Maverick toolchain

[Matthias Klose]

On 21.07.2010 10:00, Robbie Williamson wrote:
> On Tue, 2010-07-20 at 21:45 +0200, Matthias Klose wrote:
>> On 20.07.2010 21:03, Mark Shuttleworth wrote:
>>> On 20/07/10 16:53, Robbie Williamson wrote:
>>>> On 20/07/10 12:25, Matthias Klose wrote:
>>>>
>>>>> I suggest to enable the Linaro GCC on amd64, i386 and powerpc as well,
>>>>> given the  comittment of the Linaro toolchain working group to
>>>>> addressing potential regressions on amd64 and i386 too.
>>>>>
>>>>
>>>> Doko, thank you for the feedback. Given that we are midway through the
>>>> release cycle, and that we have not done *any* system testing with the
>>>> amd64 and i386 packages/kernels built using this toolchain, I'm
>>>> concerned with making this change now.  As acting release manager, I
>>>> propose we move to Linaro's GCC now for the armel flavor of Ubuntu
>>>> 10.10, and make the change for amd64 and i386 in 11.04.
>>>>
>>>
>>> I don't want to rock the RM boat, especially since I'm responsible for
>>> the tighter timelines of 10.10, but this is a change which has been in
>>> play since UDS, has had extensive analysis and a full rebuild test with
>>> detailed examination. It's certainly not a new thing being raised at
>>> this stage, and we agreed not to press the issue earlier only because
>>> the offer was made to do the testing and decide then. It would be wrong
>>> to have made that offer and then decline to make the change even after
>>> the testing comes back as favourably as it did - next time, folks won't
>>> be as willing to leave the door open for extended analysis.
>>>
>>> It's also quite material to the collaboration of Linaro and the rest of
>>> the platform.
>>
>> Afaiu the biggest concern to the Linaro GCC is it's use for the kernel build.
>> Apparently nobody including myself did explicitly communicate to the kernel team
>> about the decision in the arm toolchain session (arm-m-tool-chain-selection).
> In addition, nothing has ever been posted to ubuntu-devel or
> ubuntu-devel-discuss about this, so I feel it may catch many Ubuntu
> contributors and our derivatives off guard.  I know this was discussed
> at UDS, but I don't know if most thought a session titled "ARM Toolchain
> Selection" [1] encompassed toolchain selection for non-ARM architectures
> as well.
>
> [1] https://wiki.ubuntu.com/Specs/M/ARMToolChainSelection
>
>>
>> If this is the only major concern I'd like to propose to use the gcc-4.4-fsf
>> packages (which still need landing in maverick) to build the kernel (shipping
>> the gcc-4.4-fsf binary with the name kgcc on the CDs).
> Please talk to the kernel team and see what they say.

gcc-4.4-fsf packages are now available for amd64, i386 (armel still building) in
https://launchpad.net/~ubuntu-toolchain-r/+archive/ppa/+packages, providing a 
binary `kgcc'.  This is currently a build with multilibs disabled. I'll update 
the archive with a multilib'd compiler after the armel build is finished. If we 
decide to upload this to maverick, this will provide at least a short term 
solution for the Ubuntu/ARM team to build kernel images for the next alpha.

   Matthias