If a kernel compiles, will it work?

[bholland]

Hi All,

 

I am not new to kernel building. I have been building kernels since the early days of Gentoo. Kernels on boards however, is something a bit different.  I have an roc-rk3328-cc but this would be applicable to a variety of boards. 

 

Right now Firefly has their 4.* kernel at 4.4.114. I guess at some point that was what they went with. 

 

The current kernel is at about 4.15.14. I couldn't figure out how to patch from 4.4.114 to 4.15.14 (if you could provide help with that, please do so) so I downloaded the tarball and extracted it into the firefly's git directory. 

 

What should have happened was any kernel related file got updated to 4.15.14 but none of the configuration files were overwritten. It seems like firmware gets baked into the system image later and firefly provides the SoC+firmware anyway. I made the kernel last night and everything seemed to compile. I even have modules, though I am still at a loss for how to install modules within a u-boot system. 

 

Anyway. Did I do something incredibly stupid that will result in an unstable kernel for my board or was this a more reasonable set of steps to take?

 

Thanks!

[Xalius]

You have to be aware that the 4.4.x kernel series is the BSP kernel maintained by Rockchip (mostly based on Linaro LTS releases), which is different from mainline Linux with regards to drivers and other patches.

 

RK's upstream for BSP Linux is here: https://github.com/rockchip-linux

And you get all the info from: http://opensource.rock-chips.com/wiki_Main_Page

 

Mainline Linux is developed by the community, but RK supports it too with patches: https://patchwork.kernel.org/project/linux-rockchip/list/

 

You have to decide what kernel you want to run on your board, BSP is generally a bit more complete, for example it has VPU drivers, see status matrix here:

 

http://opensource.rock-chips.com/wiki_Status_Matrix

 

So you can't just patch your 4.4.x codebase up to current mainline, you have to work from the upstream repository...

[bholland]

3 hours ago, Xalius said:

You have to be aware that the 4.4.x kernel series is the BSP kernel maintained by Rockchip (mostly based on Linaro LTS releases), which is different from mainline Linux with regards to drivers and other patches.

 

RK's upstream for BSP Linux is here: https://github.com/rockchip-linux

And you get all the info from: http://opensource.rock-chips.com/wiki_Main_Page

 

Mainline Linux is developed by the community, but RK supports it too with patches: https://patchwork.kernel.org/project/linux-rockchip/list/

 

You have to decide what kernel you want to run on your board, BSP is generally a bit more complete, for example it has VPU drivers, see status matrix here:

 

http://opensource.rock-chips.com/wiki_Status_Matrix

 

So you can't just patch your 4.4.x codebase up to current mainline, you have to work from the upstream repository...

 

Awesome! Thank you so much. I am a bit surprised that open source drivers haven't made it into the stable kernel yet. This was exactly what I was afraid of. I noticed in the kernel options that Rockchip as a type of ARM was natively supported but I didn't think about dedicated drivers. 

 

Given this, I will have to revert back to the 4.4.114 kernel. Am I missing anything really important between the 4.4 and the 4.15 branch? That question might be too complex or too unknown but thank you. This is hugely helpful. I have some more reading to do. 

 

 

[bholland]

Oh. And one last really stupid and trivial question. Should I pull from this git repo rather than the firefly ones?

 

Thanks!