The special EFI handover protocol entrypoint offset wrt to the startup_XX address is described in struct boot_params as handover_offset, so that the special Linux/x86 aware EFI loader can find it there. When mixed mode is enabled, this single field has to describe this offset for both the 32-bit and 64-bit entrypoints, so their respective relative offsets have to be identical. Currently, we use hard-coded fixed offsets to ensure this, but the only requirement is that the entrypoints are 0x200 bytes apart, and this only matters when EFI mixed mode is configured to begin with. So just set the required offset directly. This could potentially result in a build error if the 32-bit startup code is much smaller than the 64-bit code but this is currently far from the case, and easily fixed when that situation does arise. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- arch/x86/boot/compressed/head_64.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index b7599cbbd2ea1136..72780644a2272af8 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -282,7 +282,6 @@ SYM_FUNC_START(startup_32) SYM_FUNC_END(startup_32) #if IS_ENABLED(CONFIG_EFI_MIXED) && IS_ENABLED(CONFIG_EFI_HANDOVER_PROTOCOL) - .org 0x190 SYM_FUNC_START(efi32_stub_entry) add $0x4, %esp /* Discard return address */ popl %ecx @@ -455,7 +454,9 @@ SYM_CODE_START(startup_64) SYM_CODE_END(startup_64) #ifdef CONFIG_EFI_HANDOVER_PROTOCOL - .org 0x390 +#ifdef CONFIG_EFI_MIXED + .org efi32_stub_entry + 0x200 +#endif SYM_FUNC_START(efi64_stub_entry) and $~0xf, %rsp /* realign the stack */ call efi_handover_entry -- 2.39.2
