[U-Boot] [RFC PATCH 2/4] OMAP3+: fix issues with Thumb build

Aneesh V aneesh at ti.com
Tue Feb 7 08:49:27 CET 2012


On Tuesday 07 February 2012 02:36 AM, Albert ARIBAUD wrote:
> Le 06/02/2012 12:37, Aneesh V a écrit :
>> When U-Boot/SPL is built using the Thumb instruction set the
>> toolchain has a potential issue with weakly linked symbols.
>> If a function has a weakly linked default implementation in C
>> and a real implementation in assembly GCC is confused about the
>> instruction set of the assembly implementation. As a result
>> the assembly function that is built in ARM is executed as
>> if it is Thumb. This results in a crash.
>>
>> We need to investigate further to see if this is a toolchain
>> issue or an issue with our usage of it. In the meanwhile, we
>> can workaround the issue by having both the weakly linked alias
>> and the real implementation in C.
>
> I would tend to NAK a patch submission where an issue is known and
> investigation is considered but is actually bypassed by a workaround.
> These tend to turn from 'temporary fix' to 'old crust' with time,
> because there is no incentive for a better solution when the quick fix
> "works, after all".

Fair enough. I did actually report this to Linaro a long time back and
they had started looking into it. But then I couldn't support it
further due to some other activities that pre-empted it. I plan to
revive that thread now and I shall copy you on that. But in case the
issue is root-caused and the problem is indeed with the tool-chain,
then I hope you will accept this patch at least in the interest of
backward compatibility.

Also, I hope you don't object to taking the first patch, after fixing
the comments?

Thanks,
Aneesh


More information about the U-Boot mailing list