[yocto] [Pyro] Multiple toolchains

[Alexander Kanavin]

On 01/17/2018 05:59 PM, philippe gislard wrote:
> We are updating our BSP from Krogoth to Pyro.
> We are using a kernel designed and patched specifically for our
> hardware (3.10.40) that does not compile with GCC 5.x or GCC6.x.
> AFAIK, Pyro is qualified with GCC 5.x and GCC6.x (not with earlier versions).
> 
> What is the easiest way to use two toolchains?
> - GCC 4.9 for the kernel.
> - GCC 6.3 for the other packages.

YP releases do not support this scenario. You might just about get away 
with it, if you add the recipes for the old gcc, and set KERNEL_CC in 
kernel-arch.bbclass to point to them, but you're on your own here.

The easiest way - in the long run - is to find a way to forward port the 
kernel patches to a newer, supported kernel release (and maybe even 
upstream them); also explain the concept of 'technical debt' to your 
management:

https://en.wikipedia.org/wiki/Technical_debt

Alex