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.
v4: Keeping .exit label in x86_64 startup code; Also removed the unused _relocate() arguments for arm, x86, riscv.
v3: Updated patch description.
v2: Added EFIABI to _relocate() declaration.
Ivan Gorinov (4): x86: use EFI calling convention for efi_main on x86_64 arm: Remove unused _relocate arguments x86: Remove unused _relocate arguments riscv: Remove unused _relocate arguments
arch/arm/lib/crt0_aarch64_efi.S | 2 -- arch/arm/lib/crt0_arm_efi.S | 2 -- arch/arm/lib/reloc_aarch64_efi.c | 3 +-- arch/arm/lib/reloc_arm_efi.c | 3 +-- arch/riscv/lib/reloc_riscv_efi.c | 3 +-- arch/x86/lib/crt0_x86_64_efi.S | 21 ++++++++++----------- arch/x86/lib/reloc_ia32_efi.c | 3 +-- arch/x86/lib/reloc_x86_64_efi.c | 3 +-- lib/efi/efi_app.c | 3 ++- lib/efi/efi_stub.c | 3 ++- 10 files changed, 19 insertions(+), 27 deletions(-)