@@ -5,6 +5,17 @@
#include "efistub.h"
+static struct screen_info *si;
+
+struct screen_info *alloc_screen_info(void)
+{
+ return si;
+}
+
+void free_screen_info(struct screen_info *si)
+{
+}
+
/*
* EFI entry point for the generic EFI stub used by ARM, arm64, RISC-V and
* LoongArch. This is the entrypoint that is described in the PE/COFF header
@@ -56,6 +67,9 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
return status;
}
+ /* point si to the relocated copy of struct screen_info */
+ si = (void *)&screen_info + image_addr - (unsigned long)image->image_base;
+
status = efi_stub_common(handle, image, image_addr, cmdline_ptr);
efi_free(image_size, image_addr);
@@ -47,15 +47,6 @@
static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0);
-struct screen_info * __weak alloc_screen_info(void)
-{
- return &screen_info;
-}
-
-void __weak free_screen_info(struct screen_info *si)
-{
-}
-
static struct screen_info *setup_graphics(void)
{
efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
@@ -15,14 +15,7 @@
* early, but it only works if the EFI stub is part of the core kernel image
* itself. The zboot decompressor can only use the configuration table
* approach.
- *
- * In order to support both methods from the same build of the EFI stub
- * library, provide this dummy global definition of struct screen_info. If it
- * is required to satisfy a link dependency, it means we need to override the
- * __weak alloc and free methods with the ones below, and those will be pulled
- * in as well.
*/
-struct screen_info screen_info;
static efi_guid_t screen_info_guid = LINUX_EFI_SCREEN_INFO_TABLE_GUID;
In some cases, we expose the kernel's struct screen_info to the EFI stub directly, so it gets populated before even entering the kernel. This means the early console is available as soon as the early param parsing happens, which is nice. It also means we need two different ways to pass this information, as this trick only works if the EFI stub is baked into the core kernel image, which is not always the case. Huacai reports that the preparatory refactoring that was needed to implement this alternative method for zboot resulted in a non-functional efifb earlycon for other cases as well, due to the reordering of the kernel image relocation with the population of the screen_info struct, and the latter now takes place after copying the image to its new location, which means we copy the old, uninitialized state. So let's ensure that alloc_screen_info() produces the correct screen_info pointer, by keeping its relocated address in a global variable. Cc: loongarch@lists.linux.dev Cc: Xuefeng Li <lixuefeng@loongson.cn> Cc: Xuerui Wang <kernel@xen0n.name> Cc: loongson-kernel@lists.loongnix.cn Reported-by: Huacai Chen <chenhuacai@loongson.cn> Link: https://lore.kernel.org/linux-efi/20230310021749.921041-1-chenhuacai@loongson.cn/ Fixes: 42c8ea3dca094ab8 ("efi: libstub: Factor out EFI stub entrypoint into separate file") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/libstub/efi-stub-entry.c | 14 ++++++++++++++ drivers/firmware/efi/libstub/efi-stub.c | 9 --------- drivers/firmware/efi/libstub/screen_info.c | 7 ------- 3 files changed, 14 insertions(+), 16 deletions(-)