P1020 custom board - Linux kernel selection / RT

[lukaszzemla]

We plan to start using Linux in our projects based on P1020. The HW design was initially based on P1020RDB-PC, but in practice it went quite far for original one. For sure at least PREEMPT_RT will be required, but most probably we will need Xenomai. I'd like to understand more the available choices in the terms of Linux source.

What is the best source of Linux for P1020?

I assume the kernel offered by Freescale QorIQ SDK is the best in the terms of compatibility with P1020 and support for HW features. It also offers 3.12.x PREEMPT_RT kernel out of box. However it is quite old kernel, additionally we were not able to patch it by Xenomai (no available patch for 3.12. Unfortunately 3.14 did not work). How long that Freescale 3.12 kernel is expected to be maintained? Are there any plans to switch to more recent versions?

We thought also about using one of most recent vanilla kernels (it is easy to apply Xenomai patches). Assumption is that all HW specific features from Freescale are being continuously integrated to mainline vanilla kernel. Is it a valid assumption? How does it look in practice? How good in the terms of support of P1020/T1020 is vanilla 4.1?

Thank you in advance,

Lukasz

[lukaszzemla]

I have checked GitHub - Freescale/linux-fslc: Linux kernel source tree . Unfortunately it is not a solution for me, because:

• Xenomai patch cannot be applied on that (it fails)
• for unknown reasons it does not work with my eMMC device. More details: P1020 and eMMC - different behavior on different kernels

[lukaszzemla]

When do you plan to release next SDK?

Is there any place where FSL 4.1 kernel is available?

[r8070z]

Did you check Freescale · GitHub?

There is Linux kernel source tree forked from torvalds/linux 
GitHub - Freescale/linux-fslc: Linux kernel source tree

Now it is 4.1

[scottwood]

That repository appears to be for i.MX.  I doubt there's anything relevant to P1020 in there.  For this chip I recommend using the upstream kernel unless there's something specific you know you need from the SDK.

[scottwood]

It's unfortunately not yet true that "all HW specific features from Freescale are being continuously integrated to mainline vanilla kernel" but the main problems are with newer chips.  P1020 should work well with upstream kernels, though I can't guarantee that it supports every single hardware feature that the SDK does.

The next SDK release will be based on 4.1.