diff options
| author | Ivan Gorinov <ivan.gorinov@intel.com> | 2018-06-13 17:27:39 -0700 |
|---|---|---|
| committer | Bin Meng <bmeng.cn@gmail.com> | 2018-06-17 21:16:04 +0800 |
| commit | 9f0b0113c975d08c7fc5a509d67f128515486c0c (patch) | |
| tree | 66bd88546ee2ca7e88652eb1de31c11e3f014952 /arch/x86 | |
| parent | e3ec0d03bb1df69e8c9aba3eebba0690dc8e538b (diff) | |
x86: use EFI calling convention for efi_main on x86_64
UEFI specifies the calling convention used in Microsoft compilers;
first arguments of a function are passed in (%rcx, %rdx, %r8, %r9).
All other compilers use System V ABI by default, passing first integer
arguments of a function in (%rdi, %rsi, %rdx, %rcx, %r8, %r9).
These ABI also specify different sets of registers that must be preserved
across function calls (callee-saved).
GCC allows using the Microsoft calling convention by adding the ms_abi
attribute to a function declaration.
Current EFI implementation in U-Boot specifies EFIAPI for efi_main()
in the test apps but uses default calling convention in lib/efi.
Save efi_main() arguments in the startup code on x86_64;
use EFI calling convention for _relocate() on x86_64;
consistently use EFI calling convention for efi_main() everywhere.
Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/lib/crt0_x86_64_efi.S | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/arch/x86/lib/crt0_x86_64_efi.S b/arch/x86/lib/crt0_x86_64_efi.S index 989799fb4a..bb8d3cf8a9 100644 --- a/arch/x86/lib/crt0_x86_64_efi.S +++ b/arch/x86/lib/crt0_x86_64_efi.S @@ -3,7 +3,7 @@ * crt0-efi-x86_64.S - x86_64 EFI startup code. * Copyright (C) 1999 Hewlett-Packard Co. * Contributed by David Mosberger <davidm@hpl.hp.com>. - * Copyright (C) 2005 Intel Co. + * Copyright (C) 2005 Intel Corporation * Contributed by Fenghua Yu <fenghua.yu@intel.com>. * * All rights reserved. @@ -14,26 +14,28 @@ .globl _start _start: subq $8, %rsp + pushq %rcx pushq %rdx -0: - lea image_base(%rip), %rdi - lea _DYNAMIC(%rip), %rsi + mov %rcx, %r8 + mov %rdx, %r9 + + lea image_base(%rip), %rcx + lea _DYNAMIC(%rip), %rdx - popq %rcx - popq %rdx - pushq %rcx - pushq %rdx call _relocate - popq %rdi - popq %rsi + popq %rdx + popq %rcx + + testq %rax, %rax + jnz .exit call efi_main +.exit: addq $8, %rsp -.exit: ret /* |