On Mon, Jan 24, 2022 at 7:04 AM Mike Galbraith <efault@xxxxxx> wrote: > > On Sun, 2022-01-23 at 09:40 -0500, gene heskett wrote: > > On Friday, December 24, 2021 9:16:57 PM EST you wrote: > > > On Thu, 2021-12-23 at 17:13 +0100, Sebastian Andrzej Siewior wrote: > > > > Dear RT folks! > > > > > > > > I'm pleased to announce the v5.16-rc6-rt12 patch set. > > > > > > > Changes since v5.16-rc6-rt11: > > > ... > > > > > > > - The "Memory controller" (CONFIG_MEMCG) can be enabled again. > > > > > > FWIW, LTP testcases pass on rpi4 and x86_64 boxen with no gripeage. > > > Full LTP with maximally bloated config was as uninteresting as one can > > > hope for. > > > . > > > > Unforch and after many try's, I can't get it to reboot when installed, > > sorta, on an rpi4b. > > > > I say sorta, because no matter how many times I rebuild it, the build > > does not generate an arch/arm/boot/dts/overlays directory. The build > > itself is error free. > > > > The raspi kernel build instructions from their somewhat dated wiki also > > say to use the bcm2711_defconfig, but it does not now exist in a git > > clone. And a hwinfo of the rpi4b says I should use the bcm2835_defconfig > > for a starter .config. > > > > Is there any hope of making this work? > > Sure. Given bcm2711_defconfig is missing, sounds like you're trying to > build patched up kernel.org source. You can do that, works fine for > me, and I know jack diddly spit about cute little arm gizmos ;-) but > you're better off patching up source from... > > git clone https://github.com/raspberrypi/linux.git > > ...instead, which has a large pile of not yet upstreamed rpi patches. > Just checkout the rpi-5.16.y branch and apply the 5.16-rt patch set. > There you'll find that bcm2711_defconfig you were looking for. > > I build on my desktop box, rpi4 being every bit as fast as you'd expect > something that dinky to be, then nfs mount from rpi4 and sudo make > modules_install dtbs_install install. Edit /boot/config.txt, reboot, > and presto, you too will be ready to have any unrealistic x86_64 based > expectations you may have thoroughly dashed by cyclictest numbers :) > > -Mike Based on Mike's excellent advice earlier this month, I got 5.10 running nicely on a pi 4 with the RT patchset. https://github.com/frc971/linux/tree/frc971-5.10-pi4-rt is our tree. We are using it for running 2 khz estimation algorithms for robots. I picked the current stable kernel version in the released rootfs instead of being as adventurous as Mike and running a newer kernel. There's a pretty good howto from the raspberry pi folks about how to build a kernel which I used to deploy it. https://www.raspberrypi.com/documentation/computers/linux_kernel.html#cross-compiling-the-kernel Austin
