Development board for vanilla kernel

[mutinifni]

I am looking for an ARM development board which supports mainline Linux kernel. I started out by looking at Raspberry Pi (3) and noticed that it requires the patched R-Pi kernel version to support Broadcom 2837 SoC.

Are there any boards, including old ones, that are fully compatible with the mainline Linux kernel? Another requirement I am looking at is that timers be local per processor core, but I believe this is indeed the case with Cortex-A53 processors at the least.

Thanks.

[jamesh]

I'm not sure there are any in mainline. You could take a look at the ARM devices supported in the mainline code to see if anything pops up.

Generally, ARM boards are all a bit different, so most require a patched kernel.

Note, that a lot of effort is going in to getting Pi's in mainline. Check out the RPF github page for references to that. Device tre is also helping with this.

Just out of interest, why is a patched kernel inappropriate. In most respects the Pi kernel is pretty vanilla.

[ejolson]

Just out of interest, why is a patched kernel inappropriate. In most respects the Pi kernel is pretty vanilla.

A patch set can get out of date and no longer apply to current kernels. At the present time most vendor-patched kernels for ARM based computers are 32 bit and many are stuck at pre 4.x versions, which don't have full btrfs support among other things.

Also, since there are pretty strict quality requirements for code to be included in the mainline kernel, it is plausible that a vendor patch is of low quality if it is not accepted upstream.

Since vendors establish their own reputations over time, the above concerns may be more important in some cases than in others. In my opinion, except for not being 64 bit, the foundation supplied kernels are up to date and of high qualify.

[mutinifni]

I checked the current vanilla kernel device tree and found a file called bcm2836-rpi-2-b.dts (https://github.com/torvalds/linux/blob/ ... pi-2-b.dts).

Does this mean this vanilla kernel can be compiled for RPi-2b? Even so, it is a problem because it uses the Cortex-A7 processor which does not implement private timers (per-core timers). These processors use only a Generic Timer (http://infocenter.arm.com/help/index.js ... 16107.html) which if I understand correctly, is a "global" timer.

I do not see such a file available for Raspberry Pi 3, presently.

[Aydan]

I am looking for an ARM development board which supports mainline Linux kernel. I started out by looking at Raspberry Pi (3) and noticed that it requires the patched R-Pi kernel version to support Broadcom 2837 SoC.

Are there any boards, including old ones, that are fully compatible with the mainline Linux kernel? Another requirement I am looking at is that timers be local per processor core, but I believe this is indeed the case with Cortex-A53 processors at the least.

Thanks.

The imx6 SoC is supposed to be supported by vanilla kernels. The Solidrun Cubox-i series uses those, and I have two Cuboxes. Haven't tried to use vanilla kernel yet, but it's on the list of things to do.

Regards
Aydan