[U-Boot] [PATCH v2 46/63] x86: Don't build call64 and setjmp on 64-bit

[Bin Meng]

Hi Simon,

On Sun, Nov 20, 2016 at 4:25 AM, Simon Glass <sjg at chromium.org> wrote:
> These are currently not supported. Calling 64-bit code from 64-bit U-Boot is
> much simpler, so this code is not needed. setjmp() is not yet implemented for
> 64-bit.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> Changes in v2: None
>
>  arch/x86/cpu/Makefile | 6 +++++-
>  arch/x86/lib/bootm.c  | 2 ++
>  2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
> index 7f89ff0..f0135a7 100644
> --- a/arch/x86/cpu/Makefile
> +++ b/arch/x86/cpu/Makefile
> @@ -14,7 +14,11 @@ else
>  extra-y        = start.o
>  endif
>  extra-$(CONFIG_$(SPL_)X86_16BIT_INIT) += resetvec.o start16.o
> -obj-y  += cpu.o cpu_x86.o call64.o setjmp.o
> +ifndef CONFIG_$(SPL_)X86_64
> +obj-y  += call64.o setjmp.o
> +endif
> +
> +obj-y  += cpu.o cpu_x86.o
>
>  AFLAGS_REMOVE_call32.o := -mregparm=3 \
>         $(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
> diff --git a/arch/x86/lib/bootm.c b/arch/x86/lib/bootm.c
> index 80fadef..4ac01a3 100644
> --- a/arch/x86/lib/bootm.c
> +++ b/arch/x86/lib/bootm.c
> @@ -150,7 +150,9 @@ int boot_linux_kernel(ulong setup_base, ulong load_address, bool image_64bit)
>                         puts("Cannot boot 64-bit kernel on 32-bit machine\n");
>                         return -EFAULT;
>                 }
> +#if !CONFIG_IS_ENABLED(X86_64)
>                 return cpu_jump_to_64bit(setup_base, load_address);

Can we add a comment here mentioning booting 64-bit kernel is not
supported? Also, do we plan to support 64-bit U-Boot booting 32-bit
kernel? I guess no?

> +#endif
>         } else {
>                 /*
>                 * Set %ebx, %ebp, and %edi to 0, %esi to point to the
> --

Regards,
Bin