[U-Boot] [PATCH 1/2] tegra2: Always build with USE_PRIVATE_LIBGCC=yes.

[Stephen Warren]

On 01/05/2012 01:42 PM, Simon Glass wrote:
> Hi,
> 
> On Thu, Jan 5, 2012 at 12:17 PM, Wolfgang Denk <wd at denx.de> wrote:
>> Dear Stephen Warren,
>>
>> In message <4F05FCBD.2040207 at nvidia.com> you wrote:
>>>
>>>> No, this is NOT a solution, it is a workaround for an inappropriate
>>>> toolchain.  If you want to build code for an armv4t system, you must
>>>> use a tool chain that supports it.
>>>
>>> But we don't want to generate code for ARMv4 in general, but rather
>>
>> Then just turn on the ARMv4 specific options (-march=armv4t -mno-thumb
>> -mthumb-interwork -mtune=arm920t ???) for the files that need it.

That's exactly what we've already done, but that doesn't affect code
that gets pulled in from libgcc, which is what USE_PRIVATE_LIBGCC
affects IIUC.

>> But as soon as any of these files liks code from libgcc you have to
>> decide.
> 
> Perhaps we could adjust Tegra's config.mk to use ARMv4T when not
> building with the private libgcc?

I believe the relevant U-Boot source files are already built for ARMv4T,
it's just libgcc that's the issue.

>>> ARMv7 as the toolchain does. Only a tiny part of the code needs to be
>>> built for ARMv4, and in general we want to benefit from using ARMv7.
>>
>> Then you should probably still link against a ARMv4 specific libgcc.
>>
>> If you were building U-Boot's libgcc code with optimization set for
>> ARMv7 this would not fix anything.
> 
> It might be possible to specify ARMv4T on the link flags and have it
> pick up the v4T library, even if nearly everything else is ARMv7?

I don't think we use any multilib toolchains, so I don't think that's
possible.

-- 
nvpublic