Re: [PATCH v2] grub-core: Build fixes for i386

[John Paul Adrian Glaubitz]

Hi Daniel!

On 5/18/21 4:26 PM, Daniel Kiper wrote:
> When I was looking at the issue first time I thought in the same way.
> Though after some thinking I realized that it is perfectly valid to
> start 64-bit kernel from 32-bit bootloader which was build in 32-bit
> environment. So, I think it makes sense to take that patch, which is not
> very complicated and does not introduce anything which did not exist
> earlier in the relocator64.S, even a such scenario is not very common
> today.

But this is about the toolchain, isn't it? Shouldn't even a 32-bit x86
toolchain be able to build 64-bit code?

I just checked standard binutils on a 32-bit Debian system and both the
assembler and the linker support 64-bit targets:

(sid_i386-dchroot)glaubitz@barriere:~$ as --help|grep 64
  --32/--64/--x32         generate 32bit/64bit/x32 code
                           generic32, generic64, i386, i486, i586, i686,
                           pconfig, waitpkg, cldemote, movdiri, movdir64b,
                           nomovdiri, nomovdir64b, noavx512_bf16,
                           generic32, generic64, i8086, i186, i286, i386, i486,
  -mamd64                 accept only AMD64 ISA [default]
  -mintel64               accept only Intel64 ISA
(sid_i386-dchroot)glaubitz@barriere:~$

(sid_i386-dchroot)glaubitz@barriere:~$ ld --help|grep supported
ld: supported targets: elf32-i386 elf32-iamcu pei-i386 elf32-little elf32-big 
elf64-x86-64 elf32-x86-64 pei-x86-64 elf64-l1om elf64-k1om elf64-little 
elf64-big pe-x86-64 pe-bigobj-x86-64 pe-i386 srec symbolsrec verilog tekhex 
binary ihex plugin trad-core
ld: supported emulations: elf_i386 elf_iamcu elf_x86_64 elf32_x86_64 elf_l1om 
elf_k1om i386pep i386pe
(sid_i386-dchroot)glaubitz@barriere:~$

So I'm not sure what kind of host system we are talking about here? This looks
more like a configuration issue of the distribution in question which 
deliberately
builds its 32-bit toolchain without 64-bit support.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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