[U-Boot] [PATCH v3] x86: use EFI calling convention for efi_main on x86_64

Ivan Gorinov ivan.gorinov at intel.com
Thu May 31 18:46:05 UTC 2018


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.
The arguments of efi_main() are also passed as unused arguments to the
_relocate() function.

Save efi_main() arguments in the startup code on x86_64;
use EFI calling convention for _relocate() on x86_64;
remove unused _relocate() arguments;
consistently use EFI calling convention for efi_main() everywhere.

v3:
  Updated patch description.

v2:
  Added EFIABI to _relocate() declaration.


Ivan Gorinov (1):
  x86: use EFI calling convention for efi_main on x86_64

 arch/x86/lib/crt0_x86_64_efi.S  | 21 ++++++++++-----------
 arch/x86/lib/reloc_x86_64_efi.c |  3 +--
 lib/efi/efi_app.c               |  3 ++-
 lib/efi/efi_stub.c              |  3 ++-
 4 files changed, 15 insertions(+), 15 deletions(-)

-- 
2.7.4



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