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| author | Ard Biesheuvel <ardb@kernel.org> | 2022-11-22 17:10:03 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-11-22 19:21:26 +0100 |
| commit | 5c3a85f35b583259cf5ca0344cd79c8899ba1bb7 (patch) | |
| tree | f5176e3327b833a05d396fe8eabd759fcbbbaa52 /arch/x86/boot/compressed/head_64.S | |
| parent | e2ab9eab324cdf240de89741e4a1aa79919f0196 (diff) | |
| download | lwn-5c3a85f35b583259cf5ca0344cd79c8899ba1bb7.tar.gz lwn-5c3a85f35b583259cf5ca0344cd79c8899ba1bb7.zip | |
x86/boot/compressed: Move bootargs parsing out of 32-bit startup code
Move the logic that chooses between the different EFI entrypoints out of
the 32-bit boot path, and into a 64-bit helper that can perform the same
task much more cleanly. While at it, document the mixed mode boot flow
in a code comment.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221122161017.2426828-4-ardb@kernel.org
Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 24 |
1 files changed, 4 insertions, 20 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 5d07ef750def..f3d7de52e252 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -261,25 +261,9 @@ SYM_FUNC_START(startup_32) */ leal rva(startup_64)(%ebp), %eax #ifdef CONFIG_EFI_MIXED - movl rva(efi32_boot_args)(%ebp), %edi - testl %edi, %edi - jz 1f - leal rva(efi64_stub_entry)(%ebp), %eax - movl rva(efi32_boot_args+4)(%ebp), %esi - movl rva(efi32_boot_args+8)(%ebp), %edx // saved bootparams pointer - testl %edx, %edx - jnz 1f - /* - * efi_pe_entry uses MS calling convention, which requires 32 bytes of - * shadow space on the stack even if all arguments are passed in - * registers. We also need an additional 8 bytes for the space that - * would be occupied by the return address, and this also results in - * the correct stack alignment for entry. - */ - subl $40, %esp - leal rva(efi_pe_entry)(%ebp), %eax - movl %edi, %ecx // MS calling convention - movl %esi, %edx + cmpb $1, rva(efi_is64)(%ebp) + je 1f + leal rva(startup_64_mixed_mode)(%ebp), %eax 1: #endif /* Check if the C-bit position is correct when SEV is active */ @@ -779,7 +763,7 @@ SYM_DATA_END_LABEL(boot32_idt, SYM_L_GLOBAL, boot32_idt_end) SYM_DATA(image_offset, .long 0) #endif #ifdef CONFIG_EFI_MIXED -SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0) +SYM_DATA(efi32_boot_args, .long 0, 0, 0) SYM_DATA(efi_is64, .byte 1) #define ST32_boottime 60 // offsetof(efi_system_table_32_t, boottime) |