Real-Time Kernel with Orange Pi 4 LTS

royka wrote:

Besides patching you should still choose full realtime in the config. After entering "make menuconfig" => General setup => Preemption Model => Fully preemptible kernel

Here are the rt config settings that works best for the rk3588:
github.com/orangepi-xunlong/linux-orange...s/rockchip_rt.config
 

Thnks, I've done all that but didnt work. I chose fully preemptible kernel.
my problem is after compilation, and after installing the deb file of rt compiled kernel, the kernel doesn't switch to the rt one and still boot with the old kernel. and also I manually changed the boot.cmd file in the boot directory, after doing this the kernel doesnt boot up at all and just stuck in that stage.
by the way, my orange pi 4 lts has rk3399 not rk3588.

Check with "ls -l /boot" if all links are correct. With Armbian for example the Image file is a link to the used kernel. To relink you can use "sudo ln -sf your-rt-kernel Image" and also check for the uinitrd link and to use the right dtb for that kernel version.

I saw that it's a rk3399 indeed, but here it also worked great for a s912 sbc so it might be a good base for yours too.

royka post=314868 userid=31446Check with "ls -l /boot" if all links are correct. With Armbian for example the Image file is a link to the used kernel. To relink you can use "sudo ln -sf your-rt-kernel Image" and also check for the uinitrd link and to use the right dtb for that kernel version.

I saw that it's a rk3399 indeed, but here it also worked great for a s912 sbc so it might be a good base for yours too.

 

Thanks, I've tried to relink the files in boot directory to my new kernel files, still same problem.
In the source that I compiled from, I noticed that there is no dts and dtsi files and other related files for rk3399 in that source. can it be the problem for not booting after compilation?
if it can be, how can I solve this problem?
is there any other source besides kernel.org?

I tried another thing too, I used another sources like rockchip and orangepi-build. but whenever I wanna patch the real-time patch (got from kernel.org), it fails and says there are conflicts and incompatibility/

royka wrote:

Check with "ls -l /boot" if all links are correct. With Armbian for example the Image file is a link to the used kernel. To relink you can use "sudo ln -sf your-rt-kernel Image" and also check for the uinitrd link and to use the right dtb for that kernel version.

I saw that it's a rk3399 indeed, but here it also worked great for a s912 sbc so it might be a good base for yours too.

 

while a go you've provided a rt kernel for my orange pi 5 plus. can u do the same for this one (orange pi 4 lts) ? i mean a real-time 5.10.43 kernel for rk3399?

At least for the rk3588 the dtb version must match with the kernel version so I assume it's the same with yours. In this case it might be easier to create an image with the Armbian build system, just put the rt patch in the right folder, for example patch/kernel/archive/rockchip64-6.9 and start with ./compile and choose that you want to see the kernel config before you'll compile it.

Although they only support Linux 6.6, 6.9 and 6.12 (which don't need a rt patch). But if for some reason you need an older kernel you could just find an image with the same version kernel you've compiled and copy that dtb.

Is there a reason that you need specific that kernel version?