[v2,1/3] arm64: Add Xen boot support file

From: Fu Wei <fu.wei@linaro.org>

This patch adds Xen boot support file:
grub-core/loader/arm64/xen_boot.c
include/grub/arm64/xen_boot.h

This patch also adds commands register code and hearder file into
grub-core/loader/arm64/linux.c

  - This adds support for the Xen boot on ARM specification for arm64.
  - The implementation for Xen is following  <Multiboot on ARM Specification>:
      http://wiki.xen.org/wiki/Xen_ARM_with_Virtualization_Extensions/Multiboot
    and xen/docs/misc/arm/device-tree/booting.txt in Xen source code.
  - The multiboot/module commands have existed,
    so we use xen_hypervisor/xen_module instead.
  - This Xen boot support is built into linux module for aarch64.
  - Adding this functionality to the existing "linux" module is for
    reusing the existing code of devicetree.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
---
 grub-core/Makefile.core.def       |   1 +
 grub-core/loader/arm64/linux.c    |   6 +
 grub-core/loader/arm64/xen_boot.c | 615 ++++++++++++++++++++++++++++++++++++++
 include/grub/arm64/xen_boot.h     | 115 +++++++
 4 files changed, 737 insertions(+)
 create mode 100644 grub-core/loader/arm64/xen_boot.c
 create mode 100644 include/grub/arm64/xen_boot.h

Hi Vladimir,

I have submitted a new patchset (v3) for xen boot.
this patchset follows all your comment here.

please help me again on this, Great thanks for your help.

On 16 July 2015 at 00:18, Vladimir 'φ-coder/phcoder' Serbinenko
<phcoder@gmail.com> wrote:
> On 13.07.2015 10:53, fu.wei@linaro.org wrote:
>> From: Fu Wei <fu.wei@linaro.org>
>>
>> This patch adds Xen boot support file:
>> grub-core/loader/arm64/xen_boot.c
>> include/grub/arm64/xen_boot.h
>>
>> This patch also adds commands register code and hearder file into
>> grub-core/loader/arm64/linux.c
>>
>>   - This adds support for the Xen boot on ARM specification for arm64.
>>   - The implementation for Xen is following  <Multiboot on ARM Specification>:
>>       http://wiki.xen.org/wiki/Xen_ARM_with_Virtualization_Extensions/Multiboot
> Please don't refer to this protocol as multiboot anywhere in grub or
> around because it's NOT multiboot and we don't want to confuse those 2
> protocols.
>>     and xen/docs/misc/arm/device-tree/booting.txt in Xen source code.
>>   - The multiboot/module commands have existed,
>>     so we use xen_hypervisor/xen_module instead.
>>   - This Xen boot support is built into linux module for aarch64.
>>   - Adding this functionality to the existing "linux" module is for
>>     reusing the existing code of devicetree.
>>
> Please create separate module. Modules are dynamically linked.
>> Signed-off-by: Fu Wei <fu.wei@linaro.org>
>> ---
>>  grub-core/Makefile.core.def       |   1 +
>>  grub-core/loader/arm64/linux.c    |   6 +
>>  grub-core/loader/arm64/xen_boot.c | 615 ++++++++++++++++++++++++++++++++++++++
>>  include/grub/arm64/xen_boot.h     | 115 +++++++
>>  4 files changed, 737 insertions(+)
>>  create mode 100644 grub-core/loader/arm64/xen_boot.c
>>  create mode 100644 include/grub/arm64/xen_boot.h
>>
>> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
>> index a6101de..01f8261 100644
>> --- a/grub-core/Makefile.core.def
>> +++ b/grub-core/Makefile.core.def
>> @@ -1659,6 +1659,7 @@ module = {
>>    ia64_efi = loader/ia64/efi/linux.c;
>>    arm = loader/arm/linux.c;
>>    arm64 = loader/arm64/linux.c;
>> +  arm64 = loader/arm64/xen_boot.c;
>>    fdt = lib/fdt.c;
>>    common = loader/linux.c;
>>    common = lib/cmdline.c;
>> diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c
>> index 987f5b9..7ae9bde 100644
>> --- a/grub-core/loader/arm64/linux.c
>> +++ b/grub-core/loader/arm64/linux.c
>> @@ -26,6 +26,7 @@
>>  #include <grub/mm.h>
>>  #include <grub/types.h>
>>  #include <grub/cpu/linux.h>
>> +#include <grub/cpu/xen_boot.h>
>>  #include <grub/efi/efi.h>
>>  #include <grub/efi/pe32.h>
>>  #include <grub/i18n.h>
>> @@ -477,6 +478,9 @@ GRUB_MOD_INIT (linux)
>>    cmd_devicetree =
>>      grub_register_command ("devicetree", grub_cmd_devicetree, 0,
>>                          N_("Load DTB file."));
>> +
>> +  grub_arm64_linux_register_xen_boot_command (mod, &loaded);
>> +
>>    my_mod = mod;
>>  }
>>
>> @@ -485,4 +489,6 @@ GRUB_MOD_FINI (linux)
>>    grub_unregister_command (cmd_linux);
>>    grub_unregister_command (cmd_initrd);
>>    grub_unregister_command (cmd_devicetree);
>> +
>> +  grub_arm64_linux_unregister_xen_boot_command ();
>>  }
> Not needed with separate module.
>> diff --git a/grub-core/loader/arm64/xen_boot.c b/grub-core/loader/arm64/xen_boot.c
>> new file mode 100644
>> index 0000000..23bd00e
>> --- /dev/null
>> +++ b/grub-core/loader/arm64/xen_boot.c
>> @@ -0,0 +1,615 @@
>> +/*
>> + *  GRUB  --  GRand Unified Bootloader
>> + *  Copyright (C) 2014  Free Software Foundation, Inc.
>> + *
>> + *  GRUB 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 3 of the License, or
>> + *  (at your option) any later version.
>> + *
>> + *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <grub/cache.h>
>> +#include <grub/charset.h>
>> +#include <grub/command.h>
>> +#include <grub/err.h>
>> +#include <grub/file.h>
>> +#include <grub/fdt.h>
>> +#include <grub/linux.h>
>> +#include <grub/list.h>
>> +#include <grub/loader.h>
>> +#include <grub/misc.h>
>> +#include <grub/mm.h>
>> +#include <grub/types.h>
>> +#include <grub/cpu/linux.h>
>> +#include <grub/cpu/xen_boot.h>
>> +#include <grub/efi/efi.h>
>> +#include <grub/efi/pe32.h>
>> +#include <grub/i18n.h>
>> +#include <grub/lib/cmdline.h>
>> +
>> +static grub_dl_t linux_mod;
>> +static int *loaded;
>> +
>> +static struct xen_boot_binary *xen_hypervisor;
>> +static struct xen_boot_binary *module_head;
>> +static const grub_size_t module_default_align[] = {
>> +  MODULE_IMAGE_MIN_ALIGN,
>> +  MODULE_INITRD_MIN_ALIGN,
>> +  MODULE_OTHER_MIN_ALIGN,
>> +  MODULE_CUSTOM_MIN_ALIGN
>> +};
>> +
>> +static void *xen_boot_fdt;
>> +static const compat_string_struct_t default_compat_string[] = {
>> +  FDT_COMPATIBLE (MODULE_IMAGE_COMPATIBLE),
>> +  FDT_COMPATIBLE (MODULE_INITRD_COMPATIBLE),
>> +  FDT_COMPATIBLE (MODULE_OTHER_COMPATIBLE)
>> +};
>> +
>> +
>> +/* Parse all the options of xen_module command. For now, we support
>> +   (1) --type <the compatible stream>
>> +   (2) --nounzip
>> +   We also set up the type of module in this function.
>> +   If there are some "--type" options in the command line,
>> +   we make a custom compatible stream in this function. */
>> +static grub_err_t
>> +set_module_type (struct xen_boot_binary *module, int argc, char *argv[],
>> +              int *file_name_index)
>> +{
>> +  char **compat_string_temp_array =
>> +    (char **) grub_zalloc (sizeof (char *) * argc);
>> +  static module_type_t default_type = MODULE_IMAGE;
>> +  grub_size_t total_size = 0;
>> +  int num_types = 0, i;
>> +  char *temp = NULL;
>> +
>> +  *file_name_index = 0;
>> +
>> +  /* if there are some options we need to process. */
>> +  while (argc > 1 && !grub_strncmp (argv[0], "--", 2))
>> +    {
>> +      if (!grub_strcmp (argv[0], "--type"))
>> +     {
>> +       module->node_info.type = MODULE_CUSTOM;
>> +       ARG_SHIFT (argc, argv);
>> +       total_size += grub_strlen (argv[0]) + 1;
>> +       compat_string_temp_array[num_types++] = argv[0];
>> +       ARG_SHIFT (argc, argv);
>> +       (*file_name_index) += 2;
> This (and subsequent) parsing is unecessarily complicated. Please create
> separate commands for different types
>> +     }
>> +      else if (!grub_strcmp (argv[0], "--nounzip"))
>> +     {
>> +       grub_file_filter_disable_compression ();
>> +       ARG_SHIFT (argc, argv);
>> +       (*file_name_index) += 1;
>> +     }
>> +      else                   /* we can add more options process code here. */
>> +     {
>> +       grub_dprintf ("xen_boot_loader",
>> +                     "Unknown option %s, skip.\n", argv[0]);
>> +       ARG_SHIFT (argc, argv);
>> +       (*file_name_index) += 1;
>> +     }
>> +    }
>> +
>> +  /* To prevent some wrong command lines using "--type" option */
>> +  if (!argc)
>> +    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
>> +
>> +  /* For the default module type :
>> +     The implementation is following <Multiboot on ARM Specification>:
>> +     Each module will be given a default compatibility property
>> +     based on the order in which the modules are added.
>> +     The 1st module: compatible = "multiboot,kernel", "multiboot,module"
>> +     The 2nd module: compatible = "multiboot,ramdisk", "multiboot,module"
>> +     All subsequent modules: compatible = "multiboot,module"
>> +     But this order will NOT be interfered with "--type"(MODULE_CUSTOM)
>> +     For more detail, please refer to:
>> +     http://wiki.xen.org/wiki/Xen_ARM_with_Virtualization_Extensions/Multiboot */
>> +  if (module->node_info.type != MODULE_CUSTOM)
>> +    {
>> +      /* the module type is set by the load order */
>> +      module->node_info.type = default_type;
> Please don't make it order-dependent more than necessarry.
>> +      switch (default_type)
>> +     {
>> +     case MODULE_IMAGE:
>> +       default_type = MODULE_INITRD;
>> +       break;
>> +
>> +     case MODULE_INITRD:
>> +       default_type = MODULE_OTHER;
>> +       break;
>> +
>> +     case MODULE_OTHER:
>> +       break;
>> +
>> +     default:
>> +       default_type = MODULE_IMAGE;  /* error, reset the type */
>> +       return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
>> +     }
>> +    }
>> +  else
>> +    {
>> +      /* the module type is set by "--type"(MODULE_CUSTOM) */
>> +      module->node_info.compat_string = temp =
>> +     (char *) grub_zalloc (total_size);
>> +      module->node_info.compat_string_size = total_size;
>> +      for (i = 0; num_types > 0; num_types--, i++, temp++)
>> +     {
>> +       grub_strcpy (temp, compat_string_temp_array[i]);
>> +       temp += grub_strlen (compat_string_temp_array[i]);
>> +     }
>> +    }
>> +
>> +  grub_free (compat_string_temp_array);
>> +
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +prepare_xen_hypervisor_params (void)
>> +{
>> +  int chosen_node = 0;
>> +  int retval;
>> +
>> +  xen_boot_fdt = grub_linux_get_fdt ();
>> +  if (!xen_boot_fdt)
>> +    return grub_error (GRUB_ERR_BAD_OS, "failed to get FDT");
>> +
>> +  chosen_node = grub_fdt_find_subnode (xen_boot_fdt, 0, "chosen");
>> +  if (chosen_node < 0)
>> +    chosen_node = grub_fdt_add_subnode (xen_boot_fdt, 0, "chosen");
>> +  if (chosen_node < 1)
>> +    return grub_error (GRUB_ERR_BAD_OS, "failed to get chosen node in FDT");
>> +
> BAD_OS means that OS images are invalid. ERR_IO is a generic error for
> such cases.
>> +  grub_dprintf ("xen_boot_loader",
>> +             "Xen Hypervisor cmdline : %s @ %p size:%d\n",
>> +             xen_hypervisor->cmdline, xen_hypervisor->cmdline,
>> +             xen_hypervisor->cmdline_size);
>> +
> No need for "boot_". xen_loader is fine and mre consistent.
>> +  retval = grub_fdt_set_prop (xen_boot_fdt, chosen_node, "bootargs",
>> +                           xen_hypervisor->cmdline,
>> +                           xen_hypervisor->cmdline_size);
>> +  if (retval)
>> +    return grub_error (GRUB_ERR_BAD_OS, "failed to install/update FDT");
>> +
> ditto
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +prepare_xen_module_params (struct xen_boot_binary *module)
>> +{
>> +  int retval, chosen_node = 0, module_node = 0;
>> +  char module_name[FDT_NODE_NAME_MAX_SIZE];
>> +
>> +  retval = grub_snprintf (module_name, FDT_NODE_NAME_MAX_SIZE, "module@%lx",
>> +                       xen_boot_address_align (module->start,
>> +                                               module->align));
>> +  grub_dprintf ("xen_boot_loader", "Module node name %s \n", module_name);
>> +
>> +  if (retval < (int) sizeof ("module@"))
>> +    return grub_error (GRUB_ERR_BAD_OS, N_("failed to get FDT"));
>> +
>> +  chosen_node = grub_fdt_find_subnode (xen_boot_fdt, 0, "chosen");
>> +  if (chosen_node < 0)
>> +    chosen_node = grub_fdt_add_subnode (xen_boot_fdt, 0, "chosen");
>> +  if (chosen_node < 1)
>> +    return grub_error (GRUB_ERR_BAD_OS, "failed to get chosen node in FDT");
>> +
>> +  module_node =
>> +    grub_fdt_find_subnode (xen_boot_fdt, chosen_node, module_name);
>> +  if (module_node < 0)
>> +    module_node =
>> +      grub_fdt_add_subnode (xen_boot_fdt, chosen_node, module_name);
>> +
>> +  retval = grub_fdt_set_prop (xen_boot_fdt, module_node, "compatible",
>> +                           module->node_info.compat_string,
>> +                           (grub_uint32_t) module->node_info.
>> +                           compat_string_size);
>> +  if (retval)
>> +    return grub_error (GRUB_ERR_BAD_OS, N_("failed to update FDT"));
>> +
>> +  grub_dprintf ("xen_boot_loader", "Module %s compatible = %s size = 0x%lx\n",
>> +             module->name, module->node_info.compat_string,
>> +             module->node_info.compat_string_size);
>> +
>> +  retval = grub_fdt_set_reg64 (xen_boot_fdt, module_node,
>> +                            xen_boot_address_align (module->start,
>> +                                                    module->align),
>> +                            module->size);
>> +  if (retval)
>> +    return grub_error (GRUB_ERR_BAD_OS, N_("failed to update FDT"));
>> +
>> +  if (module->cmdline && module->cmdline_size > 0)
>> +    {
>> +      grub_dprintf ("xen_boot_loader",
>> +                 "Module %s cmdline : %s @ %p size:%d\n", module->name,
>> +                 module->cmdline, module->cmdline, module->cmdline_size);
>> +
>> +      retval = grub_fdt_set_prop (xen_boot_fdt, module_node, "bootargs",
>> +                               module->cmdline, module->cmdline_size + 1);
>> +      if (retval)
>> +     return grub_error (GRUB_ERR_BAD_OS, "failed to update FDT");
>> +    }
>> +  else
>> +    {
>> +      grub_dprintf ("xen_boot_loader", "Module %s has not bootargs!\n",
>> +                 module->name);
>> +    }
>> +
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +install_all_params (void)
>> +{
>> +  grub_efi_guid_t fdt_guid = GRUB_EFI_DEVICE_TREE_GUID;
>> +  grub_efi_boot_services_t *b;
>> +  grub_efi_status_t status;
>> +
>> +  b = grub_efi_system_table->boot_services;
>> +  status = b->install_configuration_table (&fdt_guid, xen_boot_fdt);
>> +  if (status != GRUB_EFI_SUCCESS)
>> +    return grub_error (GRUB_ERR_BAD_OS, "failed to install FDT");
>> +
>> +  grub_dprintf ("xen_boot_loader",
>> +             "Installed/updated FDT configuration table @ %p\n",
>> +             xen_boot_fdt);
>> +
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +clean_all_params (void)
>> +{
>> +  if (xen_boot_fdt)
>> +    {
>> +      grub_efi_free_pages ((grub_efi_physical_address_t) xen_boot_fdt,
>> +                        BYTES_TO_PAGES (grub_fdt_get_totalsize
>> +                                        (xen_boot_fdt)));
>> +      xen_boot_fdt = NULL;
>> +    }
>> +
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +finalize_params_xen_boot (void)
>> +{
>> +  struct xen_boot_binary *module;
>> +
>> +  if (xen_hypervisor)
>> +    {
>> +      if (prepare_xen_hypervisor_params () != GRUB_ERR_NONE)
>> +     goto fail;
>> +    }
>> +  else
>> +    {
>> +      grub_dprintf ("xen_boot_loader",
>> +                 "Failed to get Xen Hypervisor info!\n");
>> +      goto fail;
>> +    }
>> +
>> +  /* Set module params info */
>> +  FOR_LIST_ELEMENTS (module, module_head)
>> +  {
>> +    if (module->start && module->size > 0)
>> +      {
>> +     grub_dprintf ("xen_boot_loader", "Module %s @ 0x%lx size:0x%lx\n",
>> +                   module->name,
>> +                   xen_boot_address_align (module->start, module->align),
>> +                   module->size);
>> +     if (prepare_xen_module_params (module) != GRUB_ERR_NONE)
>> +       goto fail;
>> +      }
>> +    else
>> +      {
>> +     grub_dprintf ("xen_boot_loader", "Module info error: %s!\n",
>> +                   module->name);
>> +     goto fail;
>> +      }
>> +  }
>> +
>> +  if (install_all_params () == GRUB_ERR_NONE)
>> +    return GRUB_ERR_NONE;
>> +
>> +fail:
>> +  clean_all_params ();
>> +
>> +  return grub_error (GRUB_ERR_BAD_OS, "failed to install/update FDT");
>> +}
>> +
>> +
>> +static grub_err_t
>> +xen_boot (void)
>> +{
>> +  if (finalize_params_xen_boot () != GRUB_ERR_NONE)
>> +    return grub_errno;
>> +
> Better use err = finalize_params_xen_boot (); if (err) return err;
>> +  return grub_arm64_uefi_boot_image (xen_hypervisor->start,
>> +                                  xen_hypervisor->size,
>> +                                  xen_hypervisor->cmdline);
>> +}
>> +
>> +static void
>> +single_binary_unload (struct xen_boot_binary *binary)
>> +{
> Just put if (!binary) return; It will save a lot of if's.
>> +  if (binary && binary->start && binary->size > 0)
>> +    {
>> +      grub_efi_free_pages ((grub_efi_physical_address_t) binary->start,
>> +                        BYTES_TO_PAGES (binary->size + binary->align));
>> +    }
>> +
>> +  if (binary && binary->cmdline && binary->cmdline_size > 0)
>> +    {
>> +      grub_free (binary->cmdline);
>> +      grub_dprintf ("xen_boot_loader",
>> +                 "Module %s cmdline memory free @ %p size: %d\n",
>> +                 binary->name, binary->cmdline, binary->cmdline_size);
>> +    }
>> +
>> +  if (binary)
>> +    {
>> +      if (binary->node_info.type == MODULE_CUSTOM)
>> +     grub_free ((void *) binary->node_info.compat_string);
>> +      if (grub_strcmp (binary->name, XEN_HYPERVISOR_NAME))
>> +     grub_list_remove (GRUB_AS_LIST (binary));
>> +      grub_dprintf ("xen_boot_loader",
>> +                 "Module %s struct memory free @ %p size: 0x%lx\n",
>> +                 binary->name, binary, sizeof (binary));
>> +      grub_free (binary);
>> +    }
>> +
>> +  return;
>> +}
>> +
>> +static void
>> +all_binaries_unload (void)
>> +{
>> +  struct xen_boot_binary *binary;
>> +
>> +  FOR_LIST_ELEMENTS (binary, module_head)
>> +  {
>> +    single_binary_unload (binary);
>> +  }
>> +
>> +  if (xen_hypervisor)
>> +    single_binary_unload (xen_hypervisor);
>> +
>> +  return;
>> +}
>> +
>> +static grub_err_t
>> +xen_unload (void)
>> +{
>> +  *loaded = 0;
>> +  all_binaries_unload ();
>> +  clean_all_params ();
>> +  grub_dl_unref (linux_mod);
>> +
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +xen_boot_binary_load (struct xen_boot_binary *binary, grub_file_t file,
>> +                   int argc, char *argv[])
>> +{
>> +  binary->size = grub_file_size (file);
>> +  grub_dprintf ("xen_boot_loader", "Xen_boot %s file size: 0x%lx\n",
>> +             binary->name, binary->size);
>> +
>> +  binary->start = (grub_addr_t) grub_efi_allocate_pages (0,
>> +                                                      (BYTES_TO_PAGES
>> +                                                       (binary->size +
>> +                                                        binary->align)));
>> +  if (!binary->start)
>> +    return grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
>> +
>> +  grub_dprintf ("xen_boot_loader", "Xen_boot %s numpages: 0x%lx\n",
>> +             binary->name, BYTES_TO_PAGES (binary->size + binary->align));
>> +
>> +  if (grub_file_read (file, (void *) xen_boot_address_align (binary->start,
>> +                                                          binary->align),
>> +                   binary->size) < (grub_ssize_t) binary->size)
>> +    {
> We use != throughout. It's safer.
>> +      single_binary_unload (binary);
>> +      return grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
>> +                      argv[0]);
>> +    }
>> +
>> +  /* Skip the xen_boot binary file name */
>> +  ARG_SHIFT (argc, argv);
>> +
> There shouldn't be any need for shifting. Just use argc - 1 and argv + 1
>> +  if (argc > 0)
>> +    {
>> +      binary->cmdline_size = grub_loader_cmdline_size (argc, argv);
>> +      binary->cmdline = grub_zalloc (binary->cmdline_size);
>> +      if (!binary->cmdline)
>> +     {
>> +       single_binary_unload (binary);
>> +       return grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
>> +     }
>> +      grub_create_loader_cmdline (argc, argv, binary->cmdline,
>> +                               binary->cmdline_size);
>> +      grub_dprintf ("xen_boot_loader",
>> +                 "Xen_boot %s cmdline @ %p %s, size: %d\n", binary->name,
>> +                 binary->cmdline, binary->cmdline, binary->cmdline_size);
>> +    }
>> +  else
>> +    {
>> +      binary->cmdline_size = 0;
>> +      binary->cmdline = NULL;
>> +    }
>> +
>> +  return GRUB_ERR_NONE;
>> +}
>> +
>> +static grub_err_t
>> +grub_cmd_xen_module (grub_command_t cmd __attribute__ ((unused)),
>> +                  int argc, char *argv[])
>> +{
>> +
>> +  struct xen_boot_binary *module = NULL;
>> +  int file_name_index = 0;
>> +  grub_file_t file = 0;
>> +
>> +  if (!argc)
>> +    {
>> +      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
>> +      goto fail;
>> +    }
>> +
>> +  if (!*loaded)
>> +    {
>> +      grub_error (GRUB_ERR_BAD_ARGUMENT,
>> +               N_("you need to load the Xen Hypervisor first"));
>> +      goto fail;
>> +    }
>> +
>> +  module =
>> +    (struct xen_boot_binary *) grub_zalloc (sizeof (struct xen_boot_binary));
>> +  if (!module)
>> +    return grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
>> +
> Just return grub_errno; zalloc already calls grub_error
>> +  /* process all the options and get module type */
>> +  if (set_module_type (module, argc, argv, &file_name_index) != GRUB_ERR_NONE)
>> +    goto fail;
>> +  switch (module->node_info.type)
>> +    {
>> +    case MODULE_IMAGE:
>> +    case MODULE_INITRD:
>> +    case MODULE_OTHER:
>> +      module->node_info.compat_string =
>> +     default_compat_string[module->node_info.type].compat_string;
>> +      module->node_info.compat_string_size =
>> +     default_compat_string[module->node_info.type].size;
>> +      break;
>> +
>> +    case MODULE_CUSTOM:
>> +      /* we have set the node_info in set_module_type */
>> +      break;
>> +
>> +    default:
>> +      return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
>> +    }
>> +  module->name = module->node_info.compat_string;
>> +  module->align = module_default_align[module->node_info.type];
>> +
>> +  grub_dprintf ("xen_boot_loader", "Init %s module and node info:\n"
>> +             "compatible %s\ncompat_string_size 0x%lx\n",
>> +             module->name, module->node_info.compat_string,
>> +             module->node_info.compat_string_size);
>> +
>> +  file = grub_file_open (argv[file_name_index]);
>> +  if (!file)
>> +    goto fail;
>> +
>> +  grub_errno = xen_boot_binary_load (module, file, argc - file_name_index,
>> +                                  argv + file_name_index);
>> +
> When you call grub_error. grub_errno is already set
>> +  if (grub_errno == GRUB_ERR_NONE)
>> +    grub_list_push (GRUB_AS_LIST_P (&module_head), GRUB_AS_LIST (module));
>> +
>> +fail:
>> +  if (file)
>> +    grub_file_close (file);
>> +  if (grub_errno != GRUB_ERR_NONE)
>> +    single_binary_unload (module);
>> +
>> +  return grub_errno;
>> +}
>> +
>> +static grub_err_t
>> +grub_cmd_xen_hypervisor (grub_command_t cmd __attribute__ ((unused)),
>> +                      int argc, char *argv[])
>> +{
>> +  struct xen_hypervisor_header sh;
>> +  grub_file_t file = NULL;
>> +
>> +  grub_dl_ref (linux_mod);
>> +
>> +  if (!argc)
>> +    {
>> +      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
>> +      goto fail;
>> +    }
>> +
>> +  /* For now, we don't support any option in xen_hypervisor command.
>> +     If there are some options, we skip them. */
>> +  while (argc > 1 && !grub_strncmp (argv[0], "--", 2))
>> +    {
>> +      grub_dprintf ("xen_boot_loader", "Unknown option %s, skip.\n", argv[0]);
>> +      ARG_SHIFT (argc, argv);
>> +    }
>> +
> Why do you need this? Just delete it.
>> +  file = grub_file_open (argv[0]);
>> +  if (!file)
>> +    goto fail;
>> +
>> +  if (grub_file_read (file, &sh, sizeof (sh)) < (long) sizeof (sh))
>> +    goto fail;
>> +  if (grub_arm64_uefi_check_image
>> +      ((struct grub_arm64_linux_kernel_header *) &sh) != GRUB_ERR_NONE)
>> +    goto fail;
>> +  grub_file_seek (file, 0);
>> +
>> +  grub_loader_unset ();
>> +
> This is implicit in loader_set. Please add a comment why it needs to be
> explicit. I suppose it's to avoid unloading oneself.
>> +  xen_hypervisor =
>> +    (struct xen_boot_binary *) grub_zalloc (sizeof (struct xen_boot_binary));
>> +  if (!xen_hypervisor)
>> +    return grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
>> +
> Ditto
>> +  xen_hypervisor->name = XEN_HYPERVISOR_NAME;
>> +  xen_hypervisor->align = (grub_size_t) sh.optional_header.section_alignment;
>> +
>> +  grub_errno = xen_boot_binary_load (xen_hypervisor, file, argc, argv);
>> +  if (grub_errno == GRUB_ERR_NONE)
>> +    {
>> +      grub_loader_set (xen_boot, xen_unload, 0);
>> +      *loaded = 1;
>> +    }
>> +
>> +fail:
>> +  if (file)
>> +    grub_file_close (file);
>> +  if (grub_errno != GRUB_ERR_NONE)
>> +    {
>> +      *loaded = 0;
>> +      all_binaries_unload ();
>> +      grub_dl_unref (linux_mod);
>> +    }
>> +
>> +  return grub_errno;
>> +}
>> +
>> +static grub_command_t cmd_xen_hypervisor, cmd_xen_module;
>> +
>> +void
>> +grub_arm64_linux_register_xen_boot_command (grub_dl_t mod, int *linux_loaded)
>> +{
>> +  cmd_xen_hypervisor =
>> +    grub_register_command ("xen_hypervisor", grub_cmd_xen_hypervisor, 0,
>> +                        N_("Load a xen hypervisor."));
>> +  cmd_xen_module =
>> +    grub_register_command ("xen_module", grub_cmd_xen_module, 0,
>> +                        N_("Load a xen module."));
>> +  linux_mod = mod;
>> +  loaded = linux_loaded;
>> +}
>> +
>> +void
>> +grub_arm64_linux_unregister_xen_boot_command (void)
>> +{
>> +  grub_unregister_command (cmd_xen_hypervisor);
>> +  grub_unregister_command (cmd_xen_module);
>> +}
>> diff --git a/include/grub/arm64/xen_boot.h b/include/grub/arm64/xen_boot.h
>> new file mode 100644
>> index 0000000..8e8f6cb
>> --- /dev/null
>> +++ b/include/grub/arm64/xen_boot.h
>> @@ -0,0 +1,115 @@
>> +/*
>> + *  xen_boot.h - Xen boot header file for Xen boot via FDT
>> + *  on AArch64 architecture.
>> + *  Copyright (C) 2014  Free Software Foundation, Inc.
>> + *
>> + *  GRUB 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 3 of the License, or
>> + *  (at your option) any later version.
>> + *
>> + *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef XEN_BOOT_HEADER
>> +#define XEN_BOOT_HEADER 1
>> +
>> +#include <grub/list.h>
>> +#include <grub/types.h>
>> +#include <grub/efi/pe32.h>   /* required by struct xen_hypervisor_header */
>> +
> This file doesn't really look like having anything reusable. Please put
> it directly into .c
>> +#define XEN_HYPERVISOR_NAME  "xen_hypervisor"
>> +
>> +#define MODULE_DEFAULT_ALIGN  (0x0)
>> +#define MODULE_IMAGE_MIN_ALIGN  MODULE_DEFAULT_ALIGN
>> +#define MODULE_INITRD_MIN_ALIGN  MODULE_DEFAULT_ALIGN
>> +#define MODULE_OTHER_MIN_ALIGN  MODULE_DEFAULT_ALIGN
>> +#define MODULE_CUSTOM_MIN_ALIGN  MODULE_DEFAULT_ALIGN
>> +
>> +#define MODULE_IMAGE_COMPATIBLE  "multiboot,kernel\0multiboot,module"
>> +#define MODULE_INITRD_COMPATIBLE  "multiboot,ramdisk\0multiboot,module"
>> +#define MODULE_OTHER_COMPATIBLE  "multiboot,module"
>> +
>> +/* This maximum size is defined in Power.org ePAPR V1.1
>> + * https://www.power.org/documentation/epapr-version-1-1/
>> + * 2.2.1.1 Node Name Requirements
>> + * node-name@unit-address
>> + * 31 + 1(@) + 16(64bit address in hex format) + 1(\0) = 49
>> + */
>> +#define FDT_NODE_NAME_MAX_SIZE  (49)
>> +
>> +#define ARG_SHIFT(argc, argv) \
>> +  do { \
>> +    (argc)--; \
>> +    (argv)++; \
>> +  } while (0)
>> +
>> +struct compat_string_struct
>> +{
>> +  grub_size_t size;
>> +  const char *compat_string;
>> +};
>> +typedef struct compat_string_struct compat_string_struct_t;
>> +#define FDT_COMPATIBLE(x) {.size = sizeof(x), .compat_string = (x)}
>> +
>> +enum module_type
>> +{
>> +  MODULE_IMAGE,
>> +  MODULE_INITRD,
>> +  MODULE_OTHER,
>> +  MODULE_CUSTOM
>> +};
>> +typedef enum module_type module_type_t;
>> +
>> +struct fdt_node_info
>> +{
>> +  module_type_t type;
>> +
>> +  const char *compat_string;
>> +  grub_size_t compat_string_size;
>> +};
>> +
>> +struct xen_hypervisor_header
>> +{
>> +  struct grub_arm64_linux_kernel_header efi_head;
>> +
>> +  /* This is always PE\0\0.  */
>> +  grub_uint8_t signature[GRUB_PE32_SIGNATURE_SIZE];
>> +  /* The COFF file header.  */
>> +  struct grub_pe32_coff_header coff_header;
>> +  /* The Optional header.  */
>> +  struct grub_pe64_optional_header optional_header;
>> +};
>> +
>> +struct xen_boot_binary
>> +{
>> +  struct xen_boot_binary *next;
>> +  struct xen_boot_binary **prev;
>> +  const char *name;
>> +
>> +  grub_addr_t start;
>> +  grub_size_t size;
>> +  grub_size_t align;
>> +
>> +  char *cmdline;
>> +  int cmdline_size;
>> +
>> +  struct fdt_node_info node_info;
>> +};
>> +
>> +void grub_arm64_linux_register_xen_boot_command (grub_dl_t mod, int *loaded);
>> +void grub_arm64_linux_unregister_xen_boot_command (void);
>> +
>> +static __inline grub_addr_t
>> +xen_boot_address_align (grub_addr_t start, grub_size_t align)
>> +{
>> +  return (align ? (ALIGN_UP (start, align)) : start);
>> +}
>> +
>> +#endif /* ! XEN_BOOT_HEADER */
>>
>
>