[Buildroot] About using ti-gfx package with cutom kernel

[Spenser Gilliland]

On Thu, Jul 11, 2013 at 10:06 AM, Sinan Akpolat <sinan at linkas.com.tr> wrote:
> Hi,
>
> I want to thank Spenser for his great work on TI's PowerVR driver package.
>
> I couldn't test it yet and I need to ask something about that.
>
> The package needs Linux kernel to be selected. However I'm using a custom
> kernel provided by the board manufacturer. How can I make buildroot use that
> kernel? Or what is the correct way?
>
> Should I copy my custom kernel directory to output/build and change version
> to suffix of the directory name
>
> Or should I edit the makefiles and make buildroot (TI_GFX package more
> specifically) use my custom kernel's path while compiling PowerVR drivers?
>
> I guess this was discussed last month but I couldn't see how that discussion
> ended.
>
> Thanks again for the package,
> Sinan Akpolat

Sinan,

The best way to do this is to use the Kernel menu to configure a
source for your kernel (e.g. download a tarball, git tree, or patch on
top of a specific kernel version.) However, if the vendor does not
provide any of these methods, you can use the
LINUX_OVERRIDE_SRCDIR=<path/to/kernelsrc> which will override the
settings in the Kernel menu and use the local directory on your
machine.

FWIW: <PKG>_OVERRIDE_SRCDIR is a way to provide a source tree to
Buildroot for any package and is a useful variable for many other
packages.

The kernel menu will need to know the defconfig you are intending to
build and the load address (if version > 3.7).  If you need a custom
defconfig, the common solution is to create a directory in
board/<vendor>/<boardname>  with the kernel defconfig you would like
to use. This defconfig can then be referenced by the kernel menu by
setting BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG to y and
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE to
board/<vendor>/<boardname>/linux_defconfig.

A good reference on using Buildroot for custom projects is
http://free-electrons.com/~thomas/pub/using-buildroot-real-project.pdf
and the buildroot manual at
http://buildroot.uclibc.org/downloads/manual/manual.html .

Hope this information helps and thanks for reviewing this patch!

Thanks,
Spenser

--
Spenser Gilliland
Computer Engineer
Doctoral Candidate