The special kernel source code of ubuntu for RT_PREEMPT

QiayuanLiao

I want to patch the RT_PREEMPT to ubuntu kernel, but I can't find the kernel source code with the special support of GPIO, SPI.

DCleri

As described in our wiki: https://wiki.up-community.org/Ubuntu

You can find the sources of the Ubuntu kernel for Ubuntu 16.04 and 18.04 from the launchpad repository for UP:
https://launchpad.net/~ubilinux/+archive/ubuntu/up/+packages

in particular for Ubuntu 16.04:
linux-source-4.15.0_4.15.0-37.40~upboard03_all.deb

and for Ubuntu 18.04:
linux-source-4.15.0_4.15.0-37.40_upboard04_all.deb

QiayuanLiao

@DCleri said:
As described in our wiki: https://wiki.up-community.org/Ubuntu

You can find the sources of the Ubuntu kernel for Ubuntu 16.04 and 18.04 from the launchpad repository for UP:
https://launchpad.net/~ubilinux/+archive/ubuntu/up/+packages

in particular for Ubuntu 16.04:
linux-source-4.15.0_4.15.0-37.40~upboard03_all.deb

and for Ubuntu 18.04:
linux-source-4.15.0_4.15.0-37.40_upboard04_all.deb

Ops! I didn't note that there is some source code in the launchpad repository. There isn't any RT_PREEMPT patch for 4.15 kernel. Can I use "linux-upboard - 4.4.0-2.12" or " linux-upboard-lts-xenial - 4.4.0-2.6~14.04.1"? What is the difference between then?

DCleri

the 4.4 has not been updated anymore and it doesn't support UP Squared or newer boards.

For kernel 4.15 RT_PREEMPT is an option in the kernel that you can enable at build time (in 4.4 or older you needed to patch the kernel).