[OE-core] [PATCH 4/8] kernel: Pull uImage generation into separate class

[Marek Vasut]

On Tuesday, April 28, 2015 at 08:44:54 PM, Bruce Ashfield wrote:
> On 2015-04-28 12:38 PM, Marek Vasut wrote:
> > Pull the uImage image format generation from kernel.bbclass into
> > a separate kernel-uimage.bbclass. The recipes which now need to
> > generate an uImage will have to inherit kernel-uimage instead of
> > kernel class.
> > 
> > Signed-off-by: Marek Vasut <marex at denx.de>
> > Cc: Richard Purdie <richard.purdie at linuxfoundation.org>
> > Cc: Koen Kooi <koen at dominion.thruhere.net>
> > Cc: Paul Eggleton <paul.eggleton at linux.intel.com>
> > Cc: Ross Burton <ross.burton at intel.com>
> > Cc: Bruce Ashfield <bruce.ashfield at windriver.com>
> > ---
> > 
> >   meta/classes/kernel-uimage.bbclass | 48
> >   +++++++++++++++++++++++++++++++++ meta/classes/kernel.bbclass        |
> >   55 +++++++------------------------------- 2 files changed, 58
> >   insertions(+), 45 deletions(-)
> >   create mode 100644 meta/classes/kernel-uimage.bbclass
> > 
> > NOTE: The "inherit kernel-uimage" in kernel.bbclass should be changed to
> > 
> >        something like "inherit kernel-${@d.getVar("KERNEL_IMAGETYPE",
> >        True).lower()}" but the problem is that I only want to perform
> >        the inheritance for uimage and fitimage, the other image types
> >        don't need to inherit any additional special stuff.
> >        Paul suggested I can do "inherit <empty here>". This would at
> >        least let me implement a python function which returns either
> >        "kernel-uimage", "kernel-fitimage" or "" and based on that, I
> >        could inherit the particular image type specifics into
> >        kernel.bbclass.
> >        What I don't know how to implement well is this function which
> >        returns those three strings based on the KERNEL_IMAGETYPE. What I
> >        would like to avoid is encoding those strings explicitly into the
> >        function, since that would force each new kernel image format to
> >        also edit this function in kernel.bbclass . Apparently, checking
> >        whether class exists and inheriting it only if it does is also
> >        not a simple task.
> 
> Agreed that this would be better. It would remove a lot of the checks
> in the other tasks for the image type.

Hi!

Yes, that's indeed true. All the image type checks would disappear from
kernel-uimage and kernel-fitimage bbclasses.

> I'm not aware of the exact details on how to make this work, but
> hopefully others have the foo.

Thank you!