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

[Simon Glass]

Hi Bin,

On 14 January 2017 at 06:32, Bin Meng <bmeng.cn at gmail.com> wrote:
> 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?

OK will add a TODO. There's no reason to not support that that I can think of.

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

Regards,
Simon