Re: [PATCH v2] Ensure that MIPS target code is compiled for the O32 ABI.

[Mark H Weaver <mhw@netris.org>]

"Vladimir 'φ-coder/phcoder' Serbinenko" <phcoder@gmail.com> writes:

> On 23.08.2015 23:50, Mark H Weaver wrote:
>> Include -mabi=32 in CFLAGS_PLATFORM and CCASFLAGS_PLATFORM to compile
>> code for the O32 ABI when targetting MIPS, since the MIPS assembly code
>> in GRUB assumes this.
> Could you be more precise where we assume this?

Well, to begin with, most of the MIPS assembly code in GRUB uses the
MIPS register names such as $tN, $sN, $aN, $vN, etc.  Such code is
rejected by the assembler unless the O32 ABI is being used, which makes
sense since those names are based on the registers' roles in the O32
ABI.

In addition, I guess that any MIPS assembly code in *.S that is called
by C (or calls into C) will need to be adjusted to use the calling
conventions of the ABI in use (N32 or N64).  There may be other issues
as well; I haven't researched it.

> Why not fix the assembly instead?

If someone wants to do that job, I'd be pleased, but I don't have time
to do it.  I have too many other more important things to work on, and
not enough time.  Too few people are working on non-Intel platforms,
leaving most of the work on both the MIPS and ARMHF ports of GNU Guix to
me.  Many other important packages still need to be fixed on both MIPS
and ARMHF, whereas I have GRUB working well.

     Regards,
       Mark