Hei hei,

On Thu, Nov 11, 2021 at 02:39:00PM +0000, Anton Kornilevsky wrote:
> I have been tasked with rebuilding a linux kernal for a board that
> is using the AT91SAM9261 MCU.

Which is still supported by recent Linux Kernel AFAIK.

> The buildroot support for this MCU has been dropped sometimes back in 2015, 

Can you point to some actual commits?

> and I was unable to rebuild the kernal using the last supported
> version of buildroot, due to an error related to the integrity of
> the zipfile containing the sam-ba utility. I seems like the older
> sam-ba utility versions are no longer to be found on microchips
> servers.

I might have those lying around somewhere, but you don't need those
for running on the target anyways, do you?

> How would one go about adding support to a variant of an MCU that is
> already supported by Buildroot? Is this even possible?

I just looked briefly over the defconfigs in buildroot's 'configs'
folder and at91sam9g20dfc_defconfig and at91sam9260eknf_defconfig
should be from the same at91 family. That should be a good start to
come up with a toolchain at least?

For building a recent kernel, at91_dt_defconfig in kernel tree should
give you a starting point?

Good luck!
Alex

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