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

[Heinrich Schuchardt]

On 05/25/2018 11:28 PM, Ivan Gorinov wrote:
> Save the arguments passed in %rcx and %rdx for efi_main() on x86_64;
> consistently use EFI calling convention for efi_main().
> 
> Signed-off-by: Ivan Gorinov <ivan.gorinov at intel.com>

One big difference between the ms_abi and the sysv_abi calling
convention is the set of volatile registers. So shouldn't _relocate()
also be declared as EFIAPI to ensure that we do not mess up the callers
registers?

Best regards

Heinrich

> ---
>  arch/x86/lib/crt0_x86_64_efi.S | 8 ++++----
>  lib/efi/efi_app.c              | 3 ++-
>  lib/efi/efi_stub.c             | 3 ++-
>  3 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/lib/crt0_x86_64_efi.S b/arch/x86/lib/crt0_x86_64_efi.S
> index 989799f..2d53d1b 100644
> --- a/arch/x86/lib/crt0_x86_64_efi.S
> +++ b/arch/x86/lib/crt0_x86_64_efi.S
> @@ -16,19 +16,19 @@ _start:
>  	subq $8, %rsp
>  	pushq %rcx
>  	pushq %rdx
> +	pushq %rsi
> +	pushq %rdi
>  
>  0:
>  	lea image_base(%rip), %rdi
>  	lea _DYNAMIC(%rip), %rsi
>  
> -	popq %rcx
> -	popq %rdx
> -	pushq %rcx
> -	pushq %rdx
>  	call _relocate
>  
>  	popq %rdi
>  	popq %rsi
> +	popq %rdx
> +	popq %rcx
>  
>  	call efi_main
>  	addq $8, %rsp
> diff --git a/lib/efi/efi_app.c b/lib/efi/efi_app.c
> index c828093..3eb8eeb 100644
> --- a/lib/efi/efi_app.c
> +++ b/lib/efi/efi_app.c
> @@ -96,7 +96,8 @@ static void free_memory(struct efi_priv *priv)
>   * U-Boot. If it returns, EFI will continue. Another way to get back to EFI
>   * is via reset_cpu().
>   */
> -efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
> +efi_status_t EFIAPI efi_main(efi_handle_t image,
> +			     struct efi_system_table *sys_table)
>  {
>  	struct efi_priv local_priv, *priv = &local_priv;
>  	efi_status_t ret;
> diff --git a/lib/efi/efi_stub.c b/lib/efi/efi_stub.c
> index 3138739..399d16b 100644
> --- a/lib/efi/efi_stub.c
> +++ b/lib/efi/efi_stub.c
> @@ -268,7 +268,8 @@ static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type,
>   * This function is called by our EFI start-up code. It handles running
>   * U-Boot. If it returns, EFI will continue.
>   */
> -efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
> +efi_status_t EFIAPI efi_main(efi_handle_t image,
> +			     struct efi_system_table *sys_table)
>  {
>  	struct efi_priv local_priv, *priv = &local_priv;
>  	struct efi_boot_services *boot = sys_table->boottime;
>