[U-Boot] [PATCH 04/18] x86: efi: payload: Enforce toolchain to generate 64-bit EFI payload stub codes

[Alexander Graf]

On 11.06.18 04:34, Bin Meng wrote:
> On Mon, Jun 11, 2018 at 3:11 AM, Alexander Graf <agraf at suse.de> wrote:
>>
>>
>> On 10.06.18 15:25, Bin Meng wrote:
>>> Attempting to use a toolchain that is preconfigured to generate code
>>> for the 32-bit architecture (i386), for example, the i386-linux-gcc
>>> toolchain on kernel.org, to compile the 64-bit EFI payload does not
>>> build. This updates the makefile fragments to ensure '-m64' is passed
>>> to toolchain when building the 64-bit EFI payload stub codes.
>>>
>>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>>
>> Is there any sane reason to keep the split between EFI and U-Boot long
>> size alive? The x86_64 U-Boot port is getting along reasonably well from
>> what I can tell and 32bit UEFI implementations on 64-bit hosts are dying
>> out.
>>
> 
> I think you are mixing two type of things. U-Boot building as 32-bit
> or 64-bit is one thing. How to build U-Boot is another thing. This
> patch was to address the build.
> 
>> So can't we just remove all of that cruft altogether instead and just
>> have x86_64 U-Boot with 64bit EFI stub and i386 U-Boot with 32bit EFI
>> stub as only combinations?
>>
> 
> Some day once U-Boot x86_64 support is mature, we can consider that.
> Even if we only support 64-bit U-Boot as the 64-bit EFI payload, that
> does not mean i386-linux-gcc cannot be used. '-m64' is required to
> pass to such toolchain to cross-compile 64-bit codes correctly.

Yes, but then all of this would be unconditional for the full code base
and not depend on CONFIG_EFI_STUB_64BIT at all :).

I'm just wary that the efi payload code is quite hard to follow with all
the combinations of 32/64 payload/u-boot bitnesses.


Alex