[yocto] Selecting gcc version

[Chris Tapp]

On 25 Jun 2012, at 23:05, Khem Raj wrote:

> On Mon, Jun 25, 2012 at 2:57 PM, Chris Tapp <opensource at keylevel.com> wrote:
>> 
>> On 25 Jun 2012, at 22:52, Khem Raj wrote:
>> 
>>> On Mon, Jun 25, 2012 at 2:48 PM, Chris Tapp <opensource at keylevel.com> wrote:
>>>> Yes, it's 3.1.9 and it does compile. But the latest commits don't run when I build them (system displays a 'failed to execute kernel' error screen). Paul Eggleton has failed to get any to work when built using 4.7.0 (current master), so it does look as if this is compiler-related.
>>>> 
>>>> None of the commits appear to be likely to cause a change from 'good' to 'bad'.
>>>> 
>>> 
>>> can you tell me which commit is last good ?
>>> yes there are interaction between kernel and compiler
>>> sometimes kernel code has wrong expectation of gcc and when it gets
>>> fixed in gcc things dont work so in such cases kernel is fixed in some
>>> case kernel may expose real gcc bug too. Cant tell much unless its narrowed down
>> 
>> 
>> Last one I've got to work is https://github.com/raspberrypi/linux/commit/3fc65f9f291fb19cad434968a4a0f66ab749e637.
>> 
>> I've opened an issue at https://github.com/raspberrypi/linux/commit/3fc65f9f291fb19cad434968a4a0f66ab749e637 which also shows the firmware version that I know works, but that's probably not important here.
>> 
> 
> well there are options in .config being changed that can mean that now
> you could be waking up the sleeping dinosaurs.

Scary! (As my daughters would say).

>> I think I've got it building under 4.5.1 (Edison, as that was easier to do for a quick test).
> 
> OK


Well, that proves it's not the compiler. Still fails to boot, even though the toolchain that's supposed to work is 4.5.1. Does 32-bit / 64-bit host make a difference?

Chris Tapp

opensource at keylevel.com
www.keylevel.com