPORTED;
+
+    return dno->vol->fstype_table->dir_lookup(dno->vol, dno, lookup_name, child_dno_out);
+}
+
+/**
+ * Find a file system object by path. This function is called by the host driver.
+ * Given a directory dnode and a relative or absolute path, it walks the directory
+ * tree until it finds the target dnode. If an intermediate node turns out to be
+ * a symlink, it is resolved automatically. If the target node is a symlink, it
+ * is not resolved.
+ *
+ * If the function returns FSW_SUCCESS, *child_dno_out points to the requested directory
+ * entry. The caller must call fsw_dnode_release on it.
+ */
+
+fsw_status_t fsw_dnode_lookup_path(struct fsw_dnode *dno,
+                                   struct fsw_string *lookup_path, char separator,
+                                   struct fsw_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_volume *vol = dno->vol;
+    struct fsw_dnode *child_dno = NULL;
+    struct fsw_string lookup_name;
+    struct fsw_string remaining_path;
+    int             root_if_empty;
+
+    remaining_path = *lookup_path;
+    fsw_dnode_retain(dno);
+
+    // loop over the path
+    for (root_if_empty = 1; fsw_strlen(&remaining_path) > 0; root_if_empty = 0) {
+        // parse next path component
+        fsw_strsplit(&lookup_name, &remaining_path, separator);
+
+        FSW_MSG_DEBUG((FSW_MSGSTR("fsw_dnode_lookup_path: split into %d '%s' and %d '%s'\n"),
+                       lookup_name.len, lookup_name.data,
+                       remaining_path.len, remaining_path.data));
+
+        if (fsw_strlen(&lookup_name) == 0) {        // empty path component
+            if (root_if_empty)
+                child_dno = vol->root;
+            else
+                child_dno = dno;
+            fsw_dnode_retain(child_dno);
+
+        } else {
+            // do an actual directory lookup
+
+            // ensure we have full information
+            status = fsw_dnode_fill(dno);
+            if (status)
+                goto errorexit;
+
+            // resolve symlink if necessary
+            if (dno->type == FSW_DNODE_TYPE_SYMLINK) {
+                status = fsw_dnode_resolve(dno, &child_dno);
+                if (status)
+                    goto errorexit;
+
+                // symlink target becomes the new dno
+                fsw_dnode_release(dno);
+                dno = child_dno;   // is already retained
+                child_dno = NULL;
+
+                // ensure we have full information
+                status = fsw_dnode_fill(dno);
+                if (status)
+                    goto errorexit;
+            }
+
+            // make sure we operate on a directory
+            if (dno->type != FSW_DNODE_TYPE_DIR) {
+                return FSW_UNSUPPORTED;
+                goto errorexit;
+            }
+
+            // check special paths
+            if (fsw_streq_cstr(&lookup_name, ".")) {    // self directory
+                child_dno = dno;
+                fsw_dnode_retain(child_dno);
+
+            } else if (fsw_streq_cstr(&lookup_name, "..")) {   // parent directory
+                if (dno->parent == NULL) {
+                    // We cannot go up from the root directory. Caution: Certain apps like the EFI shell
+                    // rely on this behaviour!
+                    status = FSW_NOT_FOUND;
+                    goto errorexit;
+                }
+                child_dno = dno->parent;
+                fsw_dnode_retain(child_dno);
+
+            } else {
+                // do an actual lookup
+                status = vol->fstype_table->dir_lookup(vol, dno, &lookup_name, &child_dno);
+                if (status)
+                    goto errorexit;
+            }
+        }
+
+        // child_dno becomes the new dno
+        fsw_dnode_release(dno);
+        dno = child_dno;   // is already retained
+        child_dno = NULL;
+
+        FSW_MSG_DEBUG((FSW_MSGSTR("fsw_dnode_lookup_path: now at inode %d\n"), dno->dnode_id));
+    }
+
+    *child_dno_out = dno;
+    return FSW_SUCCESS;
+
+errorexit:
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_dnode_lookup_path: leaving with error %d\n"), status));
+    fsw_dnode_release(dno);
+    if (child_dno != NULL)
+        fsw_dnode_release(child_dno);
+    return status;
+}
+
+/**
+ * Get the next directory item in sequential order. This function is called by the
+ * host driver to read the complete contents of a directory in sequential (file system
+ * defined) order. Calling this function returns the next entry. Iteration state is
+ * kept by a shandle on the directory's dnode. The caller must set up the shandle
+ * when starting the iteration.
+ *
+ * When the end of the directory is reached, this function returns FSW_NOT_FOUND.
+ * If the function returns FSW_SUCCESS, *child_dno_out points to the next directory
+ * entry. The caller must call fsw_dnode_release on it.
+ */
+
+fsw_status_t fsw_dnode_dir_read(struct fsw_shandle *shand, struct fsw_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_dnode *dno = shand->dnode;
+    fsw_u64         saved_pos;
+
+    if (dno->type != FSW_DNODE_TYPE_DIR)
+        return FSW_UNSUPPORTED;
+
+    saved_pos = shand->pos;
+    status = dno->vol->fstype_table->dir_read(dno->vol, dno, shand, child_dno_out);
+    if (status)
+        shand->pos = saved_pos;
+    return status;
+}
+
+/**
+ * Read the target path of a symbolic link. This function is called by the host driver
+ * to read the "content" of a symbolic link, that is the relative or absolute path
+ * it points to.
+ *
+ * If the function returns FSW_SUCCESS, the string handle provided by the caller is
+ * filled with a string in the host's preferred encoding. The caller is responsible
+ * for calling fsw_strfree on the string.
+ */
+
+fsw_status_t fsw_dnode_readlink(struct fsw_dnode *dno, struct fsw_string *target_name)
+{
+    fsw_status_t    status;
+
+    status = fsw_dnode_fill(dno);
+    if (status)
+        return status;
+    if (dno->type != FSW_DNODE_TYPE_SYMLINK)
+        return FSW_UNSUPPORTED;
+
+    return dno->vol->fstype_table->readlink(dno->vol, dno, target_name);
+}
+
+/**
+ * Read the target path of a symbolic link by accessing file data. This function can
+ * be called by the file system driver if the file system stores the target path
+ * as normal file data. This function will open an shandle, read the whole content
+ * of the file into a buffer, and build a string from that. Currently the encoding
+ * for the string is fixed as FSW_STRING_TYPE_ISO88591.
+ *
+ * If the function returns FSW_SUCCESS, the string handle provided by the caller is
+ * filled with a string in the host's preferred encoding. The caller is responsible
+ * for calling fsw_strfree on the string.
+ */
+
+fsw_status_t fsw_dnode_readlink_data(struct fsw_dnode *dno, struct fsw_string *link_target)
+{
+    fsw_status_t    status;
+    struct fsw_shandle shand;
+    fsw_u32         buffer_size;
+    char            buffer[FSW_PATH_MAX];
+
+    struct fsw_string s;
+
+    if (dno->size > FSW_PATH_MAX)
+        return FSW_VOLUME_CORRUPTED;
+
+    s.type = FSW_STRING_TYPE_ISO88591;
+    s.size = s.len = (int)dno->size;
+    s.data = buffer;
+
+    // open shandle and read the data
+    status = fsw_shandle_open(dno, &shand);
+    if (status)
+        return status;
+    buffer_size = (fsw_u32)s.size;
+    status = fsw_shandle_read(&shand, &buffer_size, buffer);
+    fsw_shandle_close(&shand);
+    if (status)
+        return status;
+    if ((int)buffer_size < s.size)
+        return FSW_VOLUME_CORRUPTED;
+
+    status = fsw_strdup_coerce(link_target, dno->vol->host_string_type, &s);
+    return status;
+}
+
+/**
+ * Resolve a symbolic link. This function can be called by the host driver to make
+ * sure the a dnode is fully resolved instead of pointing at a symlink. If the dnode
+ * passed in is not a symlink, it is returned unmodified.
+ *
+ * Note that absolute paths will be resolved relative to the root directory of the
+ * volume. If the host is an operating system with its own VFS layer, it should
+ * resolve symlinks on its own.
+ *
+ * If the function returns FSW_SUCCESS, *target_dno_out points at a dnode that is
+ * not a symlink. The caller is responsible for calling fsw_dnode_release on it.
+ */
+
+fsw_status_t fsw_dnode_resolve(struct fsw_dnode *dno, struct fsw_dnode **target_dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_string target_name;
+    struct fsw_dnode *target_dno;
+
+    fsw_dnode_retain(dno);
+
+    while (1) {
+        // get full information
+        status = fsw_dnode_fill(dno);
+        if (status)
+            goto errorexit;
+        if (dno->type != FSW_DNODE_TYPE_SYMLINK) {
+            // found a non-symlink target, return it
+            *target_dno_out = dno;
+            return FSW_SUCCESS;
+        }
+        if (dno->parent == NULL) {    // safety measure, cannot happen in theory
+            status = FSW_NOT_FOUND;
+            goto errorexit;
+        }
+
+        // read the link's target
+        status = fsw_dnode_readlink(dno, &target_name);
+        if (status)
+            goto errorexit;
+
+        // resolve it
+        status = fsw_dnode_lookup_path(dno->parent, &target_name, '/', &target_dno);
+        fsw_strfree(&target_name);
+        if (status)
+            goto errorexit;
+
+        // target_dno becomes the new dno
+        fsw_dnode_release(dno);
+        dno = target_dno;   // is already retained
+    }
+
+errorexit:
+    fsw_dnode_release(dno);
+    return status;
+}
+
+/**
+ * Set up a shandle (storage handle) to access a file's data. This function is called
+ * by the host driver and by the core when they need to access a file's data. It is also
+ * used in accessing the raw data of directories and symlinks if the file system uses
+ * the same mechanisms for storing the data of those items.
+ *
+ * The storage for the fsw_shandle structure is provided by the caller. The dnode and pos
+ * fields may be accessed, pos may also be written to to set the file pointer. The file's
+ * data size is available as shand->dnode->size.
+ *
+ * If this function returns FSW_SUCCESS, the caller must call fsw_shandle_close to release
+ * the dnode reference held by the shandle.
+ */
+
+fsw_status_t fsw_shandle_open(struct fsw_dnode *dno, struct fsw_shandle *shand)
+{
+    fsw_status_t    status;
+    struct fsw_volume *vol = dno->vol;
+
+    // read full dnode information into memory
+    status = vol->fstype_table->dnode_fill(vol, dno);
+    if (status)
+        return status;
+
+    // setup shandle
+    fsw_dnode_retain(dno);
+
+    shand->dnode = dno;
+    shand->pos = 0;
+    shand->extent.type = FSW_EXTENT_TYPE_INVALID;
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Close a shandle after accessing the dnode's data. This function is called by the host
+ * driver or core functions when they are finished with accessing a file's data. It
+ * releases the dnode reference and frees any buffers associated with the shandle itself.
+ * The dnode is only released if this was the last reference using it.
+ */
+
+void fsw_shandle_close(struct fsw_shandle *shand)
+{
+    if (shand->extent.type == FSW_EXTENT_TYPE_BUFFER)
+        fsw_free(shand->extent.buffer);
+    fsw_dnode_release(shand->dnode);
+}
+
+/**
+ * Read data from a shandle (storage handle for a dnode). This function is called by the
+ * host driver or internally when data is read from a file. TODO: more
+ */
+
+fsw_status_t fsw_shandle_read(struct fsw_shandle *shand, fsw_u32 *buffer_size_inout, void *buffer_in)
+{
+    fsw_status_t    status;
+    struct fsw_dnode *dno = shand->dnode;
+    struct fsw_volume *vol = dno->vol;
+    fsw_u8          *buffer, *block_buffer;
+    fsw_u32         buflen, copylen, pos;
+    fsw_u32         log_bno, pos_in_extent, phys_bno, pos_in_physblock;
+    fsw_u32         cache_level;
+
+    if (shand->pos >= dno->size) {   // already at EOF
+        *buffer_size_inout = 0;
+        return FSW_SUCCESS;
+    }
+
+    // initialize vars
+    buffer = buffer_in;
+    buflen = *buffer_size_inout;
+    pos = (fsw_u32)shand->pos;
+    cache_level = (dno->type != FSW_DNODE_TYPE_FILE) ? 1 : 0;
+    // restrict read to file size
+    if (buflen > dno->size - pos)
+        buflen = (fsw_u32)(dno->size - pos);
+
+    while (buflen > 0) {
+        // get extent for the current logical block
+        log_bno = pos / vol->log_blocksize;
+        if (shand->extent.type == FSW_EXTENT_TYPE_INVALID ||
+            log_bno < shand->extent.log_start ||
+            log_bno >= shand->extent.log_start + shand->extent.log_count) {
+
+            if (shand->extent.type == FSW_EXTENT_TYPE_BUFFER)
+                fsw_free(shand->extent.buffer);
+
+            // ask the file system for the proper extent
+            shand->extent.log_start = log_bno;
+            status = vol->fstype_table->get_extent(vol, dno, &shand->extent);
+            if (status) {
+                shand->extent.type = FSW_EXTENT_TYPE_INVALID;
+                return status;
+            }
+        }
+
+        pos_in_extent = pos - shand->extent.log_start * vol->log_blocksize;
+
+        // dispatch by extent type
+        if (shand->extent.type == FSW_EXTENT_TYPE_PHYSBLOCK) {
+            // convert to physical block number and offset
+            phys_bno = shand->extent.phys_start + pos_in_extent / vol->phys_blocksize;
+            pos_in_physblock = pos_in_extent & (vol->phys_blocksize - 1);
+            copylen = vol->phys_blocksize - pos_in_physblock;
+            if (copylen > buflen)
+                copylen = buflen;
+
+            // get one physical block
+            status = fsw_block_get(vol, phys_bno, cache_level, (void **)&block_buffer);
+            if (status)
+                return status;
+
+            // copy data from it
+            fsw_memcpy(buffer, block_buffer + pos_in_physblock, copylen);
+            fsw_block_release(vol, phys_bno, block_buffer);
+
+        } else if (shand->extent.type == FSW_EXTENT_TYPE_BUFFER) {
+            copylen = shand->extent.log_count * vol->log_blocksize - pos_in_extent;
+            if (copylen > buflen)
+                copylen = buflen;
+            fsw_memcpy(buffer, (fsw_u8 *)shand->extent.buffer + pos_in_extent, copylen);
+
+        } else {   // _SPARSE or _INVALID
+            copylen = shand->extent.log_count * vol->log_blocksize - pos_in_extent;
+            if (copylen > buflen)
+                copylen = buflen;
+            fsw_memzero(buffer, copylen);
+
+        }
+
+        buffer += copylen;
+        buflen -= copylen;
+        pos    += copylen;
+    }
+
+    *buffer_size_inout = (fsw_u32)(pos - shand->pos);
+    shand->pos = pos;
+
+    return FSW_SUCCESS;
+}
+
+// EOF
diff --git a/ExtPkg/ExtPkgDxe/fsw_core.h b/ExtPkg/ExtPkgDxe/fsw_core.h
new file mode 100644
index 0000000..b32808e
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_core.h
@@ -0,0 +1,570 @@ 
+/* $Id: fsw_core.h 33540 2010-10-28 09:27:05Z vboxsync $ */
+/** @file
+ * fsw_core.h - Core file system wrapper abstraction layer header.
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ * Portions Copyright (c) The Regents of the University of California.
+ * Portions Copyright (c) UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _FSW_CORE_H_
+#define _FSW_CORE_H_
+
+#include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
+#include <Library/UefiLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+#include "fsw_efi_base.h"
+
+#ifndef FSW_DEBUG_LEVEL
+/**
+ * Global debugging level. Can be set locally for the scope of a single
+ * file by defining the macro before fsw_base.h is included.
+ */
+#define FSW_DEBUG_LEVEL 0
+#endif
+
+// message printing
+
+#if FSW_DEBUG_LEVEL >= 1
+#define FSW_MSG_ASSERT(params) FSW_MSGFUNC params
+#else
+#define FSW_MSG_ASSERT(params)
+#endif
+
+#if FSW_DEBUG_LEVEL >= 2
+#define FSW_MSG_DEBUG(params) FSW_MSGFUNC params
+#else
+#define FSW_MSG_DEBUG(params)
+#endif
+
+#if FSW_DEBUG_LEVEL >= 3
+#define FSW_MSG_DEBUGV(params) FSW_MSGFUNC params
+#else
+#define FSW_MSG_DEBUGV(params)
+#endif
+
+/** Maximum size for a path, specifically symlink target paths. */
+#ifndef HOST_EFI_EDK2
+#define FSW_PATH_MAX (4096)
+#else
+/* Too big allocations are handled with alloca() */
+#define FSW_PATH_MAX (2048)
+#endif
+
+/** Helper macro for token concatenation. */
+#define FSW_CONCAT3(a,b,c) a##b##c
+/** Expands to the name of a fstype dispatch table (fsw_fstype_table) for a named file system type. */
+#define FSW_FSTYPE_TABLE_NAME(t) FSW_CONCAT3(fsw_,t,_table)
+
+/** Indicates that the block cache entry is empty. */
+#define FSW_INVALID_BNO (~0UL)
+
+
+//
+// Byte-swapping macros
+//
+
+
+/**
+ * \name Byte Order Macros
+ * Implements big endian vs. little endian awareness and conversion.
+ */
+/*@{*/
+
+typedef fsw_u16             fsw_u16_le;
+typedef fsw_u16             fsw_u16_be;
+typedef fsw_u32             fsw_u32_le;
+typedef fsw_u32             fsw_u32_be;
+typedef fsw_u64             fsw_u64_le;
+typedef fsw_u64             fsw_u64_be;
+
+#define FSW_SWAPVALUE_U16(v) ((((fsw_u16)(v) & 0xff00) >> 8) | \
+                              (((fsw_u16)(v) & 0x00ff) << 8))
+#define FSW_SWAPVALUE_U32(v) ((((fsw_u32)(v) & 0xff000000UL) >> 24) | \
+                              (((fsw_u32)(v) & 0x00ff0000UL) >> 8)  | \
+                              (((fsw_u32)(v) & 0x0000ff00UL) << 8)  | \
+                              (((fsw_u32)(v) & 0x000000ffUL) << 24))
+#define FSW_SWAPVALUE_U64(v) ((((fsw_u64)(v) & 0xff00000000000000ULL) >> 56) | \
+                              (((fsw_u64)(v) & 0x00ff000000000000ULL) >> 40) | \
+                              (((fsw_u64)(v) & 0x0000ff0000000000ULL) >> 24) | \
+                              (((fsw_u64)(v) & 0x000000ff00000000ULL) >> 8)  | \
+                              (((fsw_u64)(v) & 0x00000000ff000000ULL) << 8)  | \
+                              (((fsw_u64)(v) & 0x0000000000ff0000ULL) << 24) | \
+                              (((fsw_u64)(v) & 0x000000000000ff00ULL) << 40) | \
+                              (((fsw_u64)(v) & 0x00000000000000ffULL) << 56))
+
+#ifdef FSW_LITTLE_ENDIAN
+
+#define fsw_u16_le_swap(v) (v)
+#define fsw_u16_be_swap(v) FSW_SWAPVALUE_U16(v)
+#define fsw_u32_le_swap(v) (v)
+#define fsw_u32_be_swap(v) FSW_SWAPVALUE_U32(v)
+#define fsw_u64_le_swap(v) (v)
+#define fsw_u64_be_swap(v) FSW_SWAPVALUE_U64(v)
+
+#define fsw_u16_le_sip(var)
+#define fsw_u16_be_sip(var) (var = FSW_SWAPVALUE_U16(var))
+#define fsw_u32_le_sip(var)
+#define fsw_u32_be_sip(var) (var = FSW_SWAPVALUE_U32(var))
+#define fsw_u64_le_sip(var)
+#define fsw_u64_be_sip(var) (var = FSW_SWAPVALUE_U64(var))
+
+#else
+#ifdef FSW_BIG_ENDIAN
+
+#define fsw_u16_le_swap(v) FSW_SWAPVALUE_U16(v)
+#define fsw_u16_be_swap(v) (v)
+#define fsw_u32_le_swap(v) FSW_SWAPVALUE_U32(v)
+#define fsw_u32_be_swap(v) (v)
+#define fsw_u64_le_swap(v) FSW_SWAPVALUE_U64(v)
+#define fsw_u64_be_swap(v) (v)
+
+#define fsw_u16_le_sip(var) (var = FSW_SWAPVALUE_U16(var))
+#define fsw_u16_be_sip(var)
+#define fsw_u32_le_sip(var) (var = FSW_SWAPVALUE_U32(var))
+#define fsw_u32_be_sip(var)
+#define fsw_u64_le_sip(var) (var = FSW_SWAPVALUE_U64(var))
+#define fsw_u64_be_sip(var)
+
+#endif
+#endif
+
+/*@}*/
+
+
+//
+// The following evil hack avoids a lot of casts between generic and fstype-specific
+// structures.
+//
+
+#ifndef VOLSTRUCTNAME
+#define VOLSTRUCTNAME fsw_volume
+#else
+struct VOLSTRUCTNAME;
+#endif
+#ifndef DNODESTRUCTNAME
+#define DNODESTRUCTNAME fsw_dnode
+#else
+struct DNODESTRUCTNAME;
+#endif
+
+
+/**
+ * Status code type, returned from all functions that can fail.
+ */
+typedef int fsw_status_t;
+
+/**
+ * Possible status codes.
+ */
+enum {
+    FSW_SUCCESS,
+    FSW_OUT_OF_MEMORY,
+    FSW_IO_ERROR,
+    FSW_UNSUPPORTED,
+    FSW_NOT_FOUND,
+    FSW_VOLUME_CORRUPTED,
+    FSW_UNKNOWN_ERROR
+};
+
+
+/**
+ * Core: A string with explicit length and encoding information.
+ */
+
+struct fsw_string {
+    int         type;               //!< Encoding of the string - empty, ISO-8859-1, UTF8, UTF16
+    int         len;                //!< Length in characters
+    int         size;               //!< Total data size in bytes
+    void        *data;              //!< Data pointer (may be NULL if type is EMPTY or len is zero)
+};
+
+/**
+ * Possible string types / encodings. In the case of FSW_STRING_TYPE_EMPTY,
+ * all other members of the fsw_string structure may be invalid.
+ */
+enum {
+    FSW_STRING_TYPE_EMPTY,
+    FSW_STRING_TYPE_ISO88591,
+    FSW_STRING_TYPE_UTF8,
+    FSW_STRING_TYPE_UTF16,
+    FSW_STRING_TYPE_UTF16_SWAPPED
+};
+
+#ifdef FSW_LITTLE_ENDIAN
+#define FSW_STRING_TYPE_UTF16_LE FSW_STRING_TYPE_UTF16
+#define FSW_STRING_TYPE_UTF16_BE FSW_STRING_TYPE_UTF16_SWAPPED
+#else
+#define FSW_STRING_TYPE_UTF16_LE FSW_STRING_TYPE_UTF16_SWAPPED
+#define FSW_STRING_TYPE_UTF16_BE FSW_STRING_TYPE_UTF16
+#endif
+
+/** Static initializer for an empty string. */
+#define FSW_STRING_INIT { FSW_STRING_TYPE_EMPTY, 0, 0, NULL }
+
+
+/* forward declarations */
+
+struct fsw_dnode;
+struct fsw_host_table;
+struct fsw_fstype_table;
+
+struct fsw_blockcache {
+    fsw_u32     refcount;           //!< Reference count
+    fsw_u32     cache_level;        //!< Level of importance of this block
+    fsw_u32     phys_bno;           //!< Physical block number
+    void        *data;              //!< Block data buffer
+};
+
+/**
+ * Core: Represents a mounted volume.
+ */
+
+struct fsw_volume {
+    fsw_u32     phys_blocksize;     //!< Block size for disk access / file system structures
+    fsw_u32     log_blocksize;      //!< Block size for logical file data
+
+    struct DNODESTRUCTNAME *root;   //!< Root directory dnode
+    struct fsw_string label;        //!< Volume label
+
+    struct fsw_dnode *dnode_head;   //!< List of all dnodes allocated for this volume
+
+    struct fsw_blockcache *bcache;  //!< Array of block cache entries
+    fsw_u32     bcache_size;        //!< Number of entries in the block cache array
+
+    void        *host_data;         //!< Hook for a host-specific data structure
+    struct fsw_host_table *host_table;      //!< Dispatch table for host-specific functions
+    struct fsw_fstype_table *fstype_table;  //!< Dispatch table for file system specific functions
+    int         host_string_type;   //!< String type used by the host environment
+};
+
+/**
+ * Core: Represents a "directory node" - a file, directory, symlink, whatever.
+ */
+
+struct fsw_dnode {
+    fsw_u32     refcount;           //!< Reference count
+
+    struct VOLSTRUCTNAME *vol;      //!< The volume this dnode belongs to
+    struct DNODESTRUCTNAME *parent; //!< Parent directory dnode
+    struct fsw_string name;         //!< Name of this item in the parent directory
+
+    fsw_u32     dnode_id;           //!< Unique id number (usually the inode number)
+    int         type;               //!< Type of the dnode - file, dir, symlink, special
+    fsw_u64     size;               //!< Data size in bytes
+
+    struct fsw_dnode *next;         //!< Doubly-linked list of all dnodes: previous dnode
+    struct fsw_dnode *prev;         //!< Doubly-linked list of all dnodes: next dnode
+};
+
+/**
+ * Possible dnode types. FSW_DNODE_TYPE_UNKNOWN may only be used before
+ * fsw_dnode_fill has been called on the dnode.
+ */
+enum {
+    FSW_DNODE_TYPE_UNKNOWN,
+    FSW_DNODE_TYPE_FILE,
+    FSW_DNODE_TYPE_DIR,
+    FSW_DNODE_TYPE_SYMLINK,
+    FSW_DNODE_TYPE_SPECIAL
+};
+
+/**
+ * Core: Stores the mapping of a region of a file to the data on disk.
+ */
+
+struct fsw_extent {
+    fsw_u32     type;               //!< Type of extent specification
+    fsw_u32     log_start;          //!< Starting logical block number
+    fsw_u32     log_count;          //!< Logical block count
+    fsw_u32     phys_start;         //!< Starting physical block number (for FSW_EXTENT_TYPE_PHYSBLOCK only)
+    void        *buffer;            //!< Allocated buffer pointer (for FSW_EXTENT_TYPE_BUFFER only)
+};
+
+/**
+ * Possible extent representation types. FSW_EXTENT_TYPE_INVALID is for shandle's
+ * internal use only, it must not be returned from a get_extent function.
+ */
+enum {
+    FSW_EXTENT_TYPE_INVALID,
+    FSW_EXTENT_TYPE_SPARSE,
+    FSW_EXTENT_TYPE_PHYSBLOCK,
+    FSW_EXTENT_TYPE_BUFFER
+};
+
+/**
+ * Core: An access structure to a dnode's raw data. There can be multiple
+ * shandles per dnode, each of them has its own position pointer.
+ */
+
+struct fsw_shandle {
+    struct fsw_dnode *dnode;        //!< The dnode this handle reads data from
+
+    fsw_u64     pos;                //!< Current file pointer in bytes
+    struct fsw_extent extent;       //!< Current extent
+};
+
+/**
+ * Core: Used in gathering detailed information on a volume.
+ */
+
+struct fsw_volume_stat {
+    fsw_u64     total_bytes;        //!< Total size of data area size in bytes
+    fsw_u64     free_bytes;         //!< Bytes still available for storing file data
+};
+
+/**
+ * Core: Used in gathering detailed information on a dnode.
+ */
+
+struct fsw_dnode_stat {
+    fsw_u64     used_bytes;         //!< Bytes actually used by the file on disk
+    void        (*store_time_posix)(struct fsw_dnode_stat *sb, int which, fsw_u32 posix_time);   //!< Callback for storing a Posix-style timestamp
+    void        (*store_attr_posix)(struct fsw_dnode_stat *sb, fsw_u16 posix_mode);   //!< Callback for storing a Posix-style file mode
+    void        *host_data;         //!< Hook for a host-specific data structure
+};
+
+/**
+ * Type of the timestamp passed into store_time_posix.
+ */
+enum {
+    FSW_DNODE_STAT_CTIME,
+    FSW_DNODE_STAT_MTIME,
+    FSW_DNODE_STAT_ATIME
+};
+
+/**
+ * Core: Function table for a host environment.
+ */
+
+struct fsw_host_table
+{
+    int         native_string_type; //!< String type used by the host environment
+
+    void         (*change_blocksize)(struct fsw_volume *vol,
+                                     fsw_u32 old_phys_blocksize, fsw_u32 old_log_blocksize,
+                                     fsw_u32 new_phys_blocksize, fsw_u32 new_log_blocksize);
+    fsw_status_t (*read_block)(struct fsw_volume *vol, fsw_u32 phys_bno, void *buffer);
+};
+
+/**
+ * Core: Function table for a file system driver.
+ */
+
+struct fsw_fstype_table
+{
+    struct fsw_string name;         //!< String giving the name of the file system
+    fsw_u32     volume_struct_size; //!< Size for allocating the fsw_volume structure
+    fsw_u32     dnode_struct_size;  //!< Size for allocating the fsw_dnode structure
+
+    fsw_status_t (*volume_mount)(struct VOLSTRUCTNAME *vol);
+    void         (*volume_free)(struct VOLSTRUCTNAME *vol);
+    fsw_status_t (*volume_stat)(struct VOLSTRUCTNAME *vol, struct fsw_volume_stat *sb);
+
+    fsw_status_t (*dnode_fill)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno);
+    void         (*dnode_free)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno);
+    fsw_status_t (*dnode_stat)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno,
+                               struct fsw_dnode_stat *sb);
+    fsw_status_t (*get_extent)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno,
+                               struct fsw_extent *extent);
+
+    fsw_status_t (*dir_lookup)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno,
+                               struct fsw_string *lookup_name, struct DNODESTRUCTNAME **child_dno);
+    fsw_status_t (*dir_read)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno,
+                             struct fsw_shandle *shand, struct DNODESTRUCTNAME **child_dno);
+    fsw_status_t (*readlink)(struct VOLSTRUCTNAME *vol, struct DNODESTRUCTNAME *dno,
+                             struct fsw_string *link_target);
+};
+
+
+/**
+ * \name Volume Functions
+ */
+/*@{*/
+
+fsw_status_t fsw_mount(void *host_data,
+                       struct fsw_host_table *host_table,
+                       struct fsw_fstype_table *fstype_table,
+                       struct fsw_volume **vol_out);
+void         fsw_unmount(struct fsw_volume *vol);
+fsw_status_t fsw_volume_stat(struct fsw_volume *vol, struct fsw_volume_stat *sb);
+
+void         fsw_set_blocksize(struct VOLSTRUCTNAME *vol, fsw_u32 phys_blocksize, fsw_u32 log_blocksize);
+fsw_status_t fsw_block_get(struct VOLSTRUCTNAME *vol, fsw_u32 phys_bno, fsw_u32 cache_level, void **buffer_out);
+void         fsw_block_release(struct VOLSTRUCTNAME *vol, fsw_u32 phys_bno, void *buffer);
+
+/*@}*/
+
+
+/**
+ * \name dnode Functions
+ */
+/*@{*/
+
+fsw_status_t fsw_dnode_create_root(struct VOLSTRUCTNAME *vol, fsw_u32 dnode_id, struct DNODESTRUCTNAME **dno_out);
+fsw_status_t fsw_dnode_create(struct DNODESTRUCTNAME *parent_dno, fsw_u32 dnode_id, int type,
+                              struct fsw_string *name, struct DNODESTRUCTNAME **dno_out);
+void         fsw_dnode_retain(struct fsw_dnode *dno);
+void         fsw_dnode_release(struct fsw_dnode *dno);
+
+fsw_status_t fsw_dnode_fill(struct fsw_dnode *dno);
+fsw_status_t fsw_dnode_stat(struct fsw_dnode *dno, struct fsw_dnode_stat *sb);
+
+fsw_status_t fsw_dnode_lookup(struct fsw_dnode *dno,
+                              struct fsw_string *lookup_name, struct fsw_dnode **child_dno_out);
+fsw_status_t fsw_dnode_lookup_path(struct fsw_dnode *dno,
+                                   struct fsw_string *lookup_path, char separator,
+                                   struct fsw_dnode **child_dno_out);
+fsw_status_t fsw_dnode_dir_read(struct fsw_shandle *shand, struct fsw_dnode **child_dno_out);
+fsw_status_t fsw_dnode_readlink(struct fsw_dnode *dno, struct fsw_string *link_target);
+fsw_status_t fsw_dnode_readlink_data(struct DNODESTRUCTNAME *dno, struct fsw_string *link_target);
+fsw_status_t fsw_dnode_resolve(struct fsw_dnode *dno, struct fsw_dnode **target_dno_out);
+
+/*@}*/
+
+
+/**
+ * \name shandle Functions
+ */
+/*@{*/
+
+fsw_status_t fsw_shandle_open(struct DNODESTRUCTNAME *dno, struct fsw_shandle *shand);
+void         fsw_shandle_close(struct fsw_shandle *shand);
+fsw_status_t fsw_shandle_read(struct fsw_shandle *shand, fsw_u32 *buffer_size_inout, void *buffer);
+
+/*@}*/
+
+
+/**
+ * \name Memory Functions
+ */
+/*@{*/
+
+fsw_status_t fsw_alloc_zero(int len, void **ptr_out);
+fsw_status_t fsw_memdup(void **dest_out, void *src, int len);
+
+/*@}*/
+
+
+/**
+ * \name String Functions
+ */
+/*@{*/
+
+int          fsw_strlen(struct fsw_string *s);
+int          fsw_streq(struct fsw_string *s1, struct fsw_string *s2);
+int          fsw_streq_cstr(struct fsw_string *s1, const char *s2);
+fsw_status_t fsw_strdup_coerce(struct fsw_string *dest, int type, struct fsw_string *src);
+void         fsw_strsplit(struct fsw_string *lookup_name, struct fsw_string *buffer, char separator);
+
+void         fsw_strfree(struct fsw_string *s);
+fsw_u16      fsw_to_lower(fsw_u16 ch);
+
+/*@}*/
+
+/**
+ * \name Posix Mode Macros
+ * These macros can be used globally to test fields and bits in
+ * Posix-style modes.
+ *
+ * Taken from FreeBSD sys/stat.h.
+ */
+/*@{*/
+#ifndef S_IRWXU
+
+#define	S_ISUID	0004000			/* set user id on execution */
+#define	S_ISGID	0002000			/* set group id on execution */
+#define	S_ISTXT	0001000			/* sticky bit */
+
+#define	S_IRWXU	0000700			/* RWX mask for owner */
+#define	S_IRUSR	0000400			/* R for owner */
+#define	S_IWUSR	0000200			/* W for owner */
+#define	S_IXUSR	0000100			/* X for owner */
+
+#define	S_IRWXG	0000070			/* RWX mask for group */
+#define	S_IRGRP	0000040			/* R for group */
+#define	S_IWGRP	0000020			/* W for group */
+#define	S_IXGRP	0000010			/* X for group */
+
+#define	S_IRWXO	0000007			/* RWX mask for other */
+#define	S_IROTH	0000004			/* R for other */
+#define	S_IWOTH	0000002			/* W for other */
+#define	S_IXOTH	0000001			/* X for other */
+
+#define	S_IFMT	 0170000		/* type of file mask */
+#define	S_IFIFO	 0010000		/* named pipe (fifo) */
+#define	S_IFCHR	 0020000		/* character special */
+#define	S_IFDIR	 0040000		/* directory */
+#define	S_IFBLK	 0060000		/* block special */
+#define	S_IFREG	 0100000		/* regular */
+#define	S_IFLNK	 0120000		/* symbolic link */
+#define	S_IFSOCK 0140000		/* socket */
+#define	S_ISVTX	 0001000		/* save swapped text even after use */
+#define	S_IFWHT  0160000		/* whiteout */
+
+#define	S_ISDIR(m)	(((m) & 0170000) == 0040000)	/* directory */
+#define	S_ISCHR(m)	(((m) & 0170000) == 0020000)	/* char special */
+#define	S_ISBLK(m)	(((m) & 0170000) == 0060000)	/* block special */
+#define	S_ISREG(m)	(((m) & 0170000) == 0100000)	/* regular file */
+#define	S_ISFIFO(m)	(((m) & 0170000) == 0010000)	/* fifo or socket */
+#define	S_ISLNK(m)	(((m) & 0170000) == 0120000)	/* symbolic link */
+#define	S_ISSOCK(m)	(((m) & 0170000) == 0140000)	/* socket */
+#define	S_ISWHT(m)	(((m) & 0170000) == 0160000)	/* whiteout */
+
+#define S_BLKSIZE	512		/* block size used in the stat struct */
+
+#endif
+/*@}*/
+
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_efi.c b/ExtPkg/ExtPkgDxe/fsw_efi.c
new file mode 100644
index 0000000..9a4a739
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_efi.c
@@ -0,0 +1,1167 @@ 
+/* $Id: fsw_efi.c 29125 2010-05-06 09:43:05Z vboxsync $ */
+/** @file
+ * fsw_efi.c - EFI host environment code.
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Ext.h"
+#include "fsw_efi.h"
+#include "fsw_core.h"
+
+#define DEBUG_LEVEL 0
+#define FSTYPE ext4
+#ifndef FSTYPE
+#error FSTYPE must be defined!
+#endif
+
+#define DEBUG_VBFS 0
+
+#if DEBUG_VBFS==2
+#define DBG(x...)  AsciiPrint(x)
+#elif DEBUG_VBFS==1
+#define DBG(x...)  BootLog(x)
+#else
+#define DBG(x...)
+#endif
+
+/** Helper macro for stringification. */
+#define FSW_EFI_STRINGIFY(x) #x
+
+// function prototypes
+EFI_STATUS EFIAPI fsw_efi_DriverBinding_Supported(IN EFI_DRIVER_BINDING_PROTOCOL  *This,
+                                                  IN EFI_HANDLE                   ControllerHandle,
+                                                  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath);
+EFI_STATUS EFIAPI fsw_efi_DriverBinding_Start(IN EFI_DRIVER_BINDING_PROTOCOL  *This,
+                                              IN EFI_HANDLE                   ControllerHandle,
+                                              IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath);
+EFI_STATUS EFIAPI fsw_efi_DriverBinding_Stop(IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
+                                             IN  EFI_HANDLE                   ControllerHandle,
+                                             IN  UINTN                        NumberOfChildren,
+                                             IN  EFI_HANDLE                   *ChildHandleBuffer);
+
+void fsw_efi_change_blocksize(struct fsw_volume *vol,
+                              fsw_u32 old_phys_blocksize, fsw_u32 old_log_blocksize,
+                              fsw_u32 new_phys_blocksize, fsw_u32 new_log_blocksize);
+fsw_status_t fsw_efi_read_block(struct fsw_volume *vol, fsw_u32 phys_bno, void *buffer);
+
+EFI_STATUS fsw_efi_map_status(fsw_status_t fsw_status, FSW_VOLUME_DATA *Volume);
+
+EFI_STATUS EFIAPI fsw_efi_FileSystem_OpenVolume(IN EFI_FILE_IO_INTERFACE *This,
+                                                OUT EFI_FILE **Root);
+EFI_STATUS fsw_efi_dnode_to_FileHandle(IN struct fsw_dnode *dno,
+                                       OUT EFI_FILE **NewFileHandle);
+
+EFI_STATUS fsw_efi_file_read(IN FSW_FILE_DATA *File,
+                             IN OUT UINTN *BufferSize,
+                             OUT VOID *Buffer);
+EFI_STATUS fsw_efi_file_getpos(IN FSW_FILE_DATA *File,
+                               OUT UINT64 *Position);
+EFI_STATUS fsw_efi_file_setpos(IN FSW_FILE_DATA *File,
+                               IN UINT64 Position);
+
+EFI_STATUS fsw_efi_dir_open(IN FSW_FILE_DATA *File,
+                            OUT EFI_FILE **NewHandle,
+                            IN CHAR16 *FileName,
+                            IN UINT64 OpenMode,
+                            IN UINT64 Attributes);
+EFI_STATUS fsw_efi_dir_read(IN FSW_FILE_DATA *File,
+                            IN OUT UINTN *BufferSize,
+                            OUT VOID *Buffer);
+EFI_STATUS fsw_efi_dir_setpos(IN FSW_FILE_DATA *File,
+                              IN UINT64 Position);
+
+EFI_STATUS fsw_efi_dnode_getinfo(IN FSW_FILE_DATA *File,
+                                 IN EFI_GUID *InformationType,
+                                 IN OUT UINTN *BufferSize,
+                                 OUT VOID *Buffer);
+EFI_STATUS fsw_efi_dnode_fill_FileInfo(IN FSW_VOLUME_DATA *Volume,
+                                       IN struct fsw_dnode *dno,
+                                       IN OUT UINTN *BufferSize,
+                                       OUT VOID *Buffer);
+
+/**
+ * Interface structure for the EFI Driver Binding protocol.
+ */
+
+EFI_DRIVER_BINDING_PROTOCOL fsw_efi_DriverBinding_table = {
+    fsw_efi_DriverBinding_Supported,
+    fsw_efi_DriverBinding_Start,
+    fsw_efi_DriverBinding_Stop,
+    0xa,
+    NULL,
+    NULL
+};
+
+//forward declaration
+EFI_STATUS
+EFIAPI
+ExtComponentNameGetDriverName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL  *This,
+  IN  CHAR8                        *Language,
+  OUT CHAR16                       **DriverName
+  );
+
+EFI_STATUS
+EFIAPI
+ExtComponentNameGetControllerName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL                     *This,
+  IN  EFI_HANDLE                                      ControllerHandle,
+  IN  EFI_HANDLE                                      ChildHandle        OPTIONAL,
+  IN  CHAR8                                           *Language,
+  OUT CHAR16                                          **ControllerName
+  );
+
+//
+// EFI Component Name Protocol
+//
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL  gExtComponentName = { 
+  ExtComponentNameGetDriverName,
+  ExtComponentNameGetControllerName,
+  "eng"
+};
+
+//
+// EFI Component Name 2 Protocol
+//
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL gExtComponentName2 = { 
+  (EFI_COMPONENT_NAME2_GET_DRIVER_NAME) ExtComponentNameGetDriverName,
+  (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) ExtComponentNameGetControllerName,
+  "en"
+};
+
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mExtDriverNameTable[] = {
+  {
+    "eng;en",
+    L"Ext File System Driver"
+  },
+  {
+    NULL,
+    NULL
+  }
+};
+
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mExtControllerNameTable[] = {
+  {
+    "eng;en",
+    L"Ext File System"
+  },
+  {
+    NULL,
+    NULL
+  }
+};
+
+EFI_STATUS
+EFIAPI
+ExtComponentNameGetDriverName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL  *This,
+  IN  CHAR8                        *Language,
+  OUT CHAR16                       **DriverName
+  )
+{
+#if DEBUG_LEVEL
+	Print(L" ExtComponentNameGetDriverName called\n");
+#endif
+
+  return LookupUnicodeString2 (
+           Language,
+           This->SupportedLanguages,
+           mExtDriverNameTable,
+           DriverName,
+           (BOOLEAN)(This == &gExtComponentName)
+           );
+}
+
+EFI_STATUS
+EFIAPI
+ExtComponentNameGetControllerName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL                     *This,
+  IN  EFI_HANDLE                                      ControllerHandle,
+  IN  EFI_HANDLE                                      ChildHandle        OPTIONAL,
+  IN  CHAR8                                           *Language,
+  OUT CHAR16                                          **ControllerName
+  )
+{
+  EFI_STATUS  Status;
+#if DEBUG_LEVEL
+	Print(L"ExtComponentNameGetControllerName called\n");
+#endif
+  //
+  // This is a device driver, so ChildHandle must be NULL.
+  //
+  if (ChildHandle != NULL) {
+    return EFI_UNSUPPORTED;
+  }
+
+  //
+  // Make sure this driver is currently managing ControllHandle
+  //
+  Status = EfiTestManagedDevice (
+             ControllerHandle,
+             fsw_efi_DriverBinding_table.DriverBindingHandle,
+             &gEfiDiskIoProtocolGuid
+             );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  return LookupUnicodeString2 (
+           Language,
+           This->SupportedLanguages,
+           mExtControllerNameTable,
+           ControllerName,
+           (BOOLEAN)(This == &gExtComponentName)
+           );
+}
+
+/**
+ * Dispatch table for our FSW host driver.
+ */
+
+struct fsw_host_table   fsw_efi_host_table = {
+    FSW_STRING_TYPE_UTF16,
+    fsw_efi_change_blocksize,
+    fsw_efi_read_block
+};
+
+extern struct fsw_fstype_table   FSW_FSTYPE_TABLE_NAME(FSTYPE);
+
+
+/**
+ * Image entry point. Installs the Driver Binding and Component Name protocols
+ * on the image's handle. Actually mounting a file system is initiated through
+ * the Driver Binding protocol at the firmware's request.
+ */
+EFI_STATUS EFIAPI fsw_efi_main(IN EFI_HANDLE         ImageHandle,
+                               IN EFI_SYSTEM_TABLE   *SystemTable)
+{
+    EFI_STATUS  Status;
+		Status = EfiLibInstallDriverBindingComponentName2 (
+             ImageHandle,
+             SystemTable,
+             &fsw_efi_DriverBinding_table,
+             ImageHandle,
+             &gExtComponentName,
+             &gExtComponentName2
+             );  
+  	ASSERT_EFI_ERROR (Status);
+    return EFI_SUCCESS;
+}
+
+#ifdef __MAKEWITH_GNUEFI
+EFI_DRIVER_ENTRY_POINT(fsw_efi_main)
+#endif
+
+EFI_STATUS
+EFIAPI
+ExtUnload (
+  IN EFI_HANDLE  ImageHandle
+  )
+{
+  EFI_STATUS  Status;
+  EFI_HANDLE  *DeviceHandleBuffer;
+  UINTN       DeviceHandleCount;
+  UINTN       Index;
+
+  Status = gBS->LocateHandleBuffer (
+                  AllHandles,
+                  NULL,
+                  NULL,
+                  &DeviceHandleCount,
+                  &DeviceHandleBuffer
+                  );
+  if (!EFI_ERROR (Status)) {
+    for (Index = 0; Index < DeviceHandleCount; Index++) {
+      Status = gBS->DisconnectController (
+                      DeviceHandleBuffer[Index],
+                      ImageHandle,
+                      NULL
+                      );
+    }
+
+    if (DeviceHandleBuffer != NULL) {
+      FreePool (DeviceHandleBuffer);
+    }
+  }
+  return Status;
+}
+
+/**
+ * Driver Binding EFI protocol, Supported function. This function is called by EFI
+ * to test if this driver can handle a certain device. Our implementation only checks
+ * if the device is a disk (i.e. that it supports the Block I/O and Disk I/O protocols)
+ * and implicitly checks if the disk is already in use by another driver.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_DriverBinding_Supported(IN EFI_DRIVER_BINDING_PROTOCOL  *This,
+                                                  IN EFI_HANDLE                   ControllerHandle,
+                                                  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath)
+{
+    EFI_STATUS          Status;
+    EFI_DISK_IO         *DiskIo;
+
+    // we check for both DiskIO and BlockIO protocols
+    // first, open DiskIO
+    Status = gBS->OpenProtocol (
+										ControllerHandle,
+                    &gEfiDiskIoProtocolGuid,
+                    (VOID **) &DiskIo,
+                    This->DriverBindingHandle,
+                    ControllerHandle,
+                    EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL
+										);
+    if (EFI_ERROR(Status))
+        return Status;
+
+    // we were just checking, close it again
+    gBS->CloseProtocol(ControllerHandle,
+                      &gEfiDiskIoProtocolGuid,
+                      This->DriverBindingHandle,
+                      ControllerHandle);
+
+    // next, check BlockIO without actually opening it
+    Status = gBS->OpenProtocol(ControllerHandle,
+                              &gEfiBlockIoProtocolGuid,
+                              NULL,
+                              This->DriverBindingHandle,
+                              ControllerHandle,
+                              EFI_OPEN_PROTOCOL_TEST_PROTOCOL);
+    return Status;
+}
+
+/**
+ * Driver Binding EFI protocol, Start function. This function is called by EFI
+ * to start driving the given device. It is still possible at this point to
+ * return EFI_UNSUPPORTED, and in fact we will do so if the file system driver
+ * cannot find the superblock signature (or equivalent) that it expects.
+ *
+ * This function allocates memory for a per-volume structure, opens the
+ * required protocols (just Disk I/O in our case, Block I/O is only looked
+ * at to get the MediaId field), and lets the FSW core mount the file system.
+ * If successful, an EFI Simple File System protocol is exported on the
+ * device handle.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_DriverBinding_Start(IN EFI_DRIVER_BINDING_PROTOCOL  *This,
+                                              IN EFI_HANDLE                   ControllerHandle,
+                                              IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath)
+{
+    EFI_STATUS          Status;
+    EFI_BLOCK_IO        *BlockIo;
+    EFI_DISK_IO         *DiskIo;
+    FSW_VOLUME_DATA     *Volume;
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_DriverBinding_Start\n");
+#endif
+
+    // open consumed protocols
+    Status = gBS->OpenProtocol(ControllerHandle,
+															&gEfiBlockIoProtocolGuid,
+                              (VOID **) &BlockIo,
+                              This->DriverBindingHandle,
+                              ControllerHandle,
+                              EFI_OPEN_PROTOCOL_GET_PROTOCOL);   // NOTE: we only want to look at the MediaId
+    if (EFI_ERROR(Status)) {
+#if DEBUG_LEVEL
+        Print(L"Fsw ERROR: OpenProtocol(BlockIo) returned %x\n", Status);
+#endif
+        return Status;
+    }
+
+    Status = gBS->OpenProtocol( ControllerHandle,
+                              &gEfiDiskIoProtocolGuid,
+                              (VOID **) &DiskIo,
+                              This->DriverBindingHandle,
+                              ControllerHandle,
+                              EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL);
+    if (EFI_ERROR(Status)) {
+#if DEBUG_LEVEL
+        Print(L"Fsw ERROR: OpenProtocol(DiskIo) returned %r\n", Status);
+#endif
+        return Status;
+    }
+
+    // allocate volume structure
+    Volume = AllocateZeroPool(sizeof(FSW_VOLUME_DATA));
+    Volume->Signature       = FSW_VOLUME_DATA_SIGNATURE;
+    Volume->Handle          = ControllerHandle;
+    Volume->DiskIo          = DiskIo;
+    Volume->MediaId         = BlockIo->Media->MediaId;
+    Volume->LastIOStatus    = EFI_SUCCESS;
+
+    // mount the filesystem
+    Status = fsw_efi_map_status(fsw_mount(Volume, &fsw_efi_host_table,
+                                          &FSW_FSTYPE_TABLE_NAME(FSTYPE), &Volume->vol),
+                                Volume);
+
+    if (!EFI_ERROR(Status)) {
+#if DEBUG_LEVEL
+        Print(L"Fsw success register the SimpleFileSystem protocol %x\n", Status);
+#endif
+        // register the SimpleFileSystem protocol
+        Volume->FileSystem.Revision     = EFI_FILE_IO_INTERFACE_REVISION;
+        Volume->FileSystem.OpenVolume   = fsw_efi_FileSystem_OpenVolume;
+        Status = gBS->InstallMultipleProtocolInterfaces( &ControllerHandle,
+                                                       &gEfiSimpleFileSystemProtocolGuid,
+                                                       &Volume->FileSystem,
+                                                       NULL);
+        if (EFI_ERROR(Status)) {
+#if DEBUG_LEVEL
+            Print(L"Fsw ERROR: InstallMultipleProtocolInterfaces returned %x\n", Status);
+#endif
+        }
+    }
+
+    // on errors, close the opened protocols
+    if (EFI_ERROR(Status)) {
+        if (Volume->vol != NULL)
+            fsw_unmount(Volume->vol);
+        FreePool(Volume);
+
+        gBS->CloseProtocol( ControllerHandle,
+                          &gEfiDiskIoProtocolGuid,
+                          This->DriverBindingHandle,
+                          ControllerHandle);
+    }
+#if DEBUG_LEVEL
+		Print(L"fsw_efi_DriverBinding_Start returned %x\n", Status);	
+#endif
+    return Status;
+}
+
+/**
+ * Driver Binding EFI protocol, Stop function. This function is called by EFI
+ * to stop the driver on the given device. This translates to an unmount
+ * call for the FSW core.
+ *
+ * We assume that all file handles on the volume have been closed before
+ * the driver is stopped. At least with the EFI shell, that is actually the
+ * case; it closes all file handles between commands.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_DriverBinding_Stop(IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
+                                             IN  EFI_HANDLE                   ControllerHandle,
+                                             IN  UINTN                        NumberOfChildren,
+                                             IN  EFI_HANDLE                   *ChildHandleBuffer)
+{
+    EFI_STATUS          Status;
+    EFI_FILE_IO_INTERFACE *FileSystem;
+    FSW_VOLUME_DATA     *Volume;
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_DriverBinding_Stop\n");
+#endif
+
+    // get the installed SimpleFileSystem interface
+    Status = gBS->OpenProtocol( ControllerHandle,
+                              &gEfiSimpleFileSystemProtocolGuid,
+                              (VOID **) &FileSystem,
+                              This->DriverBindingHandle,
+                              ControllerHandle,
+                              EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+    if (EFI_ERROR(Status)){
+        return EFI_UNSUPPORTED;
+		}
+
+    // get private data structure
+    Volume = FSW_VOLUME_FROM_FILE_SYSTEM(FileSystem);
+
+    // uninstall Simple File System protocol
+    Status = gBS->UninstallMultipleProtocolInterfaces( ControllerHandle,
+                                                     &gEfiSimpleFileSystemProtocolGuid, &Volume->FileSystem,
+                                                     NULL);
+    if (EFI_ERROR(Status)) {
+#if DEBUG_LEVEL
+        Print(L"Fsw ERROR: UninstallMultipleProtocolInterfaces returned %x\n", Status);
+#endif
+        return Status;
+    }
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_DriverBinding_Stop: protocol uninstalled successfully\n");
+#endif
+
+    // release private data structure
+    if (Volume->vol != NULL)
+        fsw_unmount(Volume->vol);
+    FreePool(Volume);
+
+    // close the consumed protocols
+    Status = gBS->CloseProtocol( ControllerHandle,
+                               &gEfiDiskIoProtocolGuid,
+                               This->DriverBindingHandle,
+                               ControllerHandle);
+
+    return Status;
+}
+
+/**
+ * FSW interface function for block size changes. This function is called by the FSW core
+ * when the file system driver changes the block sizes for the volume.
+ */
+
+void fsw_efi_change_blocksize(struct fsw_volume *vol,
+                              fsw_u32 old_phys_blocksize, fsw_u32 old_log_blocksize,
+                              fsw_u32 new_phys_blocksize, fsw_u32 new_log_blocksize)
+{
+    // nothing to do
+}
+
+/**
+ * FSW interface function to read data blocks. This function is called by the FSW core
+ * to read a block of data from the device. The buffer is allocated by the core code.
+ */
+
+fsw_status_t fsw_efi_read_block(struct fsw_volume *vol, fsw_u32 phys_bno, void *buffer)
+{
+    EFI_STATUS          Status;
+    FSW_VOLUME_DATA     *Volume = (FSW_VOLUME_DATA *)vol->host_data;
+
+//    FSW_MSG_DEBUGV((FSW_MSGSTR("fsw_efi_read_block: %d  (%d)\n"), phys_bno, vol->phys_blocksize));
+
+    // read from disk
+    Status = Volume->DiskIo->ReadDisk( Volume->DiskIo, Volume->MediaId,
+                                      (UINT64)phys_bno * vol->phys_blocksize,
+                                      vol->phys_blocksize,
+                                      buffer);
+    Volume->LastIOStatus = Status;
+    if (EFI_ERROR(Status))
+        return FSW_IO_ERROR;
+    return FSW_SUCCESS;
+}
+
+/**
+ * Map FSW status codes to EFI status codes. The FSW_IO_ERROR code is only produced
+ * by fsw_efi_read_block, so we map it back to the EFI status code remembered from
+ * the last I/O operation.
+ */
+
+EFI_STATUS fsw_efi_map_status(fsw_status_t fsw_status, FSW_VOLUME_DATA *Volume)
+{
+    switch (fsw_status) {
+        case FSW_SUCCESS:
+            return EFI_SUCCESS;
+        case FSW_OUT_OF_MEMORY:
+            return EFI_VOLUME_CORRUPTED;
+        case FSW_IO_ERROR:
+            return Volume->LastIOStatus;
+        case FSW_UNSUPPORTED:
+            return EFI_UNSUPPORTED;
+        case FSW_NOT_FOUND:
+            return EFI_NOT_FOUND;
+        case FSW_VOLUME_CORRUPTED:
+            return EFI_VOLUME_CORRUPTED;
+        default:
+            return EFI_DEVICE_ERROR;
+    }
+}
+
+/**
+ * File System EFI protocol, OpenVolume function. Creates a file handle for
+ * the root directory and returns it. Note that this function may be called
+ * multiple times and returns a new file handle each time. Each returned
+ * handle is closed by the client using it.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileSystem_OpenVolume(IN EFI_FILE_IO_INTERFACE *This,
+                                                OUT EFI_FILE **Root)
+{
+    EFI_STATUS          Status;
+    FSW_VOLUME_DATA     *Volume = FSW_VOLUME_FROM_FILE_SYSTEM(This);
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_FileSystem_OpenVolume\n");
+#endif
+
+    Status = fsw_efi_dnode_to_FileHandle(Volume->vol->root, Root);
+
+    return Status;
+}
+
+/**
+ * File Handle EFI protocol, Open function. Dispatches the call
+ * based on the kind of file handle.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_Open(IN EFI_FILE *This,
+                                          OUT EFI_FILE **NewHandle,
+                                          IN CHAR16 *FileName,
+                                          IN UINT64 OpenMode,
+                                          IN UINT64 Attributes)
+{
+    FSW_FILE_DATA      *File = FSW_FILE_FROM_FILE_HANDLE(This);
+
+    if (File->Type == FSW_EFI_FILE_TYPE_DIR)
+        return fsw_efi_dir_open(File, NewHandle, FileName, OpenMode, Attributes);
+    // not supported for regular files
+    return EFI_UNSUPPORTED;
+}
+
+/**
+ * File Handle EFI protocol, Close function. Closes the FSW shandle
+ * and frees the memory used for the structure.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_Close(IN EFI_FILE *This)
+{
+    FSW_FILE_DATA      *File = FSW_FILE_FROM_FILE_HANDLE(This);
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_FileHandle_Close\n");
+#endif
+
+    fsw_shandle_close(&File->shand);
+    FreePool(File);
+
+    return EFI_SUCCESS;
+}
+
+/**
+ * File Handle EFI protocol, Delete function. Calls through to Close
+ * and returns a warning because this driver is read-only.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_Delete(IN EFI_FILE *This)
+{
+    EFI_STATUS          Status;
+
+    Status = This->Close( This);
+    if (Status == EFI_SUCCESS) {
+        // this driver is read-only
+        Status = EFI_WARN_DELETE_FAILURE;
+    }
+
+    return Status;
+}
+
+/**
+ * File Handle EFI protocol, Read function. Dispatches the call
+ * based on the kind of file handle.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_Read(IN EFI_FILE *This,
+                                          IN OUT UINTN *BufferSize,
+                                          OUT VOID *Buffer)
+{
+    FSW_FILE_DATA      *File = FSW_FILE_FROM_FILE_HANDLE(This);
+
+    if (File->Type == FSW_EFI_FILE_TYPE_FILE)
+        return fsw_efi_file_read(File, BufferSize, Buffer);
+    else if (File->Type == FSW_EFI_FILE_TYPE_DIR)
+        return fsw_efi_dir_read(File, BufferSize, Buffer);
+    return EFI_UNSUPPORTED;
+}
+
+/**
+ * File Handle EFI protocol, Write function. Returns unsupported status
+ * because this driver is read-only.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_Write(IN EFI_FILE *This,
+                                           IN OUT UINTN *BufferSize,
+                                           IN VOID *Buffer)
+{
+    // this driver is read-only
+    return EFI_WRITE_PROTECTED;
+}
+
+/**
+ * File Handle EFI protocol, GetPosition function. Dispatches the call
+ * based on the kind of file handle.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_GetPosition(IN EFI_FILE *This,
+                                                 OUT UINT64 *Position)
+{
+    FSW_FILE_DATA      *File = FSW_FILE_FROM_FILE_HANDLE(This);
+
+    if (File->Type == FSW_EFI_FILE_TYPE_FILE)
+        return fsw_efi_file_getpos(File, Position);
+    // not defined for directories
+    return EFI_UNSUPPORTED;
+}
+
+/**
+ * File Handle EFI protocol, SetPosition function. Dispatches the call
+ * based on the kind of file handle.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_SetPosition(IN EFI_FILE *This,
+                                                 IN UINT64 Position)
+{
+    FSW_FILE_DATA      *File = FSW_FILE_FROM_FILE_HANDLE(This);
+
+    if (File->Type == FSW_EFI_FILE_TYPE_FILE)
+        return fsw_efi_file_setpos(File, Position);
+    else if (File->Type == FSW_EFI_FILE_TYPE_DIR)
+        return fsw_efi_dir_setpos(File, Position);
+    return EFI_UNSUPPORTED;
+}
+
+/**
+ * File Handle EFI protocol, GetInfo function. Dispatches to the common
+ * function implementing this.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_GetInfo(IN EFI_FILE *This,
+                                             IN EFI_GUID *InformationType,
+                                             IN OUT UINTN *BufferSize,
+                                             OUT VOID *Buffer)
+{
+    FSW_FILE_DATA      *File = FSW_FILE_FROM_FILE_HANDLE(This);
+
+    return fsw_efi_dnode_getinfo(File, InformationType, BufferSize, Buffer);
+}
+
+/**
+ * File Handle EFI protocol, SetInfo function. Returns unsupported status
+ * because this driver is read-only.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_SetInfo(IN EFI_FILE *This,
+                                             IN EFI_GUID *InformationType,
+                                             IN UINTN BufferSize,
+                                             IN VOID *Buffer)
+{
+    // this driver is read-only
+    return EFI_WRITE_PROTECTED;
+}
+
+/**
+ * File Handle EFI protocol, Flush function. Returns unsupported status
+ * because this driver is read-only.
+ */
+
+EFI_STATUS EFIAPI fsw_efi_FileHandle_Flush(IN EFI_FILE *This)
+{
+    // this driver is read-only
+    return EFI_WRITE_PROTECTED;
+}
+
+/**
+ * Set up a file handle for a dnode. This function allocates a data structure
+ * for a file handle, opens a FSW shandle and populates the EFI_FILE structure
+ * with the interface functions.
+ */
+
+EFI_STATUS fsw_efi_dnode_to_FileHandle(IN struct fsw_dnode *dno,
+                                       OUT EFI_FILE **NewFileHandle)
+{
+    EFI_STATUS          Status;
+    FSW_FILE_DATA       *File;
+
+    // make sure the dnode has complete info
+    Status = fsw_efi_map_status(fsw_dnode_fill(dno), (FSW_VOLUME_DATA *)dno->vol->host_data);
+    if (EFI_ERROR(Status))
+        return Status;
+
+    // check type
+    if (dno->type != FSW_DNODE_TYPE_FILE && dno->type != FSW_DNODE_TYPE_DIR){
+        return EFI_UNSUPPORTED;
+		}
+
+    // allocate file structure
+    File = AllocateZeroPool(sizeof(FSW_FILE_DATA));
+    File->Signature = FSW_FILE_DATA_SIGNATURE;
+    if (dno->type == FSW_DNODE_TYPE_FILE)
+        File->Type = FSW_EFI_FILE_TYPE_FILE;
+    else if (dno->type == FSW_DNODE_TYPE_DIR)
+        File->Type = FSW_EFI_FILE_TYPE_DIR;
+
+    // open shandle
+    Status = fsw_efi_map_status(fsw_shandle_open(dno, &File->shand),
+                                (FSW_VOLUME_DATA *)dno->vol->host_data);
+    if (EFI_ERROR(Status)) {
+        FreePool(File);
+        return Status;
+    }
+
+    // populate the file handle
+    File->FileHandle.Revision    = EFI_FILE_HANDLE_REVISION;
+    File->FileHandle.Open        = fsw_efi_FileHandle_Open;
+    File->FileHandle.Close       = fsw_efi_FileHandle_Close;
+    File->FileHandle.Delete      = fsw_efi_FileHandle_Delete;
+    File->FileHandle.Read        = fsw_efi_FileHandle_Read;
+    File->FileHandle.Write       = fsw_efi_FileHandle_Write;
+    File->FileHandle.GetPosition = fsw_efi_FileHandle_GetPosition;
+    File->FileHandle.SetPosition = fsw_efi_FileHandle_SetPosition;
+    File->FileHandle.GetInfo     = fsw_efi_FileHandle_GetInfo;
+    File->FileHandle.SetInfo     = fsw_efi_FileHandle_SetInfo;
+    File->FileHandle.Flush       = fsw_efi_FileHandle_Flush;
+
+    *NewFileHandle = &File->FileHandle;
+    return EFI_SUCCESS;
+}
+
+/**
+ * Data read function for regular files. Calls through to fsw_shandle_read.
+ */
+
+EFI_STATUS fsw_efi_file_read(IN FSW_FILE_DATA *File,
+                             IN OUT UINTN *BufferSize,
+                             OUT VOID *Buffer)
+{
+    EFI_STATUS          Status;
+    fsw_u32             buffer_size;
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_file_read %d bytes\n", *BufferSize);
+#endif
+
+    buffer_size = (fsw_u32)*BufferSize;
+    Status = fsw_efi_map_status(fsw_shandle_read(&File->shand, &buffer_size, Buffer),
+                                (FSW_VOLUME_DATA *)File->shand.dnode->vol->host_data);
+    *BufferSize = buffer_size;
+
+    return Status;
+}
+
+/**
+ * Get file position for regular files.
+ */
+
+EFI_STATUS fsw_efi_file_getpos(IN FSW_FILE_DATA *File,
+                               OUT UINT64 *Position)
+{
+    *Position = File->shand.pos;
+    return EFI_SUCCESS;
+}
+
+/**
+ * Set file position for regular files. EFI specifies the all-ones value
+ * to be a special value for the end of the file.
+ */
+
+EFI_STATUS fsw_efi_file_setpos(IN FSW_FILE_DATA *File, IN UINT64 Position)
+{
+    if (Position == 0xFFFFFFFFFFFFFFFFULL)
+        File->shand.pos = File->shand.dnode->size;
+    else
+        File->shand.pos = Position;
+    return EFI_SUCCESS;
+}
+
+/**
+ * Open function used to open new file handles relative to a directory.
+ * In EFI, the "open file" function is implemented by directory file handles
+ * and is passed a relative or volume-absolute path to the file or directory
+ * to open. We use fsw_dnode_lookup_path to find the node plus an additional
+ * call to fsw_dnode_resolve because EFI has no concept of symbolic links.
+ */
+
+EFI_STATUS fsw_efi_dir_open(IN FSW_FILE_DATA *File,
+                            OUT EFI_FILE **NewHandle,
+                            IN CHAR16 *FileName,
+                            IN UINT64 OpenMode,
+                            IN UINT64 Attributes)
+{
+    EFI_STATUS          Status;
+    FSW_VOLUME_DATA     *Volume = (FSW_VOLUME_DATA *)File->shand.dnode->vol->host_data;
+    struct fsw_dnode    *dno;
+    struct fsw_dnode    *target_dno;
+    struct fsw_string   lookup_path;
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_dir_open: '%s'\n", FileName);
+#endif
+
+    if (OpenMode != EFI_FILE_MODE_READ)
+        return EFI_WRITE_PROTECTED;
+
+    lookup_path.type = FSW_STRING_TYPE_UTF16;
+    lookup_path.len  = (int)StrLen(FileName);
+    lookup_path.size = lookup_path.len * sizeof(fsw_u16);
+    lookup_path.data = FileName;
+
+    // resolve the path (symlinks along the way are automatically resolved)
+    Status = fsw_efi_map_status(fsw_dnode_lookup_path(File->shand.dnode, &lookup_path, '\\', &dno), Volume);
+    if (EFI_ERROR(Status))
+        return Status;
+
+    // if the final node is a symlink, also resolve it
+    Status = fsw_efi_map_status(fsw_dnode_resolve(dno, &target_dno), Volume);
+    fsw_dnode_release(dno);
+    if (EFI_ERROR(Status))
+        return Status;
+    dno = target_dno;
+
+    // make a new EFI handle for the target dnode
+    Status = fsw_efi_dnode_to_FileHandle(dno, NewHandle);
+    fsw_dnode_release(dno);
+    return Status;
+}
+
+/**
+ * Read function for directories. A file handle read on a directory retrieves
+ * the next directory entry.
+ */
+
+EFI_STATUS fsw_efi_dir_read(IN FSW_FILE_DATA *File,
+                            IN OUT UINTN *BufferSize,
+                            OUT VOID *Buffer)
+{
+    EFI_STATUS          Status;
+    FSW_VOLUME_DATA     *Volume = (FSW_VOLUME_DATA *)File->shand.dnode->vol->host_data;
+    struct fsw_dnode    *dno;
+
+#if DEBUG_LEVEL
+    Print(L"fsw_efi_dir_read...\n");
+#endif
+
+    // read the next entry
+    Status = fsw_efi_map_status(fsw_dnode_dir_read(&File->shand, &dno), Volume);
+    if (Status == EFI_NOT_FOUND) {
+        // end of directory
+        *BufferSize = 0;
+#if DEBUG_LEVEL
+        Print(L"...no more entries\n");
+#endif
+        return EFI_SUCCESS;
+    }
+    if (EFI_ERROR(Status))
+        return Status;
+
+    // get info into buffer
+    Status = fsw_efi_dnode_fill_FileInfo(Volume, dno, BufferSize, Buffer);
+    fsw_dnode_release(dno);
+    return Status;
+}
+
+/**
+ * Set file position for directories. The only allowed set position operation
+ * for directories is to rewind the directory completely by setting the
+ * position to zero.
+ */
+
+EFI_STATUS fsw_efi_dir_setpos(IN FSW_FILE_DATA *File, IN UINT64 Position)
+{
+    if (Position == 0) {
+        File->shand.pos = 0;
+        return EFI_SUCCESS;
+    } else {
+        // directories can only rewind to the start
+        return EFI_UNSUPPORTED;
+    }
+}
+
+/**
+ * Get file or volume information. This function implements the GetInfo call
+ * for all file handles. Control is dispatched according to the type of information
+ * requested by the caller.
+ */
+
+EFI_STATUS fsw_efi_dnode_getinfo(IN FSW_FILE_DATA *File,
+                                 IN EFI_GUID *InformationType,
+                                 IN OUT UINTN *BufferSize,
+                                 OUT VOID *Buffer)
+{
+    EFI_STATUS            Status;
+    FSW_VOLUME_DATA       *Volume = (FSW_VOLUME_DATA *)File->shand.dnode->vol->host_data;
+    EFI_FILE_SYSTEM_INFO  *FSInfo;
+    UINTN                 RequiredSize;
+    struct fsw_volume_stat vsb;
+
+
+    if (CompareGuid(InformationType, &gEfiFileInfoGuid)) {
+#if DEBUG_LEVEL
+        Print(L"fsw_efi_dnode_getinfo: FILE_INFO\n");
+#endif
+
+        Status = fsw_efi_dnode_fill_FileInfo(Volume, File->shand.dnode, BufferSize, Buffer);
+
+    } else if (CompareGuid(InformationType, &gEfiFileSystemInfoGuid)) {
+#if DEBUG_LEVEL
+        Print(L"fsw_efi_dnode_getinfo: FILE_SYSTEM_INFO\n");
+#endif
+
+        // check buffer size
+        RequiredSize = SIZE_OF_EFI_FILE_SYSTEM_INFO + fsw_efi_strsize(&Volume->vol->label);
+        if (*BufferSize < RequiredSize) {
+            *BufferSize = RequiredSize;
+            return EFI_BUFFER_TOO_SMALL;
+        }
+
+        // fill structure
+        FSInfo = (EFI_FILE_SYSTEM_INFO *)Buffer;
+        FSInfo->Size        = RequiredSize;
+        FSInfo->ReadOnly    = TRUE;
+        FSInfo->BlockSize   = Volume->vol->log_blocksize;
+        fsw_efi_strcpy(FSInfo->VolumeLabel, &Volume->vol->label);
+
+        // get the missing info from the fs driver
+        ZeroMem(&vsb, sizeof(struct fsw_volume_stat));
+        Status = fsw_efi_map_status(fsw_volume_stat(Volume->vol, &vsb), Volume);
+        if (EFI_ERROR(Status))
+            return Status;
+        FSInfo->VolumeSize  = vsb.total_bytes;
+        FSInfo->FreeSpace   = vsb.free_bytes;
+
+        // prepare for return
+        *BufferSize = RequiredSize;
+        Status = EFI_SUCCESS;
+
+    } else if (CompareGuid(InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {
+#if DEBUG_LEVEL
+        Print(L"fsw_efi_dnode_getinfo: FILE_SYSTEM_VOLUME_LABEL\n");
+#endif
+
+        // check buffer size
+        RequiredSize = SIZE_OF_EFI_FILE_SYSTEM_VOLUME_LABEL_INFO + fsw_efi_strsize(&Volume->vol->label);
+        if (*BufferSize < RequiredSize) {
+            *BufferSize = RequiredSize;
+            return EFI_BUFFER_TOO_SMALL;
+        }
+
+        // copy volume label
+        fsw_efi_strcpy(((EFI_FILE_SYSTEM_VOLUME_LABEL_INFO *)Buffer)->VolumeLabel, &Volume->vol->label);
+
+        // prepare for return
+        *BufferSize = RequiredSize;
+        Status = EFI_SUCCESS;
+
+    } else {
+        Status = EFI_UNSUPPORTED;
+    }
+
+    return Status;
+}
+
+/**
+ * Time mapping callback for the fsw_dnode_stat call. This function converts
+ * a Posix style timestamp into an EFI_TIME structure and writes it to the
+ * appropriate member of the EFI_FILE_INFO structure that we're filling.
+ */
+
+static void fsw_efi_store_time_posix(struct fsw_dnode_stat *sb, int which, fsw_u32 posix_time)
+{
+    EFI_FILE_INFO       *FileInfo = (EFI_FILE_INFO *)sb->host_data;
+
+    if (which == FSW_DNODE_STAT_CTIME)
+        fsw_efi_decode_time(&FileInfo->CreateTime,       posix_time);
+    else if (which == FSW_DNODE_STAT_MTIME)
+        fsw_efi_decode_time(&FileInfo->ModificationTime, posix_time);
+    else if (which == FSW_DNODE_STAT_ATIME)
+        fsw_efi_decode_time(&FileInfo->LastAccessTime,   posix_time);
+}
+
+/**
+ * Mode mapping callback for the fsw_dnode_stat call. This function looks at
+ * the Posix mode passed by the file system driver and makes appropriate
+ * adjustments to the EFI_FILE_INFO structure that we're filling.
+ */
+
+static void fsw_efi_store_attr_posix(struct fsw_dnode_stat *sb, fsw_u16 posix_mode)
+{
+    EFI_FILE_INFO       *FileInfo = (EFI_FILE_INFO *)sb->host_data;
+
+    if ((posix_mode & S_IWUSR) == 0)
+        FileInfo->Attribute |= EFI_FILE_READ_ONLY;
+}
+
+/**
+ * Common function to fill an EFI_FILE_INFO with information about a dnode.
+ */
+
+EFI_STATUS fsw_efi_dnode_fill_FileInfo(IN FSW_VOLUME_DATA *Volume,
+                                       IN struct fsw_dnode *dno,
+                                       IN OUT UINTN *BufferSize,
+                                       OUT VOID *Buffer)
+{
+    EFI_STATUS          Status;
+    EFI_FILE_INFO       *FileInfo;
+    UINTN               RequiredSize;
+    struct fsw_dnode_stat sb;
+
+    // make sure the dnode has complete info
+    Status = fsw_efi_map_status(fsw_dnode_fill(dno), Volume);
+    if (EFI_ERROR(Status))
+        return Status;
+
+    // TODO: check/assert that the dno's name is in UTF16
+
+    // check buffer size
+    RequiredSize = SIZE_OF_EFI_FILE_INFO + fsw_efi_strsize(&dno->name);
+    if (*BufferSize < RequiredSize) {
+        // TODO: wind back the directory in this case
+
+#if DEBUG_LEVEL
+        Print(L"...BUFFER TOO SMALL\n");
+#endif
+        *BufferSize = RequiredSize;
+        return EFI_BUFFER_TOO_SMALL;
+    }
+
+    // fill structure
+    ZeroMem(Buffer, RequiredSize);
+    FileInfo = (EFI_FILE_INFO *)Buffer;
+    FileInfo->Size = RequiredSize;
+    FileInfo->FileSize          = dno->size;
+    FileInfo->Attribute         = 0;
+    if (dno->type == FSW_DNODE_TYPE_DIR)
+        FileInfo->Attribute    |= EFI_FILE_DIRECTORY;
+    fsw_efi_strcpy(FileInfo->FileName, &dno->name);
+
+    // get the missing info from the fs driver
+    ZeroMem(&sb, sizeof(struct fsw_dnode_stat));
+    sb.store_time_posix = fsw_efi_store_time_posix;
+    sb.store_attr_posix = fsw_efi_store_attr_posix;
+    sb.host_data = FileInfo;
+    Status = fsw_efi_map_status(fsw_dnode_stat(dno, &sb), Volume);
+    if (EFI_ERROR(Status))
+        return Status;
+    FileInfo->PhysicalSize      = sb.used_bytes;
+
+    // prepare for return
+    *BufferSize = RequiredSize;
+#if DEBUG_LEVEL
+    Print(L"...returning '%s'\n", FileInfo->FileName);
+#endif
+    return EFI_SUCCESS;
+}
+
+// EOF
diff --git a/ExtPkg/ExtPkgDxe/fsw_efi.h b/ExtPkg/ExtPkgDxe/fsw_efi.h
new file mode 100644
index 0000000..31e72da
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_efi.h
@@ -0,0 +1,132 @@ 
+/* $Id: fsw_efi.h 33540 2010-10-28 09:27:05Z vboxsync $ */
+/** @file
+ * fsw_efi.h - EFI host environment header.
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _FSW_EFI_H_
+#define _FSW_EFI_H_
+
+#include "fsw_core.h"
+#include "Protocol/SimpleFileSystem.h"
+#include "Protocol/DiskIo.h"
+#ifdef __MAKEWITH_GNUEFI
+#define CompareGuid(a, b) CompareGuid(a, b)==0
+#endif
+
+/**
+ * EFI Host: Private per-volume structure.
+ */
+
+# define GUID_NAME(x) gEfi ## x ## Guid
+
+# define EFI_FILE_HANDLE_REVISION EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION
+# define SIZE_OF_EFI_FILE_SYSTEM_VOLUME_LABEL_INFO  SIZE_OF_EFI_FILE_SYSTEM_VOLUME_LABEL
+# define EFI_FILE_SYSTEM_VOLUME_LABEL_INFO EFI_FILE_SYSTEM_VOLUME_LABEL
+# define EFI_SIGNATURE_32(a, b, c, d) SIGNATURE_32(a, b, c, d)
+# define DivU64x32(x,y,z) DivU64x32((x),(y))
+
+typedef struct {
+    UINT64                      Signature;      //!< Used to identify this structure
+
+    EFI_FILE_IO_INTERFACE       FileSystem;     //!< Published EFI protocol interface structure
+
+    EFI_HANDLE                  Handle;         //!< The device handle the protocol is attached to
+    EFI_DISK_IO                 *DiskIo;        //!< The Disk I/O protocol we use for disk access
+    UINT32                      MediaId;        //!< The media ID from the Block I/O protocol
+    EFI_STATUS                  LastIOStatus;   //!< Last status from Disk I/O
+
+    struct fsw_volume           *vol;           //!< FSW volume structure
+
+} FSW_VOLUME_DATA;
+
+
+#define SIGNATURE_16(A, B)        ((A) | (B << 8))
+#define SIGNATURE_32(A, B, C, D)  (SIGNATURE_16 (A, B) | (SIGNATURE_16 (C, D) << 16))
+# define EFI_SIGNATURE_32(a, b, c, d) SIGNATURE_32(a, b, c, d)
+/** Signature for the volume structure. */
+#define FSW_VOLUME_DATA_SIGNATURE  EFI_SIGNATURE_32 ('f', 's', 'w', 'V')
+/** Access macro for the volume structure. */
+#define FSW_VOLUME_FROM_FILE_SYSTEM(a)  CR (a, FSW_VOLUME_DATA, FileSystem, FSW_VOLUME_DATA_SIGNATURE)
+
+/**
+ * EFI Host: Private structure for a EFI_FILE interface.
+ */
+
+typedef struct {
+    UINT64                      Signature;      //!< Used to identify this structure
+
+    EFI_FILE                    FileHandle;     //!< Published EFI protocol interface structure
+
+    UINT64                       Type;           //!< File type used for dispatching
+    struct fsw_shandle          shand;          //!< FSW handle for this file
+
+} FSW_FILE_DATA;
+
+/** File type: regular file. */
+#define FSW_EFI_FILE_TYPE_FILE  (0)
+/** File type: directory. */
+#define FSW_EFI_FILE_TYPE_DIR   (1)
+
+/** Signature for the file handle structure. */
+#define FSW_FILE_DATA_SIGNATURE    EFI_SIGNATURE_32 ('f', 's', 'w', 'F')
+/** Access macro for the file handle structure. */
+#define FSW_FILE_FROM_FILE_HANDLE(a)  CR (a, FSW_FILE_DATA, FileHandle, FSW_FILE_DATA_SIGNATURE)
+
+
+//
+// Library functions
+//
+
+VOID fsw_efi_decode_time(OUT EFI_TIME *EfiTime, IN UINT32 UnixTime);
+
+UINTN fsw_efi_strsize(struct fsw_string *s);
+VOID fsw_efi_strcpy(CHAR16 *Dest, struct fsw_string *src);
+
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_efi_base.h b/ExtPkg/ExtPkgDxe/fsw_efi_base.h
new file mode 100644
index 0000000..f2968a6
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_efi_base.h
@@ -0,0 +1,89 @@ 
+/* $Id: fsw_efi_base.h 29125 2010-05-06 09:43:05Z vboxsync $ */
+/** @file
+ * fsw_efi_base.h - Base definitions for the EFI host environment.
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _FSW_EFI_BASE_H_
+#define _FSW_EFI_BASE_H_
+
+#define FSW_LITTLE_ENDIAN (1)
+
+// types, reuse EFI types
+typedef INT8    fsw_s8;
+typedef UINT8   fsw_u8;
+typedef INT16   fsw_s16;
+typedef UINT16  fsw_u16;
+typedef INT32   fsw_s32;
+typedef UINT32  fsw_u32;
+typedef INT64   fsw_s64;
+typedef UINT64  fsw_u64;
+
+
+// allocation functions
+
+#define fsw_alloc(size, ptrptr) (((*(ptrptr) = AllocatePool(size)) == NULL) ? FSW_OUT_OF_MEMORY : FSW_SUCCESS)
+#define fsw_free(ptr) FreePool(ptr)
+
+// memory functions
+
+#define fsw_memzero(dest,size) ZeroMem(dest,size)
+#define fsw_memcpy(dest,src,size) CopyMem(dest,src,size)
+#define fsw_memeq(p1,p2,size) (CompareMem(p1,p2,size) == 0)
+
+// message printing
+
+#define FSW_MSGSTR(s) L##s
+#define FSW_MSGFUNC Print
+
+// 64-bit hooks
+
+#define FSW_U64_SHR(val,shiftbits) RShiftU64((val), (shiftbits))
+#define FSW_U64_DIV(val,divisor) DivU64x32((val), (divisor), NULL)
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_efi_lib.c b/ExtPkg/ExtPkgDxe/fsw_efi_lib.c
new file mode 100644
index 0000000..9c97843
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_efi_lib.c
@@ -0,0 +1,159 @@ 
+/* $Id: fsw_efi_lib.c 29125 2010-05-06 09:43:05Z vboxsync $ */
+/** @file
+ * fsw_efi_lib.c - EFI host environment library functions.
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fsw_efi.h"
+
+//
+// time conversion
+//
+// Adopted from public domain code in FreeBSD libc.
+//
+
+#define SECSPERMIN      60
+#define MINSPERHOUR     60
+#define HOURSPERDAY     24
+#define DAYSPERWEEK     7
+#define DAYSPERNYEAR    365
+#define DAYSPERLYEAR    366
+#define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
+#define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
+#define MONSPERYEAR     12
+
+#define EPOCH_YEAR      1970
+#define EPOCH_WDAY      TM_THURSDAY
+
+#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
+#define LEAPS_THRU_END_OF(y)    ((y) / 4 - (y) / 100 + (y) / 400)
+
+static const int mon_lengths[2][MONSPERYEAR] = {
+    { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+    { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
+};
+static const int year_lengths[2] = {
+    DAYSPERNYEAR, DAYSPERLYEAR
+};
+
+VOID fsw_efi_decode_time(OUT EFI_TIME *EfiTime, IN UINT32 UnixTime)
+{
+    long        days, rem;
+    int         y, newy, yleap;
+    const int   *ip;
+
+    ZeroMem(EfiTime, sizeof(EFI_TIME));
+
+    days = UnixTime / SECSPERDAY;
+    rem = UnixTime % SECSPERDAY;
+
+    EfiTime->Hour = (UINT8) (rem / SECSPERHOUR);
+    rem = rem % SECSPERHOUR;
+    EfiTime->Minute = (UINT8) (rem / SECSPERMIN);
+    EfiTime->Second = (UINT8) (rem % SECSPERMIN);
+
+    y = EPOCH_YEAR;
+    while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
+        newy = y + days / DAYSPERNYEAR;
+        if (days < 0)
+            --newy;
+        days -= (newy - y) * DAYSPERNYEAR +
+            LEAPS_THRU_END_OF(newy - 1) -
+            LEAPS_THRU_END_OF(y - 1);
+        y = newy;
+    }
+    EfiTime->Year = (UINT16)y;
+    ip = mon_lengths[yleap];
+    for (EfiTime->Month = 0; days >= (long) ip[EfiTime->Month]; ++(EfiTime->Month))
+        days = days - (long) ip[EfiTime->Month];
+    EfiTime->Month++;  // adjust range to EFI conventions
+    EfiTime->Day = (UINT8) (days + 1);
+}
+
+//
+// String functions, used for file and volume info
+//
+
+UINTN fsw_efi_strsize(struct fsw_string *s)
+{
+    if (s->type == FSW_STRING_TYPE_EMPTY)
+        return sizeof(CHAR16);
+    return (s->len + 1) * sizeof(CHAR16);
+}
+
+VOID fsw_efi_strcpy(CHAR16 *Dest, struct fsw_string *src)
+{
+    if (src->type == FSW_STRING_TYPE_EMPTY) {
+        Dest[0] = 0;
+    } else if (src->type == FSW_STRING_TYPE_UTF16) {
+        CopyMem(Dest, src->data, src->size);
+        Dest[src->len] = 0;
+    } else {
+        // TODO: coerce, recurse
+        Dest[0] = 0;
+    }
+}
+
+int fsw_streq_ISO88591_UTF16(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u8 *p1 = (fsw_u8 *)s1data;
+    fsw_u16 *p2 = (fsw_u16 *)s2data;
+
+    for (i = 0; i<len; i++)
+    {
+        if (fsw_to_lower(p1[i]) != fsw_to_lower(p2[i]))
+        {
+            return 0;
+        }
+    }
+
+    return 1;
+}
+
+// EOF
diff --git a/ExtPkg/ExtPkgDxe/fsw_ext2.c b/ExtPkg/ExtPkgDxe/fsw_ext2.c
new file mode 100644
index 0000000..6f882c2
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_ext2.c
@@ -0,0 +1,553 @@ 
+/**
+ * \file fsw_ext2.c
+ * ext2 file system driver code.
+ */
+
+/*-
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include "fsw_ext2.h"
+
+
+// functions
+
+static fsw_status_t fsw_ext2_volume_mount(struct fsw_ext2_volume *vol);
+static void         fsw_ext2_volume_free(struct fsw_ext2_volume *vol);
+static fsw_status_t fsw_ext2_volume_stat(struct fsw_ext2_volume *vol, struct fsw_volume_stat *sb);
+
+static fsw_status_t fsw_ext2_dnode_fill(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno);
+static void         fsw_ext2_dnode_free(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno);
+static fsw_status_t fsw_ext2_dnode_stat(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                        struct fsw_dnode_stat *sb);
+static fsw_status_t fsw_ext2_get_extent(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                        struct fsw_extent *extent);
+
+static fsw_status_t fsw_ext2_dir_lookup(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                        struct fsw_string *lookup_name, struct fsw_ext2_dnode **child_dno);
+static fsw_status_t fsw_ext2_dir_read(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                      struct fsw_shandle *shand, struct fsw_ext2_dnode **child_dno);
+static fsw_status_t fsw_ext2_read_dentry(struct fsw_shandle *shand, struct ext2_dir_entry *entry);
+
+static fsw_status_t fsw_ext2_readlink(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                      struct fsw_string *link);
+
+//
+// Dispatch Table
+//
+
+struct fsw_fstype_table   FSW_FSTYPE_TABLE_NAME(ext2) = {
+    { FSW_STRING_TYPE_ISO88591, 4, 4, "ext2" },
+    sizeof(struct fsw_ext2_volume),
+    sizeof(struct fsw_ext2_dnode),
+
+    fsw_ext2_volume_mount,
+    fsw_ext2_volume_free,
+    fsw_ext2_volume_stat,
+    fsw_ext2_dnode_fill,
+    fsw_ext2_dnode_free,
+    fsw_ext2_dnode_stat,
+    fsw_ext2_get_extent,
+    fsw_ext2_dir_lookup,
+    fsw_ext2_dir_read,
+    fsw_ext2_readlink,
+};
+
+/**
+ * Mount an ext2 volume. Reads the superblock and constructs the
+ * root directory dnode.
+ */
+
+static fsw_status_t fsw_ext2_volume_mount(struct fsw_ext2_volume *vol)
+{
+    fsw_status_t    status;
+    void            *buffer;
+    fsw_u32         blocksize;
+    fsw_u32         groupcnt, groupno, gdesc_per_block, gdesc_bno, gdesc_index;
+    struct ext2_group_desc *gdesc;
+    int             i;
+    struct fsw_string s;
+
+    // allocate memory to keep the superblock around
+    status = fsw_alloc(sizeof(struct ext2_super_block), &vol->sb);
+    if (status)
+        return status;
+
+    // read the superblock into its buffer
+    fsw_set_blocksize(vol, EXT2_SUPERBLOCK_BLOCKSIZE, EXT2_SUPERBLOCK_BLOCKSIZE);
+    status = fsw_block_get(vol, EXT2_SUPERBLOCK_BLOCKNO, 0, &buffer);
+    if (status)
+        return status;
+    fsw_memcpy(vol->sb, buffer, sizeof(struct ext2_super_block));
+    fsw_block_release(vol, EXT2_SUPERBLOCK_BLOCKNO, buffer);
+
+    // check the superblock
+    if (vol->sb->s_magic != EXT2_SUPER_MAGIC)
+        return FSW_UNSUPPORTED;
+    if (vol->sb->s_rev_level != EXT2_GOOD_OLD_REV &&
+        vol->sb->s_rev_level != EXT2_DYNAMIC_REV)
+        return FSW_UNSUPPORTED;
+    if (vol->sb->s_rev_level == EXT2_DYNAMIC_REV &&
+        (vol->sb->s_feature_incompat & ~(EXT2_FEATURE_INCOMPAT_FILETYPE | EXT3_FEATURE_INCOMPAT_RECOVER)))
+        return FSW_UNSUPPORTED;
+
+    // set real blocksize
+    blocksize = EXT2_BLOCK_SIZE(vol->sb);
+    fsw_set_blocksize(vol, blocksize, blocksize);
+
+    // get other info from superblock
+    vol->ind_bcnt = EXT2_ADDR_PER_BLOCK(vol->sb);
+    vol->dind_bcnt = vol->ind_bcnt * vol->ind_bcnt;
+    vol->inode_size = EXT2_INODE_SIZE(vol->sb);
+
+    for (i = 0; i < 16; i++)
+        if (vol->sb->s_volume_name[i] == 0)
+            break;
+    s.type = FSW_STRING_TYPE_ISO88591;
+    s.size = s.len = i;
+    s.data = vol->sb->s_volume_name;
+    status = fsw_strdup_coerce(&vol->g.label, vol->g.host_string_type, &s);
+    if (status)
+        return status;
+
+    // read the group descriptors to get inode table offsets
+    groupcnt = ((vol->sb->s_inodes_count - 2) / vol->sb->s_inodes_per_group) + 1;
+    gdesc_per_block = (vol->g.phys_blocksize / sizeof(struct ext2_group_desc));
+
+    status = fsw_alloc(sizeof(fsw_u32) * groupcnt, &vol->inotab_bno);
+    if (status)
+        return status;
+    for (groupno = 0; groupno < groupcnt; groupno++) {
+        // get the block group descriptor
+        gdesc_bno = (vol->sb->s_first_data_block + 1) + groupno / gdesc_per_block;
+        gdesc_index = groupno % gdesc_per_block;
+        status = fsw_block_get(vol, gdesc_bno, 1, (void **)&buffer);
+        if (status)
+            return status;
+        gdesc = ((struct ext2_group_desc *)(buffer)) + gdesc_index;
+        vol->inotab_bno[groupno] = gdesc->bg_inode_table;
+        fsw_block_release(vol, gdesc_bno, buffer);
+    }
+
+    // setup the root dnode
+    status = fsw_dnode_create_root(vol, EXT2_ROOT_INO, &vol->g.root);
+    if (status)
+        return status;
+
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext2_volume_mount: success, blocksize %d\n"), blocksize));
+    AsciiPrint("fsw_ext2_volume_mount: success, blocksize %d\n", blocksize);
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Free the volume data structure. Called by the core after an unmount or after
+ * an unsuccessful mount to release the memory used by the file system type specific
+ * part of the volume structure.
+ */
+
+static void fsw_ext2_volume_free(struct fsw_ext2_volume *vol)
+{
+    if (vol->sb)
+        fsw_free(vol->sb);
+    if (vol->inotab_bno)
+        fsw_free(vol->inotab_bno);
+}
+
+/**
+ * Get in-depth information on a volume.
+ */
+
+static fsw_status_t fsw_ext2_volume_stat(struct fsw_ext2_volume *vol, struct fsw_volume_stat *sb)
+{
+    sb->total_bytes = (fsw_u64)vol->sb->s_blocks_count      * vol->g.log_blocksize;
+    sb->free_bytes  = (fsw_u64)vol->sb->s_free_blocks_count * vol->g.log_blocksize;
+    return FSW_SUCCESS;
+}
+
+/**
+ * Get full information on a dnode from disk. This function is called by the core
+ * whenever it needs to access fields in the dnode structure that may not
+ * be filled immediately upon creation of the dnode. In the case of ext2, we
+ * delay fetching of the inode structure until dnode_fill is called. The size and
+ * type fields are invalid until this function has been called.
+ */
+
+static fsw_status_t fsw_ext2_dnode_fill(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno)
+{
+    fsw_status_t    status;
+    fsw_u32         groupno, ino_in_group, ino_bno, ino_index;
+    fsw_u8          *buffer;
+
+    if (dno->raw)
+        return FSW_SUCCESS;
+
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext2_dnode_fill: inode %d\n"), dno->g.dnode_id));
+
+    // read the inode block
+    groupno = (dno->g.dnode_id - 1) / vol->sb->s_inodes_per_group;
+    ino_in_group = (dno->g.dnode_id - 1) % vol->sb->s_inodes_per_group;
+    ino_bno = vol->inotab_bno[groupno] +
+        ino_in_group / (vol->g.phys_blocksize / vol->inode_size);
+    ino_index = ino_in_group % (vol->g.phys_blocksize / vol->inode_size);
+    status = fsw_block_get(vol, ino_bno, 2, (void **)&buffer);
+    if (status)
+        return status;
+
+    // keep our inode around
+    status = fsw_memdup((void **)&dno->raw, buffer + ino_index * vol->inode_size, vol->inode_size);
+    fsw_block_release(vol, ino_bno, buffer);
+    if (status)
+        return status;
+
+    // get info from the inode
+    dno->g.size = dno->raw->i_size;
+    // TODO: check docs for 64-bit sized files
+    if (S_ISREG(dno->raw->i_mode))
+        dno->g.type = FSW_DNODE_TYPE_FILE;
+    else if (S_ISDIR(dno->raw->i_mode))
+        dno->g.type = FSW_DNODE_TYPE_DIR;
+    else if (S_ISLNK(dno->raw->i_mode))
+        dno->g.type = FSW_DNODE_TYPE_SYMLINK;
+    else
+        dno->g.type = FSW_DNODE_TYPE_SPECIAL;
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Free the dnode data structure. Called by the core when deallocating a dnode
+ * structure to release the memory used by the file system type specific part
+ * of the dnode structure.
+ */
+
+static void fsw_ext2_dnode_free(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno)
+{
+    if (dno->raw)
+        fsw_free(dno->raw);
+}
+
+/**
+ * Get in-depth information on a dnode. The core makes sure that fsw_ext2_dnode_fill
+ * has been called on the dnode before this function is called. Note that some
+ * data is not directly stored into the structure, but passed to a host-specific
+ * callback that converts it to the host-specific format.
+ */
+
+static fsw_status_t fsw_ext2_dnode_stat(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                        struct fsw_dnode_stat *sb)
+{
+    sb->used_bytes = dno->raw->i_blocks * 512;   // very, very strange...
+    sb->store_time_posix(sb, FSW_DNODE_STAT_CTIME, dno->raw->i_ctime);
+    sb->store_time_posix(sb, FSW_DNODE_STAT_ATIME, dno->raw->i_atime);
+    sb->store_time_posix(sb, FSW_DNODE_STAT_MTIME, dno->raw->i_mtime);
+    sb->store_attr_posix(sb, dno->raw->i_mode);
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Retrieve file data mapping information. This function is called by the core when
+ * fsw_shandle_read needs to know where on the disk the required piece of the file's
+ * data can be found. The core makes sure that fsw_ext2_dnode_fill has been called
+ * on the dnode before. Our task here is to get the physical disk block number for
+ * the requested logical block number.
+ *
+ * The ext2 file system does not use extents, but stores a list of block numbers
+ * using the usual direct, indirect, double-indirect, triple-indirect scheme. To
+ * optimize access, this function checks if the following file blocks are mapped
+ * to consecutive disk blocks and returns a combined extent if possible.
+ */
+
+static fsw_status_t fsw_ext2_get_extent(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                        struct fsw_extent *extent)
+{
+    fsw_status_t    status;
+    fsw_u32         bno, release_bno, buf_bcnt, file_bcnt;
+    fsw_u32         *buffer;
+    int             path[5], i;
+
+    // Preconditions: The caller has checked that the requested logical block
+    //  is within the file's size. The dnode has complete information, i.e.
+    //  fsw_ext2_dnode_read_info was called successfully on it.
+
+    extent->type = FSW_EXTENT_TYPE_PHYSBLOCK;
+    extent->log_count = 1;
+    bno = extent->log_start;
+
+    // try direct block pointers in the inode
+    if (bno < EXT2_NDIR_BLOCKS) {
+        path[0] = bno;
+        path[1] = -1;
+    } else {
+        bno -= EXT2_NDIR_BLOCKS;
+
+        // try indirect block
+        if (bno < vol->ind_bcnt) {
+            path[0] = EXT2_IND_BLOCK;
+            path[1] = bno;
+            path[2] = -1;
+        } else {
+            bno -= vol->ind_bcnt;
+
+            // try double-indirect block
+            if (bno < vol->dind_bcnt) {
+                path[0] = EXT2_DIND_BLOCK;
+                path[1] = bno / vol->ind_bcnt;
+                path[2] = bno % vol->ind_bcnt;
+                path[3] = -1;
+            } else {
+                bno -= vol->dind_bcnt;
+
+                // use the triple-indirect block
+                path[0] = EXT2_TIND_BLOCK;
+                path[1] = bno / vol->dind_bcnt;
+                path[2] = (bno / vol->ind_bcnt) % vol->ind_bcnt;
+                path[3] = bno % vol->ind_bcnt;
+                path[4] = -1;
+            }
+        }
+    }
+
+    // follow the indirection path
+    buffer = dno->raw->i_block;
+    buf_bcnt = EXT2_NDIR_BLOCKS;
+    release_bno = 0;
+    for (i = 0; ; i++) {
+        bno = buffer[path[i]];
+        if (bno == 0) {
+            extent->type = FSW_EXTENT_TYPE_SPARSE;
+            if (release_bno)
+                fsw_block_release(vol, release_bno, buffer);
+            return FSW_SUCCESS;
+        }
+        if (path[i+1] < 0)
+            break;
+
+        if (release_bno)
+            fsw_block_release(vol, release_bno, buffer);
+        status = fsw_block_get(vol, bno, 1, (void **)&buffer);
+        if (status)
+            return status;
+        release_bno = bno;
+        buf_bcnt = vol->ind_bcnt;
+    }
+    extent->phys_start = bno;
+
+    // check if the following blocks can be aggregated into one extent
+    file_bcnt = (fsw_u32)((dno->g.size + vol->g.log_blocksize - 1) & (vol->g.log_blocksize - 1));
+    while (path[i]           + extent->log_count < buf_bcnt &&    // indirect block has more block pointers
+           extent->log_start + extent->log_count < file_bcnt) {   // file has more blocks
+        if (buffer[path[i] + extent->log_count] == buffer[path[i] + extent->log_count - 1] + 1)
+            extent->log_count++;
+        else
+            break;
+    }
+
+    if (release_bno)
+        fsw_block_release(vol, release_bno, buffer);
+    return FSW_SUCCESS;
+}
+
+/**
+ * Lookup a directory's child dnode by name. This function is called on a directory
+ * to retrieve the directory entry with the given name. A dnode is constructed for
+ * this entry and returned. The core makes sure that fsw_ext2_dnode_fill has been called
+ * and the dnode is actually a directory.
+ */
+
+static fsw_status_t fsw_ext2_dir_lookup(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                        struct fsw_string *lookup_name, struct fsw_ext2_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_shandle shand;
+    fsw_u32         child_ino;
+    struct ext2_dir_entry entry;
+    struct fsw_string entry_name;
+
+    // Preconditions: The caller has checked that dno is a directory node.
+
+    entry_name.type = FSW_STRING_TYPE_ISO88591;
+
+    // setup handle to read the directory
+    status = fsw_shandle_open(dno, &shand);
+    if (status)
+        return status;
+
+    // scan the directory for the file
+    child_ino = 0;
+    while (child_ino == 0) {
+        // read next entry
+        status = fsw_ext2_read_dentry(&shand, &entry);
+        if (status)
+            goto errorexit;
+        if (entry.inode == 0) {
+            // end of directory reached
+            status = FSW_NOT_FOUND;
+            goto errorexit;
+        }
+
+        // compare name
+        entry_name.len = entry_name.size = entry.name_len;
+        entry_name.data = entry.name;
+        if (fsw_streq(lookup_name, &entry_name)) {
+            child_ino = entry.inode;
+            break;
+        }
+    }
+
+    // setup a dnode for the child item
+    status = fsw_dnode_create(dno, child_ino, FSW_DNODE_TYPE_UNKNOWN, &entry_name, child_dno_out);
+
+errorexit:
+    fsw_shandle_close(&shand);
+    return status;
+}
+
+/**
+ * Get the next directory entry when reading a directory. This function is called during
+ * directory iteration to retrieve the next directory entry. A dnode is constructed for
+ * the entry and returned. The core makes sure that fsw_ext2_dnode_fill has been called
+ * and the dnode is actually a directory. The shandle provided by the caller is used to
+ * record the position in the directory between calls.
+ */
+
+static fsw_status_t fsw_ext2_dir_read(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                      struct fsw_shandle *shand, struct fsw_ext2_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+    struct ext2_dir_entry entry;
+    struct fsw_string entry_name;
+
+    // Preconditions: The caller has checked that dno is a directory node. The caller
+    //  has opened a storage handle to the directory's storage and keeps it around between
+    //  calls.
+
+    while (1) {
+        // read next entry
+        status = fsw_ext2_read_dentry(shand, &entry);
+        if (status)
+            return status;
+        if (entry.inode == 0)   // end of directory
+            return FSW_NOT_FOUND;
+
+        // skip . and ..
+        if ((entry.name_len == 1 && entry.name[0] == '.') ||
+            (entry.name_len == 2 && entry.name[0] == '.' && entry.name[1] == '.'))
+            continue;
+        break;
+    }
+
+    // setup name
+    entry_name.type = FSW_STRING_TYPE_ISO88591;
+    entry_name.len = entry_name.size = entry.name_len;
+    entry_name.data = entry.name;
+
+    // setup a dnode for the child item
+    status = fsw_dnode_create(dno, entry.inode, FSW_DNODE_TYPE_UNKNOWN, &entry_name, child_dno_out);
+
+    return status;
+}
+
+/**
+ * Read a directory entry from the directory's raw data. This internal function is used
+ * to read a raw ext2 directory entry into memory. The shandle's position pointer is adjusted
+ * to point to the next entry.
+ */
+
+static fsw_status_t fsw_ext2_read_dentry(struct fsw_shandle *shand, struct ext2_dir_entry *entry)
+{
+    fsw_status_t    status;
+    fsw_u32         buffer_size;
+
+    while (1) {
+        // read dir_entry header (fixed length)
+        buffer_size = 8;
+        status = fsw_shandle_read(shand, &buffer_size, entry);
+        if (status)
+            return status;
+
+        if (buffer_size < 8 || entry->rec_len == 0) {
+            // end of directory reached
+            entry->inode = 0;
+            return FSW_SUCCESS;
+        }
+        if (entry->rec_len < 8)
+            return FSW_VOLUME_CORRUPTED;
+        if (entry->inode != 0) {
+            // this entry is used
+            if (entry->rec_len < 8 + entry->name_len)
+                return FSW_VOLUME_CORRUPTED;
+            break;
+        }
+
+        // valid, but unused entry, skip it
+        shand->pos += entry->rec_len - 8;
+    }
+
+    // read file name (variable length)
+    buffer_size = entry->name_len;
+    status = fsw_shandle_read(shand, &buffer_size, entry->name);
+    if (status)
+        return status;
+    if (buffer_size < entry->name_len)
+        return FSW_VOLUME_CORRUPTED;
+
+    // skip any remaining padding
+    shand->pos += entry->rec_len - (8 + entry->name_len);
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Get the target path of a symbolic link. This function is called when a symbolic
+ * link needs to be resolved. The core makes sure that the fsw_ext2_dnode_fill has been
+ * called on the dnode and that it really is a symlink.
+ *
+ * For ext2, the target path can be stored inline in the inode structure (in the space
+ * otherwise occupied by the block pointers) or in the inode's data. There is no flag
+ * indicating this, only the number of blocks entry (i_blocks) can be used as an
+ * indication. The check used here comes from the Linux kernel.
+ */
+
+static fsw_status_t fsw_ext2_readlink(struct fsw_ext2_volume *vol, struct fsw_ext2_dnode *dno,
+                                      struct fsw_string *link_target)
+{
+    fsw_status_t    status;
+    int             ea_blocks;
+    struct fsw_string s;
+
+    if (dno->g.size > FSW_PATH_MAX)
+        return FSW_VOLUME_CORRUPTED;
+
+    ea_blocks = dno->raw->i_file_acl ? (vol->g.log_blocksize >> 9) : 0;
+
+    if (dno->raw->i_blocks - ea_blocks == 0) {
+        // "fast" symlink, path is stored inside the inode
+        s.type = FSW_STRING_TYPE_ISO88591;
+        s.size = s.len = (int)dno->g.size;
+        s.data = dno->raw->i_block;
+        status = fsw_strdup_coerce(link_target, vol->g.host_string_type, &s);
+    } else {
+        // "slow" symlink, path is stored in normal inode data
+        status = fsw_dnode_readlink_data(dno, link_target);
+    }
+
+    return status;
+}
+
+// EOF
diff --git a/ExtPkg/ExtPkgDxe/fsw_ext2.h b/ExtPkg/ExtPkgDxe/fsw_ext2.h
new file mode 100644
index 0000000..13b4caa
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_ext2.h
@@ -0,0 +1,65 @@ 
+/**
+ * \file fsw_ext2.h
+ * ext2 file system driver header.
+ */
+
+/*-
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef _FSW_EXT2_H_
+#define _FSW_EXT2_H_
+
+#define VOLSTRUCTNAME fsw_ext2_volume
+#define DNODESTRUCTNAME fsw_ext2_dnode
+#include "fsw_core.h"
+
+#include "fsw_ext2_disk.h"
+
+
+//! Block size to be used when reading the ext2 superblock.
+#define EXT2_SUPERBLOCK_BLOCKSIZE  1024
+//! Block number where the (master copy of the) ext2 superblock resides.
+#define EXT2_SUPERBLOCK_BLOCKNO       1
+
+
+/**
+ * ext2: Volume structure with ext2-specific data.
+ */
+
+struct fsw_ext2_volume {
+    struct fsw_volume g;            //!< Generic volume structure
+    
+    struct ext2_super_block *sb;    //!< Full raw ext2 superblock structure
+    fsw_u32     *inotab_bno;        //!< Block numbers of the inode tables
+    fsw_u32     ind_bcnt;           //!< Number of blocks addressable through an indirect block
+    fsw_u32     dind_bcnt;          //!< Number of blocks addressable through a double-indirect block
+    fsw_u32     inode_size;         //!< Size of inode structure in bytes
+};
+
+/**
+ * ext2: Dnode structure with ext2-specific data.
+ */
+
+struct fsw_ext2_dnode {
+    struct fsw_dnode g;             //!< Generic dnode structure
+    
+    struct ext2_inode *raw;         //!< Full raw inode structure
+};
+
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_ext2_disk.h b/ExtPkg/ExtPkgDxe/fsw_ext2_disk.h
new file mode 100644
index 0000000..c89020b
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_ext2_disk.h
@@ -0,0 +1,356 @@ 
+/**
+ * \file fsw_ext2_disk.h
+ * ext2 file system on-disk structures.
+ */
+
+/*-
+ * Copyright (c) 2006 Christoph Pfisterer
+ * Portions Copyright (c) 1991-2006 by various Linux kernel contributors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef _FSW_EXT2_DISK_H_
+#define _FSW_EXT2_DISK_H_
+
+// types
+
+typedef fsw_s8  __s8;
+typedef fsw_u8  __u8;
+typedef fsw_s16 __s16;
+typedef fsw_u16 __u16;
+typedef fsw_s32 __s32;
+typedef fsw_u32 __u32;
+typedef fsw_s64 __s64;
+typedef fsw_u64 __u64;
+
+typedef __u16   __le16;
+typedef __u32   __le32;
+typedef __u64   __le64;
+
+//
+// from Linux kernel, include/linux/ext2_fs.h
+//
+
+/*
+ * Special inode numbers
+ */
+#define EXT2_BAD_INO             1      /* Bad blocks inode */
+#define EXT2_ROOT_INO            2      /* Root inode */
+#define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
+#define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
+
+/*
+ * The second extended file system magic number
+ */
+#define EXT2_SUPER_MAGIC        0xEF53
+
+/*
+ * Macro-instructions used to manage several block sizes
+ */
+#define EXT2_MIN_BLOCK_SIZE             1024
+#define EXT2_MAX_BLOCK_SIZE             4096
+#define EXT2_MIN_BLOCK_LOG_SIZE           10
+#define EXT2_BLOCK_SIZE(s)              (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
+#define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
+#define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_log_block_size + 10)
+#define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
+                                 EXT2_GOOD_OLD_INODE_SIZE : \
+                                 (s)->s_inode_size)
+#define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
+                                 EXT2_GOOD_OLD_FIRST_INO : \
+                                 (s)->s_first_ino)
+
+/*
+ * Structure of a blocks group descriptor
+ */
+struct ext2_group_desc
+{
+    __le32  bg_block_bitmap;        /* Blocks bitmap block */
+    __le32  bg_inode_bitmap;        /* Inodes bitmap block */
+    __le32  bg_inode_table;         /* Inodes table block */
+    __le16  bg_free_blocks_count;   /* Free blocks count */
+    __le16  bg_free_inodes_count;   /* Free inodes count */
+    __le16  bg_used_dirs_count;     /* Directories count */
+    __le16  bg_pad;
+    __le32  bg_reserved[3];
+};
+
+/*
+ * Macro-instructions used to manage group descriptors
+ */
+#define EXT2_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
+#define EXT2_DESC_PER_BLOCK(s)         (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
+#define EXT2_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
+
+/*
+ * Constants relative to the data blocks
+ */
+#define EXT2_NDIR_BLOCKS                12
+#define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
+#define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
+#define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
+#define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
+
+/*
+ * Inode flags
+ */
+#define EXT2_SECRM_FL                   0x00000001 /* Secure deletion */
+#define EXT2_UNRM_FL                    0x00000002 /* Undelete */
+#define EXT2_COMPR_FL                   0x00000004 /* Compress file */
+#define EXT2_SYNC_FL                    0x00000008 /* Synchronous updates */
+#define EXT2_IMMUTABLE_FL               0x00000010 /* Immutable file */
+#define EXT2_APPEND_FL                  0x00000020 /* writes to file may only append */
+#define EXT2_NODUMP_FL                  0x00000040 /* do not dump file */
+#define EXT2_NOATIME_FL                 0x00000080 /* do not update atime */
+/* Reserved for compression usage... */
+#define EXT2_DIRTY_FL                   0x00000100
+#define EXT2_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
+#define EXT2_NOCOMP_FL                  0x00000400 /* Don't compress */
+#define EXT2_ECOMPR_FL                  0x00000800 /* Compression error */
+/* End compression flags --- maybe not all used */      
+#define EXT2_BTREE_FL                   0x00001000 /* btree format dir */
+#define EXT2_INDEX_FL                   0x00001000 /* hash-indexed directory */
+#define EXT2_IMAGIC_FL                  0x00002000 /* AFS directory */
+#define EXT2_JOURNAL_DATA_FL            0x00004000 /* Reserved for ext3 */
+#define EXT2_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
+#define EXT2_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
+#define EXT2_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
+#define EXT2_RESERVED_FL                0x80000000 /* reserved for ext2 lib */
+
+#define EXT2_FL_USER_VISIBLE            0x0003DFFF /* User visible flags */
+#define EXT2_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */
+
+/*
+ * Structure of an inode on the disk
+ */
+struct ext2_inode {
+    __le16  i_mode;         /* 0: File mode */
+    __le16  i_uid;          /* 2: Low 16 bits of Owner Uid */
+    __le32  i_size;         /* 4: Size in bytes */
+    __le32  i_atime;        /* 8: Access time */
+    __le32  i_ctime;        /* 12: Creation time */
+    __le32  i_mtime;        /* 16: Modification time */
+    __le32  i_dtime;        /* 20: Deletion Time */
+    __le16  i_gid;          /* 24: Low 16 bits of Group Id */
+    __le16  i_links_count;  /* 26: Links count */
+    __le32  i_blocks;       /* 28: Blocks count */
+    __le32  i_flags;        /* 32: File flags */
+    union {
+        struct {
+            __le32  l_i_reserved1;
+        } linux1;
+        struct {
+            __le32  h_i_translator;
+        } hurd1;
+        struct {
+            __le32  m_i_reserved1;
+        } masix1;
+    } osd1;                         /* 36: OS dependent 1 */
+    __le32  i_block[EXT2_N_BLOCKS];/* 40: Pointers to blocks */
+    __le32  i_generation;   /* 100: File version (for NFS) */
+    __le32  i_file_acl;     /* 104: File ACL */
+    __le32  i_dir_acl;      /* 108: Directory ACL */
+    __le32  i_faddr;        /* 112: Fragment address */
+    union {
+        struct {
+            __u8    l_i_frag;       /* 116: Fragment number */
+            __u8    l_i_fsize;      /* 117: Fragment size */
+            __u16   i_pad1;
+            __le16  l_i_uid_high;   /* 120: these 2 fields    */
+            __le16  l_i_gid_high;   /* 122: were reserved2[0] */
+            __u32   l_i_reserved2;
+        } linux2;
+        struct {
+            __u8    h_i_frag;       /* Fragment number */
+            __u8    h_i_fsize;      /* Fragment size */
+            __le16  h_i_mode_high;
+            __le16  h_i_uid_high;
+            __le16  h_i_gid_high;
+            __le32  h_i_author;
+        } hurd2;
+        struct {
+            __u8    m_i_frag;       /* Fragment number */
+            __u8    m_i_fsize;      /* Fragment size */
+            __u16   m_pad1;
+            __u32   m_i_reserved2[2];
+        } masix2;
+    } osd2;                         /* OS dependent 2 */
+};
+
+#define i_size_high     i_dir_acl
+
+/*
+ * Structure of the super block
+ */
+struct ext2_super_block {
+    __le32  s_inodes_count;         /* Inodes count */
+    __le32  s_blocks_count;         /* Blocks count */
+    __le32  s_r_blocks_count;       /* Reserved blocks count */
+    __le32  s_free_blocks_count;    /* Free blocks count */
+    __le32  s_free_inodes_count;    /* Free inodes count */
+    __le32  s_first_data_block;     /* First Data Block */
+    __le32  s_log_block_size;       /* Block size */
+    __le32  s_log_frag_size;        /* Fragment size */
+    __le32  s_blocks_per_group;     /* # Blocks per group */
+    __le32  s_frags_per_group;      /* # Fragments per group */
+    __le32  s_inodes_per_group;     /* # Inodes per group */
+    __le32  s_mtime;                /* Mount time */
+    __le32  s_wtime;                /* Write time */
+    __le16  s_mnt_count;            /* Mount count */
+    __le16  s_max_mnt_count;        /* Maximal mount count */
+    __le16  s_magic;                /* Magic signature */
+    __le16  s_state;                /* File system state */
+    __le16  s_errors;               /* Behaviour when detecting errors */
+    __le16  s_minor_rev_level;      /* minor revision level */
+    __le32  s_lastcheck;            /* time of last check */
+    __le32  s_checkinterval;        /* max. time between checks */
+    __le32  s_creator_os;           /* OS */
+    __le32  s_rev_level;            /* Revision level */
+    __le16  s_def_resuid;           /* Default uid for reserved blocks */
+    __le16  s_def_resgid;           /* Default gid for reserved blocks */
+    /*
+     * These fields are for EXT2_DYNAMIC_REV superblocks only.
+     *
+     * Note: the difference between the compatible feature set and
+     * the incompatible feature set is that if there is a bit set
+     * in the incompatible feature set that the kernel doesn't
+     * know about, it should refuse to mount the filesystem.
+     * 
+     * e2fsck's requirements are more strict; if it doesn't know
+     * about a feature in either the compatible or incompatible
+     * feature set, it must abort and not try to meddle with
+     * things it doesn't understand...
+     */
+    __le32  s_first_ino;            /* First non-reserved inode */
+    __le16  s_inode_size;           /* size of inode structure */
+    __le16  s_block_group_nr;       /* block group # of this superblock */
+    __le32  s_feature_compat;       /* compatible feature set */
+    __le32  s_feature_incompat;     /* incompatible feature set */
+    __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
+    __u8    s_uuid[16];             /* 128-bit uuid for volume */
+    char    s_volume_name[16];      /* volume name */
+    char    s_last_mounted[64];     /* directory where last mounted */
+    __le32  s_algorithm_usage_bitmap; /* For compression */
+    /*
+     * Performance hints.  Directory preallocation should only
+     * happen if the EXT2_COMPAT_PREALLOC flag is on.
+     */
+    __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
+    __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
+    __u16   s_padding1;
+    /*
+     * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
+     */
+    __u8    s_journal_uuid[16];     /* uuid of journal superblock */
+    __u32   s_journal_inum;         /* inode number of journal file */
+    __u32   s_journal_dev;          /* device number of journal file */
+    __u32   s_last_orphan;          /* start of list of inodes to delete */
+    __u32   s_hash_seed[4];         /* HTREE hash seed */
+    __u8    s_def_hash_version;     /* Default hash version to use */
+    __u8    s_reserved_char_pad;
+    __u16   s_reserved_word_pad;
+    __le32  s_default_mount_opts;
+    __le32  s_first_meta_bg;        /* First metablock block group */
+    __u32   s_reserved[190];        /* Padding to the end of the block */
+};
+
+/*
+ * Revision levels
+ */
+#define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
+#define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
+
+#define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
+#define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
+
+#define EXT2_GOOD_OLD_INODE_SIZE 128
+
+/*
+ * Feature set definitions
+ */
+
+#define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
+        ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
+#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
+        ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
+#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
+        ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
+#define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
+        EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
+#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
+        EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
+#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
+        EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
+#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
+        EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
+#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
+        EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
+#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
+        EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
+
+#define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
+#define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
+#define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
+#define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
+#define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
+#define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
+
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
+#define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
+
+#define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
+#define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
+#define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
+
+/*
+ * Structure of a directory entry
+ */
+#define EXT2_NAME_LEN 255
+
+struct ext2_dir_entry {
+    __le32  inode;                  /* Inode number */
+    __le16  rec_len;                /* Directory entry length */
+    __u8    name_len;               /* Name length */
+    __u8    file_type;
+    char    name[EXT2_NAME_LEN];    /* File name */
+};
+// NOTE: The original Linux kernel header defines ext2_dir_entry with the original
+//  layout and ext2_dir_entry_2 with the revised layout. We simply use the revised one.
+
+/*
+ * Ext2 directory file types.  Only the low 3 bits are used.  The
+ * other bits are reserved for now.
+ */
+enum {
+    EXT2_FT_UNKNOWN,
+    EXT2_FT_REG_FILE,
+    EXT2_FT_DIR,
+    EXT2_FT_CHRDEV,
+    EXT2_FT_BLKDEV,
+    EXT2_FT_FIFO,
+    EXT2_FT_SOCK,
+    EXT2_FT_SYMLINK,
+    EXT2_FT_MAX
+};
+
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_ext4.c b/ExtPkg/ExtPkgDxe/fsw_ext4.c
new file mode 100644
index 0000000..879cd57
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_ext4.c
@@ -0,0 +1,731 @@ 
+/**
+ * \file fsw_ext4.c
+ * ext4 file system driver code.
+ */
+
+/*-
+ * Copyright (c) 2012 Stefan Agner
+ * Portions Copyright (c) 2006 Christoph Pfisterer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include "fsw_ext4.h"
+
+
+// functions
+
+static fsw_status_t fsw_ext4_volume_mount(struct fsw_ext4_volume *vol);
+static void         fsw_ext4_volume_free(struct fsw_ext4_volume *vol);
+static fsw_status_t fsw_ext4_volume_stat(struct fsw_ext4_volume *vol, struct fsw_volume_stat *sb);
+
+static fsw_status_t fsw_ext4_dnode_fill(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno);
+static void         fsw_ext4_dnode_free(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno);
+static fsw_status_t fsw_ext4_dnode_stat(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_dnode_stat *sb);
+static fsw_status_t fsw_ext4_get_extent(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_extent *extent);
+static fsw_status_t fsw_ext4_get_by_blkaddr(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_extent *extent);
+static fsw_status_t fsw_ext4_get_by_extent(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_extent *extent);
+
+static fsw_status_t fsw_ext4_dir_lookup(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_string *lookup_name, struct fsw_ext4_dnode **child_dno);
+static fsw_status_t fsw_ext4_dir_read(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                      struct fsw_shandle *shand, struct fsw_ext4_dnode **child_dno);
+static fsw_status_t fsw_ext4_read_dentry(struct fsw_shandle *shand, struct ext4_dir_entry *entry);
+
+static fsw_status_t fsw_ext4_readlink(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                      struct fsw_string *link);
+
+//
+// Dispatch Table
+//
+
+struct fsw_fstype_table   FSW_FSTYPE_TABLE_NAME(ext4) = {
+    { FSW_STRING_TYPE_ISO88591, 4, 4, "ext4" },
+    sizeof(struct fsw_ext4_volume),
+    sizeof(struct fsw_ext4_dnode),
+
+    fsw_ext4_volume_mount,
+    fsw_ext4_volume_free,
+    fsw_ext4_volume_stat,
+    fsw_ext4_dnode_fill,
+    fsw_ext4_dnode_free,
+    fsw_ext4_dnode_stat,
+    fsw_ext4_get_extent,
+    fsw_ext4_dir_lookup,
+    fsw_ext4_dir_read,
+    fsw_ext4_readlink,
+};
+
+
+static inline int test_root(fsw_u32 a, int b)
+{
+        int num = b;
+
+        while (a > num)
+                num *= b;
+        return num == a;
+}
+
+static int fsw_ext4_group_sparse(fsw_u32 group)
+{
+        if (group <= 1)
+                return 1;
+        if (!(group & 1))
+                return 0;
+        return (test_root(group, 7) || test_root(group, 5) ||
+                test_root(group, 3));
+}
+
+/* calculate the first block number of the group */
+static inline fsw_u32
+fsw_ext4_group_first_block_no(struct ext4_super_block *sb, fsw_u32 group_no)
+{
+        return group_no * (fsw_u32)EXT4_BLOCKS_PER_GROUP(sb) +
+                sb->s_first_data_block;
+}
+
+/**
+ * Mount an ext4 volume. Reads the superblock and constructs the
+ * root directory dnode.
+ */
+
+static fsw_status_t fsw_ext4_volume_mount(struct fsw_ext4_volume *vol)
+{
+    fsw_status_t    status;
+    void            *buffer;
+    fsw_u32         blocksize;
+    fsw_u32         groupcnt, groupno, gdesc_per_block, gdesc_bno, gdesc_index, metabg_of_gdesc;
+    struct ext4_group_desc *gdesc;
+    int             i;
+    struct fsw_string s;
+
+    // allocate memory to keep the superblock around
+    status = fsw_alloc(sizeof(struct ext4_super_block), &vol->sb);
+    if (status)
+        return status;
+
+    // read the superblock into its buffer
+    fsw_set_blocksize(vol, EXT4_SUPERBLOCK_BLOCKSIZE, EXT4_SUPERBLOCK_BLOCKSIZE);
+    status = fsw_block_get(vol, EXT4_SUPERBLOCK_BLOCKNO, 0, &buffer);
+    if (status)
+        return status;
+    fsw_memcpy(vol->sb, buffer, sizeof(struct ext4_super_block));
+    fsw_block_release(vol, EXT4_SUPERBLOCK_BLOCKNO, buffer);
+
+    // check the superblock
+    if (vol->sb->s_magic != EXT4_SUPER_MAGIC)
+        return FSW_UNSUPPORTED;
+    if (vol->sb->s_rev_level != EXT4_GOOD_OLD_REV &&
+        vol->sb->s_rev_level != EXT4_DYNAMIC_REV)
+        return FSW_UNSUPPORTED;
+
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_volume_mount: Incompat flag %x\n"), vol->sb->s_feature_incompat));
+
+    if (vol->sb->s_rev_level == EXT4_DYNAMIC_REV &&
+        (vol->sb->s_feature_incompat & ~(EXT4_FEATURE_INCOMPAT_FILETYPE | EXT4_FEATURE_INCOMPAT_RECOVER |
+                                         EXT4_FEATURE_INCOMPAT_EXTENTS | EXT4_FEATURE_INCOMPAT_FLEX_BG |
+                                         EXT4_FEATURE_INCOMPAT_META_BG)))
+        return FSW_UNSUPPORTED;
+
+
+    if (vol->sb->s_rev_level == EXT4_DYNAMIC_REV &&
+        (vol->sb->s_feature_incompat & EXT4_FEATURE_INCOMPAT_RECOVER))
+    {
+        FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_volume_mount: This ext3 file system needs recovery\n")));
+        // Print(L"Ext4 WARNING: This file system needs recovery, trying to use it anyway.\n");
+    }
+
+    blocksize = EXT4_BLOCK_SIZE(vol->sb);
+    if (blocksize < EXT4_MIN_BLOCK_SIZE || blocksize > EXT4_MAX_BLOCK_SIZE)
+        return FSW_UNSUPPORTED;
+
+    // set real blocksize
+    fsw_set_blocksize(vol, blocksize, blocksize);
+
+    // get other info from superblock
+    vol->ind_bcnt = EXT4_ADDR_PER_BLOCK(vol->sb);
+    vol->dind_bcnt = vol->ind_bcnt * vol->ind_bcnt;
+    vol->inode_size = vol->sb->s_inode_size;//EXT4_INODE_SIZE(vol->sb);
+
+    for (i = 0; i < 16; i++)
+        if (vol->sb->s_volume_name[i] == 0)
+            break;
+    s.type = FSW_STRING_TYPE_ISO88591;
+    s.size = s.len = i;
+    s.data = vol->sb->s_volume_name;
+    status = fsw_strdup_coerce(&vol->g.label, vol->g.host_string_type, &s);
+    if (status)
+        return status;
+
+    // size of group descriptor depends on feature....
+    if (!(vol->sb->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)) {
+        // Default minimal group descriptor size... (this might not be set in old ext2 filesystems, therefor set it!)
+        vol->sb->s_desc_size = EXT4_MIN_DESC_SIZE;
+    }
+
+    // Calculate group descriptor count the way the kernel does it...
+    groupcnt = (vol->sb->s_blocks_count_lo - vol->sb->s_first_data_block + 
+                vol->sb->s_blocks_per_group - 1) / vol->sb->s_blocks_per_group;
+
+    // Descriptors in one block... s_desc_size needs to be set! (Usually 128 since normal block 
+    // descriptors are 32 byte and block size is 4096)
+    gdesc_per_block = EXT4_DESC_PER_BLOCK(vol->sb);
+    
+    // Read the group descriptors to get inode table offsets
+    status = fsw_alloc(sizeof(fsw_u32) * groupcnt, &vol->inotab_bno);
+    if (status)
+        return status;
+
+    // Loop through all block group descriptors in order to get inode table locations
+    for (groupno = 0; groupno < groupcnt; groupno++) {
+
+        // Calculate the block number which contains the block group descriptor we look for
+        if(vol->sb->s_feature_incompat & EXT4_FEATURE_INCOMPAT_META_BG && groupno >= vol->sb->s_first_meta_bg)
+        {
+            // If option meta_bg is set, the block group descriptor is in meta block group...
+            metabg_of_gdesc = (fsw_u32)(groupno / gdesc_per_block) * gdesc_per_block;
+            gdesc_bno = fsw_ext4_group_first_block_no(vol->sb, metabg_of_gdesc);
+            // We need to know if the block group in questition has a super block, if yes, the 
+            // block group descriptors are in the next block number
+            if(!(vol->sb->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) || fsw_ext4_group_sparse(metabg_of_gdesc))
+                gdesc_bno += 1;
+        }
+        else
+        {
+            // All group descriptors follow the super block (+1)
+            gdesc_bno = (vol->sb->s_first_data_block + 1) + groupno / gdesc_per_block;
+        }
+        gdesc_index = groupno % gdesc_per_block;
+
+        // Get block if necessary...
+        status = fsw_block_get(vol, gdesc_bno, 1, (void **)&buffer);
+        if (status)
+            return status;
+
+        // Get group descriptor table and block number of inode table...
+        gdesc = (struct ext4_group_desc *)(buffer + gdesc_index * vol->sb->s_desc_size);
+        vol->inotab_bno[groupno] = gdesc->bg_inode_table_lo;
+
+        fsw_block_release(vol, gdesc_bno, buffer);
+    }
+
+    // setup the root dnode
+    status = fsw_dnode_create_root(vol, EXT4_ROOT_INO, &vol->g.root);
+    if (status)
+        return status;
+
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_volume_mount: success, blocksize %d\n"), blocksize));
+    AsciiPrint("fsw_ext4_volume_mount: success, blocksize %d\n", blocksize);
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Free the volume data structure. Called by the core after an unmount or after
+ * an unsuccessful mount to release the memory used by the file system type specific
+ * part of the volume structure.
+ */
+
+static void fsw_ext4_volume_free(struct fsw_ext4_volume *vol)
+{
+    if (vol->sb)
+        fsw_free(vol->sb);
+    if (vol->inotab_bno)
+        fsw_free(vol->inotab_bno);
+}
+
+/**
+ * Get in-depth information on a volume.
+ */
+
+static fsw_status_t fsw_ext4_volume_stat(struct fsw_ext4_volume *vol, struct fsw_volume_stat *sb)
+{
+    sb->total_bytes = (fsw_u64)vol->sb->s_blocks_count_lo * vol->g.log_blocksize;
+    sb->free_bytes  = (fsw_u64)vol->sb->s_free_blocks_count_lo * vol->g.log_blocksize;
+    return FSW_SUCCESS;
+}
+
+/**
+ * Get full information on a dnode from disk. This function is called by the core
+ * whenever it needs to access fields in the dnode structure that may not
+ * be filled immediately upon creation of the dnode. In the case of ext4, we
+ * delay fetching of the inode structure until dnode_fill is called. The size and
+ * type fields are invalid until this function has been called.
+ */
+
+static fsw_status_t fsw_ext4_dnode_fill(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno)
+{
+    fsw_status_t    status;
+    fsw_u32         groupno, ino_in_group, ino_bno, ino_index;
+    fsw_u8          *buffer;
+
+    if (dno->raw)
+        return FSW_SUCCESS;
+
+
+    // read the inode block
+    groupno = (dno->g.dnode_id - 1) / vol->sb->s_inodes_per_group;
+    ino_in_group = (dno->g.dnode_id - 1) % vol->sb->s_inodes_per_group;
+    ino_bno = vol->inotab_bno[groupno] +
+        ino_in_group / (vol->g.phys_blocksize / vol->inode_size);
+    ino_index = ino_in_group % (vol->g.phys_blocksize / vol->inode_size);
+    status = fsw_block_get(vol, ino_bno, 2, (void **)&buffer);
+
+    if (status)
+        return status;
+
+    // keep our inode around
+    status = fsw_memdup((void **)&dno->raw, buffer + ino_index * vol->inode_size, vol->inode_size);
+    fsw_block_release(vol, ino_bno, buffer);
+    if (status)
+        return status;
+
+    // get info from the inode
+    dno->g.size = dno->raw->i_size_lo; // TODO: check docs for 64-bit sized files
+
+    if (S_ISREG(dno->raw->i_mode))
+        dno->g.type = FSW_DNODE_TYPE_FILE;
+    else if (S_ISDIR(dno->raw->i_mode))
+        dno->g.type = FSW_DNODE_TYPE_DIR;
+    else if (S_ISLNK(dno->raw->i_mode))
+        dno->g.type = FSW_DNODE_TYPE_SYMLINK;
+    else
+        dno->g.type = FSW_DNODE_TYPE_SPECIAL;
+
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_dnode_fill: inode flags %x\n"), dno->raw->i_flags));
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_dnode_fill: i_mode %x\n"), dno->raw->i_mode));
+    return FSW_SUCCESS;
+}
+
+/**
+ * Free the dnode data structure. Called by the core when deallocating a dnode
+ * structure to release the memory used by the file system type specific part
+ * of the dnode structure.
+ */
+
+static void fsw_ext4_dnode_free(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno)
+{
+    if (dno->raw)
+        fsw_free(dno->raw);
+}
+
+/**
+ * Get in-depth information on a dnode. The core makes sure that fsw_ext4_dnode_fill
+ * has been called on the dnode before this function is called. Note that some
+ * data is not directly stored into the structure, but passed to a host-specific
+ * callback that converts it to the host-specific format.
+ */
+
+static fsw_status_t fsw_ext4_dnode_stat(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_dnode_stat *sb)
+{
+    sb->used_bytes = dno->raw->i_blocks_lo * EXT4_BLOCK_SIZE(vol->sb);   // very, very strange...
+    sb->store_time_posix(sb, FSW_DNODE_STAT_CTIME, dno->raw->i_ctime);
+    sb->store_time_posix(sb, FSW_DNODE_STAT_ATIME, dno->raw->i_atime);
+    sb->store_time_posix(sb, FSW_DNODE_STAT_MTIME, dno->raw->i_mtime);
+    sb->store_attr_posix(sb, dno->raw->i_mode);
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Retrieve file data mapping information. This function is called by the core when
+ * fsw_shandle_read needs to know where on the disk the required piece of the file's
+ * data can be found. The core makes sure that fsw_ext4_dnode_fill has been called
+ * on the dnode before. Our task here is to get the physical disk block number for
+ * the requested logical block number.
+ *
+ * The ext4 file system usually uses extents do to store those disk block numbers.
+ * However, since ext4 is backward compatible, depending on inode flags the old direct
+ * and indirect addressing scheme can still be in place...
+ */
+
+static fsw_status_t fsw_ext4_get_extent(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_extent *extent)
+{
+    // Preconditions: The caller has checked that the requested logical block
+    //  is within the file's size. The dnode has complete information, i.e.
+    //  fsw_ext4_dnode_read_info was called successfully on it.
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_extent: inode %d, block %d\n"), dno->g.dnode_id, extent->log_start));
+    extent->type = FSW_EXTENT_TYPE_PHYSBLOCK;
+    extent->log_count = 1;
+
+    if(dno->raw->i_flags & 1 << EXT4_INODE_EXTENTS)
+    {
+       FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_extent: inode %d uses extents\n"), dno->g.dnode_id));
+       return fsw_ext4_get_by_extent(vol, dno, extent);
+    }
+    else
+    {
+       FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_extent: inode %d uses direct/indirect block addressing\n"),
+           dno->g.dnode_id));
+       return fsw_ext4_get_by_blkaddr(vol, dno, extent);
+    }
+}
+
+/**
+ * New ext4 extents...
+ */
+static fsw_status_t fsw_ext4_get_by_extent(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_extent *extent)
+{
+    fsw_status_t  status;
+    fsw_u32       bno, buf_offset;
+    int           ext_cnt;
+    void          *buffer;
+
+    struct ext4_extent_header  *ext4_extent_header;
+    struct ext4_extent_idx     *ext4_extent_idx;
+    struct ext4_extent         *ext4_extent;
+
+    // Logical block requested by core...
+    bno = extent->log_start;
+
+    // First buffer is the i_block field from inode...
+    buffer = (void *)dno->raw->i_block;
+    buf_offset = 0;
+    while(1) {
+        ext4_extent_header = (struct ext4_extent_header *)buffer + buf_offset;
+        buf_offset += sizeof(struct ext4_extent_header);
+        FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_by_extent: extent header with %d entries\n"), 
+                      ext4_extent_header->eh_entries));
+        if(ext4_extent_header->eh_magic != EXT4_EXT_MAGIC)
+            return FSW_VOLUME_CORRUPTED;
+
+        for(ext_cnt = 0;ext_cnt < ext4_extent_header->eh_entries;ext_cnt++)
+        {
+            if(ext4_extent_header->eh_depth == 0)
+            {
+                // Leaf node, the header follows actual extents
+                ext4_extent = (struct ext4_extent *)(buffer + buf_offset);
+                buf_offset += sizeof(struct ext4_extent);
+                FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_by_extent: extent node cover %d...\n"), ext4_extent->ee_block));
+
+                // Is the requested block in this extent?
+                if(bno >= ext4_extent->ee_block && bno < ext4_extent->ee_block + ext4_extent->ee_len)
+                {
+                    extent->phys_start = ext4_extent->ee_start_lo + (bno - ext4_extent->ee_block);
+                    extent->log_count = ext4_extent->ee_len - (bno - ext4_extent->ee_block);
+                    return FSW_SUCCESS;
+                }
+            }
+            else
+            {
+                FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_by_extent: index extents, depth %d\n"), 
+                          ext4_extent_header->eh_depth));
+                ext4_extent_idx = (struct ext4_extent_idx *)(buffer + buf_offset);
+                buf_offset += sizeof(struct ext4_extent_idx);
+
+                FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_get_by_extent: index node covers block %d...\n"),
+                          ext4_extent_idx->ei_block));
+                if(bno >= ext4_extent_idx->ei_block)
+                {
+                    // Follow extent tree...
+                    status = fsw_block_get(vol, ext4_extent_idx->ei_leaf_lo, 1, (void **)&buffer);
+                    if (status)
+                        return status;
+                    buf_offset = 0;
+                    break;
+                }
+            }
+        }
+    }
+
+    return FSW_NOT_FOUND;
+}
+
+/**
+ * The ext2/ext3 file system does not use extents, but stores a list of block numbers
+ * using the usual direct, indirect, double-indirect, triple-indirect scheme. To
+ * optimize access, this function checks if the following file blocks are mapped
+ * to consecutive disk blocks and returns a combined extent if possible.
+ */
+static fsw_status_t fsw_ext4_get_by_blkaddr(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_extent *extent)
+{
+    fsw_status_t    status;
+    fsw_u32         bno, release_bno, buf_bcnt, file_bcnt;
+    int             path[5], i;
+    fsw_u32         *buffer;
+    bno = extent->log_start;
+
+    // try direct block pointers in the inode
+    if (bno < EXT4_NDIR_BLOCKS) {
+        path[0] = bno;
+        path[1] = -1;
+    } else {
+        bno -= EXT4_NDIR_BLOCKS;
+
+        // try indirect block
+        if (bno < vol->ind_bcnt) {
+            path[0] = EXT4_IND_BLOCK;
+            path[1] = bno;
+            path[2] = -1;
+        } else {
+            bno -= vol->ind_bcnt;
+
+            // try double-indirect block
+            if (bno < vol->dind_bcnt) {
+                path[0] = EXT4_DIND_BLOCK;
+                path[1] = bno / vol->ind_bcnt;
+                path[2] = bno % vol->ind_bcnt;
+                path[3] = -1;
+            } else {
+                bno -= vol->dind_bcnt;
+
+                // use the triple-indirect block
+                path[0] = EXT4_TIND_BLOCK;
+                path[1] = bno / vol->dind_bcnt;
+                path[2] = (bno / vol->ind_bcnt) % vol->ind_bcnt;
+                path[3] = bno % vol->ind_bcnt;
+                path[4] = -1;
+            }
+        }
+    }
+    
+    // follow the indirection path
+    buffer = dno->raw->i_block;
+    buf_bcnt = EXT4_NDIR_BLOCKS;
+    release_bno = 0;
+    for (i = 0; ; i++) {
+        bno = buffer[path[i]];
+        if (bno == 0) {
+            extent->type = FSW_EXTENT_TYPE_SPARSE;
+            if (release_bno)
+                fsw_block_release(vol, release_bno, buffer);
+            return FSW_SUCCESS;
+        }
+        if (path[i+1] < 0)
+            break;
+
+        if (release_bno)
+            fsw_block_release(vol, release_bno, buffer);
+        status = fsw_block_get(vol, bno, 1, (void **)&buffer);
+        if (status)
+            return status;
+        release_bno = bno;
+        buf_bcnt = vol->ind_bcnt;
+    }
+    extent->phys_start = bno;
+
+    // check if the following blocks can be aggregated into one extent
+    file_bcnt = (fsw_u32)((dno->g.size + vol->g.log_blocksize - 1) & (vol->g.log_blocksize - 1));
+    while (path[i]           + extent->log_count < buf_bcnt &&    // indirect block has more block pointers
+           extent->log_start + extent->log_count < file_bcnt) {   // file has more blocks
+        if (buffer[path[i] + extent->log_count] == buffer[path[i] + extent->log_count - 1] + 1)
+            extent->log_count++;
+        else
+            break;
+    }
+
+    if (release_bno)
+        fsw_block_release(vol, release_bno, buffer);
+    return FSW_SUCCESS;
+}
+
+/**
+ * Lookup a directory's child dnode by name. This function is called on a directory
+ * to retrieve the directory entry with the given name. A dnode is constructed for
+ * this entry and returned. The core makes sure that fsw_ext4_dnode_fill has been called
+ * and the dnode is actually a directory.
+ */
+
+static fsw_status_t fsw_ext4_dir_lookup(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                        struct fsw_string *lookup_name, struct fsw_ext4_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+    struct fsw_shandle shand;
+    fsw_u32         child_ino;
+    struct ext4_dir_entry entry;
+    struct fsw_string entry_name;
+
+    // Preconditions: The caller has checked that dno is a directory node.
+
+    entry_name.type = FSW_STRING_TYPE_ISO88591;
+
+    // setup handle to read the directory
+    status = fsw_shandle_open(dno, &shand);
+    if (status)
+        return status;
+
+    // scan the directory for the file
+    child_ino = 0;
+    while (child_ino == 0) {
+        // read next entry
+        status = fsw_ext4_read_dentry(&shand, &entry);
+        if (status)
+            goto errorexit;
+        if (entry.inode == 0) {
+            // end of directory reached
+            status = FSW_NOT_FOUND;
+            goto errorexit;
+        }
+
+        // compare name
+        entry_name.len = entry_name.size = entry.name_len;
+        entry_name.data = entry.name;
+        if (fsw_streq(lookup_name, &entry_name)) {
+            child_ino = entry.inode;
+            break;
+        }
+    }
+
+    // setup a dnode for the child item
+    status = fsw_dnode_create(dno, child_ino, FSW_DNODE_TYPE_UNKNOWN, &entry_name, child_dno_out);
+
+errorexit:
+    fsw_shandle_close(&shand);
+    return status;
+}
+
+/**
+ * Get the next directory entry when reading a directory. This function is called during
+ * directory iteration to retrieve the next directory entry. A dnode is constructed for
+ * the entry and returned. The core makes sure that fsw_ext4_dnode_fill has been called
+ * and the dnode is actually a directory. The shandle provided by the caller is used to
+ * record the position in the directory between calls.
+ */
+
+static fsw_status_t fsw_ext4_dir_read(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                      struct fsw_shandle *shand, struct fsw_ext4_dnode **child_dno_out)
+{
+    fsw_status_t    status;
+    struct ext4_dir_entry entry;
+    struct fsw_string entry_name;
+
+    // Preconditions: The caller has checked that dno is a directory node. The caller
+    //  has opened a storage handle to the directory's storage and keeps it around between
+    //  calls.
+    FSW_MSG_DEBUG((FSW_MSGSTR("fsw_ext4_dir_read: started reading dir\n")));
+
+    while (1) {
+        // read next entry
+        status = fsw_ext4_read_dentry(shand, &entry);
+        if (status)
+            return status;
+        if (entry.inode == 0)   // end of directory
+            return FSW_NOT_FOUND;
+
+        // skip . and ..
+        if ((entry.name_len == 1 && entry.name[0] == '.') ||
+            (entry.name_len == 2 && entry.name[0] == '.' && entry.name[1] == '.'))
+            continue;
+        break;
+    }
+
+    // setup name
+    entry_name.type = FSW_STRING_TYPE_ISO88591;
+    entry_name.len = entry_name.size = entry.name_len;
+    entry_name.data = entry.name;
+
+    // setup a dnode for the child item
+    status = fsw_dnode_create(dno, entry.inode, FSW_DNODE_TYPE_UNKNOWN, &entry_name, child_dno_out);
+
+    return status;
+}
+
+/**
+ * Read a directory entry from the directory's raw data. This internal function is used
+ * to read a raw ext2 directory entry into memory. The shandle's position pointer is adjusted
+ * to point to the next entry.
+ */
+
+static fsw_status_t fsw_ext4_read_dentry(struct fsw_shandle *shand, struct ext4_dir_entry *entry)
+{
+    fsw_status_t    status;
+    fsw_u32         buffer_size;
+
+    while (1) {
+        // read dir_entry header (fixed length)
+        buffer_size = 8;
+        status = fsw_shandle_read(shand, &buffer_size, entry);
+        if (status)
+            return status;
+
+        if (buffer_size < 8 || entry->rec_len == 0) {
+            // end of directory reached
+            entry->inode = 0;
+            return FSW_SUCCESS;
+        }
+        if (entry->rec_len < 8)
+            return FSW_VOLUME_CORRUPTED;
+        if (entry->inode != 0) {
+            // this entry is used
+            if (entry->rec_len < 8 + entry->name_len)
+                return FSW_VOLUME_CORRUPTED;
+            break;
+        }
+
+        // valid, but unused entry, skip it
+        shand->pos += entry->rec_len - 8;
+    }
+
+    // read file name (variable length)
+    buffer_size = entry->name_len;
+    status = fsw_shandle_read(shand, &buffer_size, entry->name);
+    if (status)
+        return status;
+    if (buffer_size < entry->name_len)
+        return FSW_VOLUME_CORRUPTED;
+
+    // skip any remaining padding
+    shand->pos += entry->rec_len - (8 + entry->name_len);
+
+    return FSW_SUCCESS;
+}
+
+/**
+ * Get the target path of a symbolic link. This function is called when a symbolic
+ * link needs to be resolved. The core makes sure that the fsw_ext4_dnode_fill has been
+ * called on the dnode and that it really is a symlink.
+ *
+ * For ext4, the target path can be stored inline in the inode structure (in the space
+ * otherwise occupied by the block pointers) or in the inode's data. There is no flag
+ * indicating this, only the number of blocks entry (i_blocks) can be used as an
+ * indication. The check used here comes from the Linux kernel.
+ */
+
+static fsw_status_t fsw_ext4_readlink(struct fsw_ext4_volume *vol, struct fsw_ext4_dnode *dno,
+                                      struct fsw_string *link_target)
+{
+    fsw_status_t    status;
+    int             ea_blocks;
+    struct fsw_string s;
+
+    if (dno->g.size > FSW_PATH_MAX)
+        return FSW_VOLUME_CORRUPTED;
+
+    /* Linux kernels ext4_inode_is_fast_symlink... */
+    ea_blocks = dno->raw->i_file_acl_lo ? (vol->g.log_blocksize >> 9) : 0;
+
+    if (dno->raw->i_blocks_lo - ea_blocks == 0) {
+        // "fast" symlink, path is stored inside the inode
+        s.type = FSW_STRING_TYPE_ISO88591;
+        s.size = s.len = (int)dno->g.size;
+        s.data = dno->raw->i_block;
+        status = fsw_strdup_coerce(link_target, vol->g.host_string_type, &s);
+    } else {
+        // "slow" symlink, path is stored in normal inode data
+        status = fsw_dnode_readlink_data(dno, link_target);
+    }
+
+    return status;
+}
+
+// EOF
diff --git a/ExtPkg/ExtPkgDxe/fsw_ext4.h b/ExtPkg/ExtPkgDxe/fsw_ext4.h
new file mode 100644
index 0000000..df7ad35
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_ext4.h
@@ -0,0 +1,66 @@ 
+/**
+ * \file fsw_ext4.h
+ * ext4 file system driver header.
+ */
+
+/*-
+ * Copyright (c) 2012 Stefan Agner
+ * Portions Copyright (c) 2006 Christoph Pfisterer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef _FSW_EXT4_H_
+#define _FSW_EXT4_H_
+
+#define VOLSTRUCTNAME fsw_ext4_volume
+#define DNODESTRUCTNAME fsw_ext4_dnode
+#include "fsw_core.h"
+
+#include "fsw_ext4_disk.h"
+
+
+//! Block size to be used when reading the ext4 superblock.
+#define EXT4_SUPERBLOCK_BLOCKSIZE  1024
+//! Block number where the (master copy of the) ext4 superblock resides.
+#define EXT4_SUPERBLOCK_BLOCKNO       1
+
+
+/**
+ * ext4: Volume structure with ext2-specific data.
+ */
+
+struct fsw_ext4_volume {
+    struct fsw_volume g;            //!< Generic volume structure
+    
+    struct ext4_super_block *sb;    //!< Full raw ext2 superblock structure
+    fsw_u32     *inotab_bno;        //!< Block numbers of the inode tables
+    fsw_u32     ind_bcnt;           //!< Number of blocks addressable through an indirect block
+    fsw_u32     dind_bcnt;          //!< Number of blocks addressable through a double-indirect block
+    fsw_u32     inode_size;         //!< Size of inode structure in bytes
+};
+
+/**
+ * ext2: Dnode structure with ext2-specific data.
+ */
+
+struct fsw_ext4_dnode {
+    struct fsw_dnode g;             //!< Generic dnode structure
+    
+    struct ext4_inode *raw;         //!< Full raw inode structure
+};
+
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_ext4_disk.h b/ExtPkg/ExtPkgDxe/fsw_ext4_disk.h
new file mode 100644
index 0000000..2bf3a4e
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_ext4_disk.h
@@ -0,0 +1,500 @@ 
+/**
+ * \file fsw_ext4_disk.h
+ * ext4 file system on-disk structures.
+ */
+
+/*-
+ * Copyright (c) 2012 Stefan Agner
+ * Portions Copyright (c) 2006 Christoph Pfisterer
+ * Portions Copyright (c) 1991-2012 by various Linux kernel contributors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef _FSW_EXT4_DISK_H_
+#define _FSW_EXT4_DISK_H_
+
+// types
+
+typedef fsw_s8  __s8;
+typedef fsw_u8  __u8;
+typedef fsw_s16 __s16;
+typedef fsw_u16 __u16;
+typedef fsw_s32 __s32;
+typedef fsw_u32 __u32;
+typedef fsw_s64 __s64;
+typedef fsw_u64 __u64;
+
+typedef __u16   __le16;
+typedef __u32   __le32;
+typedef __u64   __le64;
+
+//
+// from Linux kernel, fs/ext4/ext4.h
+//
+
+/*
+ * Special inode numbers
+ */
+#define	EXT4_BAD_INO		 1	/* Bad blocks inode */
+#define EXT4_ROOT_INO		 2	/* Root inode */
+#define EXT4_USR_QUOTA_INO	 3	/* User quota inode */
+#define EXT4_GRP_QUOTA_INO	 4	/* Group quota inode */
+#define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
+#define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
+#define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
+#define EXT4_JOURNAL_INO	 8	/* Journal inode */
+
+/*
+ * The second extended file system magic number
+ */
+#define EXT4_SUPER_MAGIC        0xEF53
+
+/*
+ * Macro-instructions used to manage several block sizes
+ */
+#define EXT4_MIN_BLOCK_SIZE             1024
+#define EXT4_MAX_BLOCK_SIZE             4096
+#define EXT4_MIN_BLOCK_LOG_SIZE           10
+#define EXT4_BLOCK_SIZE(s)              (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
+#define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof (__u32))
+#define EXT4_BLOCK_SIZE_BITS(s)         ((s)->s_log_block_size + 10)
+#define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
+                                 EXT4_GOOD_OLD_INODE_SIZE : \
+                                 (s)->s_inode_size)
+
+/*
+ * Structure of a blocks group descriptor
+ */
+struct ext4_group_desc
+{
+	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
+	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
+	__le32	bg_inode_table_lo;	/* Inodes table block */
+	__le16	bg_free_blocks_count_lo;/* Free blocks count */
+	__le16	bg_free_inodes_count_lo;/* Free inodes count */
+	__le16	bg_used_dirs_count_lo;	/* Directories count */
+	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
+	__le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
+	__le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
+	__le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
+	__le16  bg_itable_unused_lo;	/* Unused inodes count */
+	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
+	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
+	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
+	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
+	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
+	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
+	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
+	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
+	__le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
+	__le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
+	__le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
+	__u32   bg_reserved;
+};
+
+
+/*
+ * Macro-instructions used to manage group descriptors
+ */
+#define EXT4_MIN_DESC_SIZE              32
+#define EXT4_MIN_DESC_SIZE_64BIT        64
+#define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
+#define EXT4_DESC_SIZE(s)              ((s)->s_desc_size)
+#define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
+#define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
+#define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
+
+/*
+ * Constants relative to the data blocks
+ */
+#define EXT4_NDIR_BLOCKS                12
+#define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
+#define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
+#define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
+#define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
+
+/*
+ * Inode flags
+ */
+#define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
+#define EXT4_UNRM_FL                    0x00000002 /* Undelete */
+#define EXT4_COMPR_FL                   0x00000004 /* Compress file */
+#define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
+#define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
+#define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
+#define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
+#define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
+/* Reserved for compression usage... */
+#define EXT4_DIRTY_FL                   0x00000100
+#define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
+#define EXT4_NOCOMP_FL                  0x00000400 /* Don't compress */
+#define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
+/* End compression flags --- maybe not all used */      
+#define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
+#define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
+#define EXT4_JOURNAL_DATA_FL            0x00004000 /* Reserved for ext3 */
+#define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
+#define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
+#define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
+#define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
+#define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
+#define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
+#define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
+#define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
+
+#define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
+#define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
+
+
+/*
+ * Structure of an inode on the disk
+ */
+struct ext4_inode {
+	__le16	i_mode;		/* File mode */
+	__le16	i_uid;		/* Low 16 bits of Owner Uid */
+	__le32	i_size_lo;	/* Size in bytes */
+	__le32	i_atime;	/* Access time */
+	__le32	i_ctime;	/* Inode Change time */
+	__le32	i_mtime;	/* Modification time */
+	__le32	i_dtime;	/* Deletion Time */
+	__le16	i_gid;		/* Low 16 bits of Group Id */
+	__le16	i_links_count;	/* Links count */
+	__le32	i_blocks_lo;	/* Blocks count */
+	__le32	i_flags;	/* File flags */
+	union {
+		struct {
+			__le32  l_i_version;
+		} linux1;
+		struct {
+			__u32  h_i_translator;
+		} hurd1;
+		struct {
+			__u32  m_i_reserved1;
+		} masix1;
+	} osd1;				/* OS dependent 1 */
+	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
+	__le32	i_generation;	/* File version (for NFS) */
+	__le32	i_file_acl_lo;	/* File ACL */
+	__le32	i_size_high;
+	__le32	i_obso_faddr;	/* Obsoleted fragment address */
+	union {
+		struct {
+			__le16	l_i_blocks_high; /* were l_i_reserved1 */
+			__le16	l_i_file_acl_high;
+			__le16	l_i_uid_high;	/* these 2 fields */
+			__le16	l_i_gid_high;	/* were reserved2[0] */
+			__le16	l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
+			__le16	l_i_reserved;
+		} linux2;
+		struct {
+			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
+			__u16	h_i_mode_high;
+			__u16	h_i_uid_high;
+			__u16	h_i_gid_high;
+			__u32	h_i_author;
+		} hurd2;
+		struct {
+			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
+			__le16	m_i_file_acl_high;
+			__u32	m_i_reserved2[2];
+		} masix2;
+	} osd2;				/* OS dependent 2 */
+	__le16	i_extra_isize;
+	__le16	i_checksum_hi;	/* crc32c(uuid+inum+inode) BE */
+	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
+	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
+	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
+	__le32  i_crtime;       /* File Creation time */
+	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
+	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
+};
+
+
+/*
+ * Inode flags used for atomic set/get
+ */
+enum {
+	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
+	EXT4_INODE_UNRM		= 1,	/* Undelete */
+	EXT4_INODE_COMPR	= 2,	/* Compress file */
+	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
+	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
+	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
+	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
+	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
+/* Reserved for compression usage... */
+	EXT4_INODE_DIRTY	= 8,
+	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
+	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
+	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
+/* End compression flags --- maybe not all used */
+	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
+	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
+	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
+	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
+	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
+	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
+	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
+	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
+	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
+	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
+	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
+};
+
+/*
+ * Structure of the super block
+ */
+struct ext4_super_block {
+/*00*/	__le32	s_inodes_count;		/* Inodes count */
+	__le32	s_blocks_count_lo;	/* Blocks count */
+	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
+	__le32	s_free_blocks_count_lo;	/* Free blocks count */
+/*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
+	__le32	s_first_data_block;	/* First Data Block */
+	__le32	s_log_block_size;	/* Block size */
+	__le32	s_log_cluster_size;	/* Allocation cluster size */
+/*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
+	__le32	s_clusters_per_group;	/* # Clusters per group */
+	__le32	s_inodes_per_group;	/* # Inodes per group */
+	__le32	s_mtime;		/* Mount time */
+/*30*/	__le32	s_wtime;		/* Write time */
+	__le16	s_mnt_count;		/* Mount count */
+	__le16	s_max_mnt_count;	/* Maximal mount count */
+	__le16	s_magic;		/* Magic signature */
+	__le16	s_state;		/* File system state */
+	__le16	s_errors;		/* Behaviour when detecting errors */
+	__le16	s_minor_rev_level;	/* minor revision level */
+/*40*/	__le32	s_lastcheck;		/* time of last check */
+	__le32	s_checkinterval;	/* max. time between checks */
+	__le32	s_creator_os;		/* OS */
+	__le32	s_rev_level;		/* Revision level */
+/*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
+	__le16	s_def_resgid;		/* Default gid for reserved blocks */
+	/*
+	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
+	 *
+	 * Note: the difference between the compatible feature set and
+	 * the incompatible feature set is that if there is a bit set
+	 * in the incompatible feature set that the kernel doesn't
+	 * know about, it should refuse to mount the filesystem.
+	 *
+	 * e2fsck's requirements are more strict; if it doesn't know
+	 * about a feature in either the compatible or incompatible
+	 * feature set, it must abort and not try to meddle with
+	 * things it doesn't understand...
+	 */
+	__le32	s_first_ino;		/* First non-reserved inode */
+	__le16  s_inode_size;		/* size of inode structure */
+	__le16	s_block_group_nr;	/* block group # of this superblock */
+	__le32	s_feature_compat;	/* compatible feature set */
+/*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
+	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
+/*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
+/*78*/	char	s_volume_name[16];	/* volume name */
+/*88*/	char	s_last_mounted[64];	/* directory where last mounted */
+/*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
+	/*
+	 * Performance hints.  Directory preallocation should only
+	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
+	 */
+	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
+	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
+	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
+	/*
+	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
+	 */
+/*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
+/*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
+	__le32	s_journal_dev;		/* device number of journal file */
+	__le32	s_last_orphan;		/* start of list of inodes to delete */
+	__le32	s_hash_seed[4];		/* HTREE hash seed */
+	__u8	s_def_hash_version;	/* Default hash version to use */
+	__u8	s_jnl_backup_type;
+	__le16  s_desc_size;		/* size of group descriptor */
+/*100*/	__le32	s_default_mount_opts;
+	__le32	s_first_meta_bg;	/* First metablock block group */
+	__le32	s_mkfs_time;		/* When the filesystem was created */
+	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
+	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
+/*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
+	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
+	__le32	s_free_blocks_count_hi;	/* Free blocks count */
+	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
+	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
+	__le32	s_flags;		/* Miscellaneous flags */
+	__le16  s_raid_stride;		/* RAID stride */
+	__le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
+	__le64  s_mmp_block;            /* Block for multi-mount protection */
+	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
+	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
+	__u8	s_checksum_type;	/* metadata checksum algorithm used */
+	__le16  s_reserved_pad;
+	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
+	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
+	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
+	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
+					      snapshot's future use */
+	__le32	s_snapshot_list;	/* inode number of the head of the
+					   on-disk snapshot list */
+#define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
+	__le32	s_error_count;		/* number of fs errors */
+	__le32	s_first_error_time;	/* first time an error happened */
+	__le32	s_first_error_ino;	/* inode involved in first error */
+	__le64	s_first_error_block;	/* block involved of first error */
+	__u8	s_first_error_func[32];	/* function where the error happened */
+	__le32	s_first_error_line;	/* line number where error happened */
+	__le32	s_last_error_time;	/* most recent time of an error */
+	__le32	s_last_error_ino;	/* inode involved in last error */
+	__le32	s_last_error_line;	/* line number where error happened */
+	__le64	s_last_error_block;	/* block involved of last error */
+	__u8	s_last_error_func[32];	/* function where the error happened */
+#define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
+	__u8	s_mount_opts[64];
+	__le32	s_usr_quota_inum;	/* inode for tracking user quota */
+	__le32	s_grp_quota_inum;	/* inode for tracking group quota */
+	__le32	s_overhead_clusters;	/* overhead blocks/clusters in fs */
+	__le32	s_reserved[108];	/* Padding to the end of the block */
+	__le32	s_checksum;		/* crc32c(superblock) */
+};
+
+/*
+ * Revision levels
+ */
+#define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
+#define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
+
+#define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
+#define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
+
+#define EXT4_GOOD_OLD_INODE_SIZE 128
+
+/*
+ * Feature set definitions (only the once we need for read support)
+ */
+#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
+
+#define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
+#define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
+#define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
+#define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
+#define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
+#define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
+#define EXT4_FEATURE_INCOMPAT_MMP               0x0100
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
+#define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
+#define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
+#define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM	0x2000 /* use crc32c for bg */
+#define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
+#define EXT4_FEATURE_INCOMPAT_INLINEDATA	0x8000 /* data in inode */
+
+#define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
+					 EXT4_FEATURE_INCOMPAT_RECOVER| \
+					 EXT4_FEATURE_INCOMPAT_META_BG| \
+					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
+					 EXT4_FEATURE_INCOMPAT_64BIT| \
+					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
+					 EXT4_FEATURE_INCOMPAT_MMP)
+
+/*
+ * Structure of a directory entry
+ */
+#define EXT4_NAME_LEN 255
+
+struct ext4_dir_entry {
+    __le32  inode;                  /* Inode number */
+    __le16  rec_len;                /* Directory entry length */
+    __u8    name_len;               /* Name length */
+    __u8    file_type;
+    char    name[EXT4_NAME_LEN];    /* File name */
+};
+// NOTE: The original Linux kernel header defines ext4_dir_entry with the original
+//  layout and ext4_dir_entry_2 with the revised layout. We simply use the revised one.
+
+/*
+ * Ext2 directory file types.  Only the low 3 bits are used.  The
+ * other bits are reserved for now.
+ */
+enum {
+    EXT4_FT_UNKNOWN,
+    EXT4_FT_REG_FILE,
+    EXT4_FT_DIR,
+    EXT4_FT_CHRDEV,
+    EXT4_FT_BLKDEV,
+    EXT4_FT_FIFO,
+    EXT4_FT_SOCK,
+    EXT4_FT_SYMLINK,
+    EXT4_FT_MAX
+};
+
+/*
+ * ext4_inode has i_block array (60 bytes total).
+ * The first 12 bytes store ext4_extent_header;
+ * the remainder stores an array of ext4_extent.
+ * For non-inode extent blocks, ext4_extent_tail
+ * follows the array.
+ */
+
+/*
+ * This is the extent tail on-disk structure.
+ * All other extent structures are 12 bytes long.  It turns out that
+ * block_size % 12 >= 4 for at least all powers of 2 greater than 512, which
+ * covers all valid ext4 block sizes.  Therefore, this tail structure can be
+ * crammed into the end of the block without having to rebalance the tree.
+ */
+struct ext4_extent_tail {
+	__le32	et_checksum;	/* crc32c(uuid+inum+extent_block) */
+};
+
+/*
+ * This is the extent on-disk structure.
+ * It's used at the bottom of the tree.
+ */
+struct ext4_extent {
+	__le32	ee_block;	/* first logical block extent covers */
+	__le16	ee_len;		/* number of blocks covered by extent */
+	__le16	ee_start_hi;	/* high 16 bits of physical block */
+	__le32	ee_start_lo;	/* low 32 bits of physical block */
+};
+
+/*
+ * This is index on-disk structure.
+ * It's used at all the levels except the bottom.
+ */
+struct ext4_extent_idx {
+	__le32	ei_block;	/* index covers logical blocks from 'block' */
+	__le32	ei_leaf_lo;	/* pointer to the physical block of the next *
+				 * level. leaf or next index could be there */
+	__le16	ei_leaf_hi;	/* high 16 bits of physical block */
+	__u16	ei_unused;
+};
+
+
+/*
+ * Each block (leaves and indexes), even inode-stored has header.
+ */
+struct ext4_extent_header {
+	__le16	eh_magic;	/* probably will support different formats */
+	__le16	eh_entries;	/* number of valid entries */
+	__le16	eh_max;		/* capacity of store in entries */
+	__le16	eh_depth;	/* has tree real underlying blocks? */
+	__le32	eh_generation;	/* generation of the tree */
+};
+
+#define EXT4_EXT_MAGIC		(0xf30a)
+
+
+#endif
diff --git a/ExtPkg/ExtPkgDxe/fsw_lib.c b/ExtPkg/ExtPkgDxe/fsw_lib.c
new file mode 100644
index 0000000..e0af0d3
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_lib.c
@@ -0,0 +1,336 @@ 
+/* $Id: fsw_lib.c 33540 2010-10-28 09:27:05Z vboxsync $ */
+/** @file
+ * fsw_lib.c - Core file system wrapper library functions.
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/*-
+ * This code is based on:
+ *
+ * Copyright (c) 2006 Christoph Pfisterer
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the
+ *    distribution.
+ *
+ *  * Neither the name of Christoph Pfisterer nor the names of the
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fsw_core.h"
+
+/* Include generated string encoding specific functions */
+#include "fsw_strfunc.h"
+
+
+/**
+ * Allocate memory and clear it.
+ */
+
+fsw_status_t fsw_alloc_zero(int len, void **ptr_out)
+{
+    fsw_status_t status;
+
+    status = fsw_alloc(len, ptr_out);
+    if (status)
+        return status;
+    fsw_memzero(*ptr_out, len);
+    return FSW_SUCCESS;
+}
+
+/**
+ * Duplicate a piece of data.
+ */
+
+fsw_status_t fsw_memdup(void **dest_out, void *src, int len)
+{
+    fsw_status_t status;
+
+    status = fsw_alloc(len, dest_out);
+    if (status)
+        return status;
+    fsw_memcpy(*dest_out, src, len);
+    return FSW_SUCCESS;
+}
+
+/**
+ * Get the length of a string. Returns the number of characters in the string.
+ */
+
+int fsw_strlen(struct fsw_string *s)
+{
+    if (s->type == FSW_STRING_TYPE_EMPTY)
+        return 0;
+    return s->len;
+}
+
+static const fsw_u16 fsw_latin_case_fold[] =
+{
+    /* 0 */ 0xFFFF, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000A, 0x000B, 0x000C, 0x000D, 0x000E, 0x000F,
+    /* 1 */ 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001A, 0x001B, 0x001C, 0x001D, 0x001E, 0x001F,
+    /* 2 */ 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002A, 0x002B, 0x002C, 0x002D, 0x002E, 0x002F,
+    /* 3 */ 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003A, 0x003B, 0x003C, 0x003D, 0x003E, 0x003F,
+    /* 4 */ 0x0040, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006A, 0x006B, 0x006C, 0x006D, 0x006E, 0x006F,
+    /* 5 */ 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007A, 0x005B, 0x005C, 0x005D, 0x005E, 0x005F,
+    /* 6 */ 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006A, 0x006B, 0x006C, 0x006D, 0x006E, 0x006F,
+    /* 7 */ 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007A, 0x007B, 0x007C, 0x007D, 0x007E, 0x007F,
+    /* 8 */ 0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087, 0x0088, 0x0089, 0x008A, 0x008B, 0x008C, 0x008D, 0x008E, 0x008F,
+    /* 9 */ 0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097, 0x0098, 0x0099, 0x009A, 0x009B, 0x009C, 0x009D, 0x009E, 0x009F,
+    /* A */ 0x00A0, 0x00A1, 0x00A2, 0x00A3, 0x00A4, 0x00A5, 0x00A6, 0x00A7, 0x00A8, 0x00A9, 0x00AA, 0x00AB, 0x00AC, 0x00AD, 0x00AE, 0x00AF,
+    /* B */ 0x00B0, 0x00B1, 0x00B2, 0x00B3, 0x00B4, 0x00B5, 0x00B6, 0x00B7, 0x00B8, 0x00B9, 0x00BA, 0x00BB, 0x00BC, 0x00BD, 0x00BE, 0x00BF,
+    /* C */ 0x00C0, 0x00C1, 0x00C2, 0x00C3, 0x00C4, 0x00C5, 0x00E6, 0x00C7, 0x00C8, 0x00C9, 0x00CA, 0x00CB, 0x00CC, 0x00CD, 0x00CE, 0x00CF,
+    /* D */ 0x00F0, 0x00D1, 0x00D2, 0x00D3, 0x00D4, 0x00D5, 0x00D6, 0x00D7, 0x00F8, 0x00D9, 0x00DA, 0x00DB, 0x00DC, 0x00DD, 0x00FE, 0x00DF,
+    /* E */ 0x00E0, 0x00E1, 0x00E2, 0x00E3, 0x00E4, 0x00E5, 0x00E6, 0x00E7, 0x00E8, 0x00E9, 0x00EA, 0x00EB, 0x00EC, 0x00ED, 0x00EE, 0x00EF,
+    /* F */ 0x00F0, 0x00F1, 0x00F2, 0x00F3, 0x00F4, 0x00F5, 0x00F6, 0x00F7, 0x00F8, 0x00F9, 0x00FA, 0x00FB, 0x00FC, 0x00FD, 0x00FE, 0x00FF,
+};
+
+
+fsw_u16 fsw_to_lower(fsw_u16 ch)
+{
+    if (ch < 0x0100)
+        return fsw_latin_case_fold[ch];
+    return ch;
+}
+
+/**
+ * Compare two strings for equality. The two strings are compared, taking their
+ * encoding into account. If they are considered equal, boolean true is returned.
+ * Otherwise, boolean false is returned.
+ */
+
+int fsw_streq(struct fsw_string *s1, struct fsw_string *s2)
+{
+    struct fsw_string temp_s;
+
+    // handle empty strings
+    if (s1->type == FSW_STRING_TYPE_EMPTY) {
+        temp_s.type = FSW_STRING_TYPE_ISO88591;
+        temp_s.size = temp_s.len = 0;
+        temp_s.data = NULL;
+        return fsw_streq(&temp_s, s2);
+    }
+    if (s2->type == FSW_STRING_TYPE_EMPTY) {
+        temp_s.type = FSW_STRING_TYPE_ISO88591;
+        temp_s.size = temp_s.len = 0;
+        temp_s.data = NULL;
+        return fsw_streq(s1, &temp_s);
+    }
+
+    // check length (count of chars)
+    if (s1->len != s2->len)
+        return 0;
+    if (s1->len == 0)   // both strings are empty
+        return 1;
+
+    if (s1->type == s2->type) {
+        // same type, do a dumb memory compare
+        if (s1->size != s2->size)
+            return 0;
+        return fsw_memeq(s1->data, s2->data, s1->size);
+    }
+
+    // dispatch to type-specific functions
+    #define STREQ_DISPATCH(type1, type2) \
+      if (s1->type == FSW_STRING_TYPE_##type1 && s2->type == FSW_STRING_TYPE_##type2) \
+        return fsw_streq_##type1##_##type2(s1->data, s2->data, s1->len); \
+      if (s2->type == FSW_STRING_TYPE_##type1 && s1->type == FSW_STRING_TYPE_##type2) \
+        return fsw_streq_##type1##_##type2(s2->data, s1->data, s1->len);
+    STREQ_DISPATCH(ISO88591, UTF8);
+    STREQ_DISPATCH(ISO88591, UTF16);
+    STREQ_DISPATCH(ISO88591, UTF16_SWAPPED);
+    STREQ_DISPATCH(UTF8, UTF16);
+    STREQ_DISPATCH(UTF8, UTF16_SWAPPED);
+    STREQ_DISPATCH(UTF16, UTF16_SWAPPED);
+
+    // final fallback
+    return 0;
+}
+
+/**
+ * Compare a string with a C string constant. This sets up a string descriptor
+ * for the string constant (second argument) and runs fsw_streq on the two
+ * strings. Currently the C string is interpreted as ISO 8859-1.
+ * Returns boolean true if the strings are considered equal, boolean false otherwise.
+ */
+
+int fsw_streq_cstr(struct fsw_string *s1, const char *s2)
+{
+    struct fsw_string temp_s;
+    int i;
+
+    for (i = 0; s2[i]; i++)
+        ;
+
+    temp_s.type = FSW_STRING_TYPE_ISO88591;
+    temp_s.size = temp_s.len = i;
+    temp_s.data = (char *)s2;
+
+    return fsw_streq(s1, &temp_s);
+}
+
+/**
+ * Creates a duplicate of a string, converting it to the given encoding during the copy.
+ * If the function returns FSW_SUCCESS, the caller must free the string later with
+ * fsw_strfree.
+ */
+
+fsw_status_t fsw_strdup_coerce(struct fsw_string *dest, int type, struct fsw_string *src)
+{
+    fsw_status_t    status;
+
+    if (src->type == FSW_STRING_TYPE_EMPTY || src->len == 0) {
+        dest->type = type;
+        dest->size = dest->len = 0;
+        dest->data = NULL;
+        return FSW_SUCCESS;
+    }
+
+    if (src->type == type) {
+        dest->type = type;
+        dest->len  = src->len;
+        dest->size = src->size;
+        status = fsw_alloc(dest->size, &dest->data);
+        if (status)
+            return status;
+
+        fsw_memcpy(dest->data, src->data, dest->size);
+        return FSW_SUCCESS;
+    }
+
+    // dispatch to type-specific functions
+    #define STRCOERCE_DISPATCH(type1, type2) \
+      if (src->type == FSW_STRING_TYPE_##type1 && type == FSW_STRING_TYPE_##type2) \
+        return fsw_strcoerce_##type1##_##type2(src->data, src->len, dest);
+    STRCOERCE_DISPATCH(UTF8, ISO88591);
+    STRCOERCE_DISPATCH(UTF16, ISO88591);
+    STRCOERCE_DISPATCH(UTF16_SWAPPED, ISO88591);
+    STRCOERCE_DISPATCH(ISO88591, UTF8);
+    STRCOERCE_DISPATCH(UTF16, UTF8);
+    STRCOERCE_DISPATCH(UTF16_SWAPPED, UTF8);
+    STRCOERCE_DISPATCH(ISO88591, UTF16);
+    STRCOERCE_DISPATCH(UTF8, UTF16);
+    STRCOERCE_DISPATCH(UTF16_SWAPPED, UTF16);
+
+    return FSW_UNSUPPORTED;
+}
+
+/**
+ * Splits a string at the first occurrence of the separator character.
+ * The buffer string is searched for the separator character. If it is found, the
+ * element string descriptor is filled to point at the part of the buffer string
+ * before the separator. The buffer string itself is adjusted to point at the
+ * remaining part of the string (without the separator).
+ *
+ * If the separator is not found in the buffer string, then element is changed to
+ * point at the whole buffer string, and the buffer string itself is changed into
+ * an empty string.
+ *
+ * This function only manipulates the pointers and lengths in the two string descriptors,
+ * it does not change the actual string. If the buffer string is dynamically allocated,
+ * you must make a copy of it so that you can release it later.
+ */
+
+void fsw_strsplit(struct fsw_string *element, struct fsw_string *buffer, char separator)
+{
+    int i, maxlen;
+
+    if (buffer->type == FSW_STRING_TYPE_EMPTY || buffer->len == 0) {
+        element->type = FSW_STRING_TYPE_EMPTY;
+        return;
+    }
+
+    maxlen = buffer->len;
+    *element = *buffer;
+
+    if (buffer->type == FSW_STRING_TYPE_ISO88591) {
+        fsw_u8 *p;
+
+        p = (fsw_u8 *)element->data;
+        for (i = 0; i < maxlen; i++, p++) {
+            if (*p == separator) {
+                buffer->data = p + 1;
+                buffer->len -= i + 1;
+                break;
+            }
+        }
+        element->len = i;
+        if (i == maxlen) {
+            buffer->data = p;
+            buffer->len -= i;
+        }
+
+        element->size = element->len;
+        buffer->size  = buffer->len;
+
+    } else if (buffer->type == FSW_STRING_TYPE_UTF16) {
+        fsw_u16 *p;
+
+        p = (fsw_u16 *)element->data;
+        for (i = 0; i < maxlen; i++, p++) {
+            if (*p == separator) {
+                buffer->data = p + 1;
+                buffer->len -= i + 1;
+                break;
+            }
+        }
+        element->len = i;
+        if (i == maxlen) {
+            buffer->data = p;
+            buffer->len -= i;
+        }
+
+        element->size = element->len * sizeof(fsw_u16);
+        buffer->size  = buffer->len  * sizeof(fsw_u16);
+
+    } else {
+        // fallback
+        buffer->type = FSW_STRING_TYPE_EMPTY;
+    }
+
+    // TODO: support UTF8 and UTF16_SWAPPED
+}
+
+/**
+ * Frees the memory used by a string returned from fsw_strdup_coerce.
+ */
+
+void fsw_strfree(struct fsw_string *s)
+{
+    if (s->type != FSW_STRING_TYPE_EMPTY && s->data)
+        fsw_free(s->data);
+    s->type = FSW_STRING_TYPE_EMPTY;
+}
+
+// EOF
diff --git a/ExtPkg/ExtPkgDxe/fsw_strfunc.h b/ExtPkg/ExtPkgDxe/fsw_strfunc.h
new file mode 100644
index 0000000..61cf25d
--- /dev/null
+++ b/ExtPkg/ExtPkgDxe/fsw_strfunc.h
@@ -0,0 +1,472 @@ 
+/* $Id: fsw_strfunc.h 29125 2010-05-06 09:43:05Z vboxsync $ */
+/** @file
+ * fsw_strfunc.h
+ */
+
+/*
+ * Copyright (C) 2010 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ */
+
+/* fsw_strfunc.h generated by mk_fsw_strfunc.py */
+
+static int fsw_streq_ISO88591_UTF8(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u8 *p1 = (fsw_u8 *)s1data;
+    fsw_u8 *p2 = (fsw_u8 *)s2data;
+    fsw_u32 c1, c2;
+    
+    for (i = 0; i < len; i++) {
+        c1 = *p1++;
+        c2 = *p2++;
+        if ((c2 & 0xe0) == 0xc0) {
+            c2 = ((c2 & 0x1f) << 6) | (*p2++ & 0x3f);
+        } else if ((c2 & 0xf0) == 0xe0) {
+            c2 = ((c2 & 0x0f) << 12) | ((*p2++ & 0x3f) << 6);
+            c2 |= (*p2++ & 0x3f);
+        } else if ((c2 & 0xf8) == 0xf0) {
+            c2 = ((c2 & 0x07) << 18) | ((*p2++ & 0x3f) << 12);
+            c2 |= ((*p2++ & 0x3f) << 6);
+            c2 |= (*p2++ & 0x3f);
+        }
+        if (c1 != c2)
+            return 0;
+    }
+    return 1;
+}
+
+#ifndef HOST_EFI
+static int fsw_streq_ISO88591_UTF16(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u8 *p1 = (fsw_u8 *)s1data;
+    fsw_u16 *p2 = (fsw_u16 *)s2data;
+    fsw_u32 c1, c2;
+    
+    for (i = 0; i < len; i++) {
+        c1 = *p1++;
+        c2 = *p2++;
+        if (c1 != c2)
+            return 0;
+    }
+    return 1;
+}
+#endif
+
+static int fsw_streq_ISO88591_UTF16_SWAPPED(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u8 *p1 = (fsw_u8 *)s1data;
+    fsw_u16 *p2 = (fsw_u16 *)s2data;
+    fsw_u32 c1, c2;
+    
+    for (i = 0; i < len; i++) {
+        c1 = *p1++;
+        c2 = *p2++; c2 = FSW_SWAPVALUE_U16(c2);
+        if (c1 != c2)
+            return 0;
+    }
+    return 1;
+}
+
+static int fsw_streq_UTF8_UTF16(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u8 *p1 = (fsw_u8 *)s1data;
+    fsw_u16 *p2 = (fsw_u16 *)s2data;
+    fsw_u32 c1, c2;
+    
+    for (i = 0; i < len; i++) {
+        c1 = *p1++;
+        if ((c1 & 0xe0) == 0xc0) {
+            c1 = ((c1 & 0x1f) << 6) | (*p1++ & 0x3f);
+        } else if ((c1 & 0xf0) == 0xe0) {
+            c1 = ((c1 & 0x0f) << 12) | ((*p1++ & 0x3f) << 6);
+            c1 |= (*p1++ & 0x3f);
+        } else if ((c1 & 0xf8) == 0xf0) {
+            c1 = ((c1 & 0x07) << 18) | ((*p1++ & 0x3f) << 12);
+            c1 |= ((*p1++ & 0x3f) << 6);
+            c1 |= (*p1++ & 0x3f);
+        }
+        c2 = *p2++;
+        if (c1 != c2)
+            return 0;
+    }
+    return 1;
+}
+
+static int fsw_streq_UTF8_UTF16_SWAPPED(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u8 *p1 = (fsw_u8 *)s1data;
+    fsw_u16 *p2 = (fsw_u16 *)s2data;
+    fsw_u32 c1, c2;
+    
+    for (i = 0; i < len; i++) {
+        c1 = *p1++;
+        if ((c1 & 0xe0) == 0xc0) {
+            c1 = ((c1 & 0x1f) << 6) | (*p1++ & 0x3f);
+        } else if ((c1 & 0xf0) == 0xe0) {
+            c1 = ((c1 & 0x0f) << 12) | ((*p1++ & 0x3f) << 6);
+            c1 |= (*p1++ & 0x3f);
+        } else if ((c1 & 0xf8) == 0xf0) {
+            c1 = ((c1 & 0x07) << 18) | ((*p1++ & 0x3f) << 12);
+            c1 |= ((*p1++ & 0x3f) << 6);
+            c1 |= (*p1++ & 0x3f);
+        }
+        c2 = *p2++; c2 = FSW_SWAPVALUE_U16(c2);
+        if (c1 != c2)
+            return 0;
+    }
+    return 1;
+}
+
+static int fsw_streq_UTF16_UTF16_SWAPPED(void *s1data, void *s2data, int len)
+{
+    int i;
+    fsw_u16 *p1 = (fsw_u16 *)s1data;
+    fsw_u16 *p2 = (fsw_u16 *)s2data;
+    fsw_u32 c1, c2;
+    
+    for (i = 0; i < len; i++) {
+        c1 = *p1++;
+        c2 = *p2++; c2 = FSW_SWAPVALUE_U16(c2);
+        if (c1 != c2)
+            return 0;
+    }
+    return 1;
+}
+
+static fsw_status_t fsw_strcoerce_UTF8_ISO88591(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i;
+    fsw_u8       *sp;
+    fsw_u8       *dp;
+    fsw_u32         c;
+    
+    dest->type = FSW_STRING_TYPE_ISO88591;
+    dest->len  = srclen;
+    dest->size = srclen * sizeof(fsw_u8);
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u8 *)srcdata;
+    dp = (fsw_u8 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        if ((c & 0xe0) == 0xc0) {
+            c = ((c & 0x1f) << 6) | (*sp++ & 0x3f);
+        } else if ((c & 0xf0) == 0xe0) {
+            c = ((c & 0x0f) << 12) | ((*sp++ & 0x3f) << 6);
+            c |= (*sp++ & 0x3f);
+        } else if ((c & 0xf8) == 0xf0) {
+            c = ((c & 0x07) << 18) | ((*sp++ & 0x3f) << 12);
+            c |= ((*sp++ & 0x3f) << 6);
+            c |= (*sp++ & 0x3f);
+        }
+        *dp++ = (fsw_u8)c;
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_UTF16_ISO88591(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i;
+    fsw_u16       *sp;
+    fsw_u8       *dp;
+    fsw_u32         c;
+    
+    dest->type = FSW_STRING_TYPE_ISO88591;
+    dest->len  = srclen;
+    dest->size = srclen * sizeof(fsw_u8);
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u16 *)srcdata;
+    dp = (fsw_u8 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        *dp++ = (fsw_u8)c;
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_UTF16_SWAPPED_ISO88591(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i;
+    fsw_u16       *sp;
+    fsw_u8       *dp;
+    fsw_u32         c;
+    
+    dest->type = FSW_STRING_TYPE_ISO88591;
+    dest->len  = srclen;
+    dest->size = srclen * sizeof(fsw_u8);
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u16 *)srcdata;
+    dp = (fsw_u8 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++; c = FSW_SWAPVALUE_U16(c);
+        *dp++ = (fsw_u8)c;
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_ISO88591_UTF16(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i;
+    fsw_u8       *sp;
+    fsw_u16       *dp;
+    fsw_u32         c;
+    
+    dest->type = FSW_STRING_TYPE_UTF16;
+    dest->len  = srclen;
+    dest->size = srclen * sizeof(fsw_u16);
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u8 *)srcdata;
+    dp = (fsw_u16 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        *dp++ = (fsw_u16)c;
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_UTF8_UTF16(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i;
+    fsw_u8       *sp;
+    fsw_u16       *dp;
+    fsw_u32         c;
+    
+    dest->type = FSW_STRING_TYPE_UTF16;
+    dest->len  = srclen;
+    dest->size = srclen * sizeof(fsw_u16);
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u8 *)srcdata;
+    dp = (fsw_u16 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        if ((c & 0xe0) == 0xc0) {
+            c = ((c & 0x1f) << 6) | (*sp++ & 0x3f);
+        } else if ((c & 0xf0) == 0xe0) {
+            c = ((c & 0x0f) << 12) | ((*sp++ & 0x3f) << 6);
+            c |= (*sp++ & 0x3f);
+        } else if ((c & 0xf8) == 0xf0) {
+            c = ((c & 0x07) << 18) | ((*sp++ & 0x3f) << 12);
+            c |= ((*sp++ & 0x3f) << 6);
+            c |= (*sp++ & 0x3f);
+        }
+        *dp++ = (fsw_u16)c;
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_UTF16_SWAPPED_UTF16(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i;
+    fsw_u16       *sp;
+    fsw_u16       *dp;
+    fsw_u32         c;
+    
+    dest->type = FSW_STRING_TYPE_UTF16;
+    dest->len  = srclen;
+    dest->size = srclen * sizeof(fsw_u16);
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u16 *)srcdata;
+    dp = (fsw_u16 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++; c = FSW_SWAPVALUE_U16(c);
+        *dp++ = (fsw_u16)c;
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_ISO88591_UTF8(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i, destsize;
+    fsw_u8       *sp;
+    fsw_u8       *dp;
+    fsw_u32         c;
+    
+    sp = (fsw_u8 *)srcdata;
+    destsize = 0;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        
+        if (c < 0x000080)
+            destsize++;
+        else if (c < 0x000800)
+            destsize += 2;
+        else if (c < 0x010000)
+            destsize += 3;
+        else
+            destsize += 4;
+    }
+    
+    dest->type = FSW_STRING_TYPE_UTF8;
+    dest->len  = srclen;
+    dest->size = destsize;
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u8 *)srcdata;
+    dp = (fsw_u8 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        
+        if (c < 0x000080) {
+            *dp++ = (fsw_u8)c;
+        } else if (c < 0x000800) {
+            *dp++ = (fsw_u8)(0xc0 | ((c >> 6) & 0x1f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        } else if (c < 0x010000) {
+            *dp++ = (fsw_u8)(0xe0 | ((c >> 12) & 0x0f));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 6) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        } else {
+            *dp++ = (fsw_u8)(0xf0 | ((c >> 18) & 0x07));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 12) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 6) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        }
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_UTF16_UTF8(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i, destsize;
+    fsw_u16       *sp;
+    fsw_u8       *dp;
+    fsw_u32         c;
+    
+    sp = (fsw_u16 *)srcdata;
+    destsize = 0;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        
+        if (c < 0x000080)
+            destsize++;
+        else if (c < 0x000800)
+            destsize += 2;
+        else if (c < 0x010000)
+            destsize += 3;
+        else
+            destsize += 4;
+    }
+    
+    dest->type = FSW_STRING_TYPE_UTF8;
+    dest->len  = srclen;
+    dest->size = destsize;
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u16 *)srcdata;
+    dp = (fsw_u8 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++;
+        
+        if (c < 0x000080) {
+            *dp++ = (fsw_u8)c;
+        } else if (c < 0x000800) {
+            *dp++ = (fsw_u8)(0xc0 | ((c >> 6) & 0x1f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        } else if (c < 0x010000) {
+            *dp++ = (fsw_u8)(0xe0 | ((c >> 12) & 0x0f));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 6) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        } else {
+            *dp++ = (fsw_u8)(0xf0 | ((c >> 18) & 0x07));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 12) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 6) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        }
+    }
+    return FSW_SUCCESS;
+}
+
+static fsw_status_t fsw_strcoerce_UTF16_SWAPPED_UTF8(void *srcdata, int srclen, struct fsw_string *dest)
+{
+    fsw_status_t    status;
+    int             i, destsize;
+    fsw_u16       *sp;
+    fsw_u8       *dp;
+    fsw_u32         c;
+    
+    sp = (fsw_u16 *)srcdata;
+    destsize = 0;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++; c = FSW_SWAPVALUE_U16(c);
+        
+        if (c < 0x000080)
+            destsize++;
+        else if (c < 0x000800)
+            destsize += 2;
+        else if (c < 0x010000)
+            destsize += 3;
+        else
+            destsize += 4;
+    }
+    
+    dest->type = FSW_STRING_TYPE_UTF8;
+    dest->len  = srclen;
+    dest->size = destsize;
+    status = fsw_alloc(dest->size, &dest->data);
+    if (status)
+        return status;
+    
+    sp = (fsw_u16 *)srcdata;
+    dp = (fsw_u8 *)dest->data;
+    for (i = 0; i < srclen; i++) {
+        c = *sp++; c = FSW_SWAPVALUE_U16(c);
+        
+        if (c < 0x000080) {
+            *dp++ = (fsw_u8)c;
+        } else if (c < 0x000800) {
+            *dp++ = (fsw_u8)(0xc0 | ((c >> 6) & 0x1f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        } else if (c < 0x010000) {
+            *dp++ = (fsw_u8)(0xe0 | ((c >> 12) & 0x0f));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 6) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        } else {
+            *dp++ = (fsw_u8)(0xf0 | ((c >> 18) & 0x07));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 12) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | ((c >> 6) & 0x3f));
+            *dp++ = (fsw_u8)(0x80 | (c & 0x3f));
+        }
+    }
+    return FSW_SUCCESS;
+}
diff --git a/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.dsc b/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.dsc
index ade2997..dcfb56a 100755
--- a/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.dsc
+++ b/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.dsc
@@ -305,6 +305,7 @@ 
   #
   MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIoDxe.inf
   MdeModulePkg/Universal/Disk/PartitionDxe/PartitionDxe.inf
+  ExtPkg/ExtPkgDxe/Ext.inf
   FatPkg/EnhancedFatDxe/Fat.inf
   MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
 
diff --git a/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.fdf b/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.fdf
index 9bccd79..0748bc0 100755
--- a/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.fdf
+++ b/SamsungPlatformPkg/ArndaleBoardPkg/arndale-Exynos5250.fdf
@@ -193,6 +193,7 @@  READ_LOCK_STATUS   = TRUE
   #
   INF MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIoDxe.inf
   INF MdeModulePkg/Universal/Disk/PartitionDxe/PartitionDxe.inf
+  INF ExtPkg/ExtPkgDxe/Ext.inf
   INF FatPkg/EnhancedFatDxe/Fat.inf
   INF MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf