[yocto] [meta-raspberrypi][PATCH v2] linux-raspberrypi-rt: add

[Trevor Woerner]

On Thu 2017-01-05 @ 07:33:38 PM, Paul Barker wrote:
> On Thu,  5 Jan 2017 12:42:29 -0500
> Trevor Woerner <twoerner at gmail.com> wrote:
> 
> > Add an -rt kernel recipe for Raspberry Pi that includes the FIQ patch which
> > adds stability to the -rt kernel (with full preemption enabled) and is an
> > improvement to simply disabling FIQ on the kernel cmdline.
> > 
> > Signed-off-by: Trevor Woerner <twoerner at gmail.com>
> > ---
> > 
> > changes since v1:
> > 	- use "make savedefconfig" to generate the defconfig instead of just
> > 	  using the full .config
> > 
> >  .../0001-fix-dtbo-rules.patch                      |    44 +
> >  .../FIQ_PREEMPT_RT_on_raspi.patch                  |   310 +
> >  .../linux/linux-raspberrypi-rt-4.4/defconfig       |  1249 +
> >  .../patch-4.4.32-rt43.patch                        | 31403 +++++++++++++++++++
> >  recipes-kernel/linux/linux-raspberrypi-rt_4.4.bb   |    55 +
> >  5 files changed, 33061 insertions(+)
> >  create mode 100644 recipes-kernel/linux/linux-raspberrypi-rt-4.4/0001-fix-dtbo-rules.patch
> >  create mode 100644 recipes-kernel/linux/linux-raspberrypi-rt-4.4/FIQ_PREEMPT_RT_on_raspi.patch
> >  create mode 100644 recipes-kernel/linux/linux-raspberrypi-rt-4.4/defconfig
> >  create mode 100644 recipes-kernel/linux/linux-raspberrypi-rt-4.4/patch-4.4.32-rt43.patch
> >  create mode 100644 recipes-kernel/linux/linux-raspberrypi-rt_4.4.bb
> > 
> 
> Would it be possible to point SRC_URI at kernel.org [1] instead of
> including the whole patch in meta-raspberrypi? It feels a bit much to
> me to include a >1MB patch file.
> 
> [1]: https://www.kernel.org/pub/linux/kernel/projects/rt/4.4/older/patch-4.4.32-rt43.patch.gz

The "virgin" -rt patch from kernel.org doesn't apply cleanly. First off there
is a slight version mismatch and secondly this is the raspberrypi kernel, not
a pure upstream kernel.

Is there a way to patch a patch before it gets applied? If it could be
fetched from kernel.org then patched before applying that would be ideal!
The diff isn't that big; it's sad to have to provide a >1MB patch for such
a small tweak. I guess that's why the yocto kernels/patches have their own
repositories on yoctoproject.org?