real time linux-libre kernel?

[Ali Gunduz]

On Sun, Aug 23, 2009 at 9:22 PM, wayne<wayne at jawnee.org> wrote:

[...]

>     could anyone point me in the right direction for where to find a real
> time linux-libre kernel, in particular for gNewSense, Gentoo, and Debian?
> if nothing exists, is there a place to start learning how i could build a
> linux-libre real time kernel to share with the community?

Realtime branch of the kernel Linux is maintained as a patchset to
certain Linux releases. You can find these patches at
http://www.kernel.org/pub/linux/kernel/projects/rt/. The latest stable
kernel release supported by -rt patchline seems to be 2.6.29.6.

I have never deblobbed or compiled or used a realtime kernel, but my
guess is you could follow these steps:

1) Download the vanilla 2.6.29.6 kernel from
http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.29.6.tar.bz2 and
uncompress it

2) Download the corrsponding realtime patch from
http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.29.6-rt23.bz2
and apply this patch to the kernel source code (you can do a web
search to learn how to apply patches.)

3) Deblob the resulting nonfree realtime kernel with
http://www.fsfla.org/~lxoliva/fsfla/linux-libre/releases/2.6.29.6-libre1/deblob-2.6.29

4) Now, you should have a free realtime kernel source. After this
point, you can simply follow my tutorial at
http://aligunduz.org/articles/buildkernel.html to build a kernel
installation package for gNewSense. Make sure to enable CONFIG_PREEMPT
and CONFIG_PREEMPT_RT during the configuration (the part where you use
menuconfig or xconfig or gconfig).

Beware, though, I'm presuming that the -rt patch isn't bringing in
anything non-free that the deblob script can't handle.

Happy Hacking

Ali Gunduz