On Tuesday 12 May 2015 21:27:30 Marek Vasut wrote:
> On Tuesday, May 12, 2015 at 06:18:15 PM, Paul Eggleton wrote:
> > On Tuesday 12 May 2015 11:38:14 Bruce Ashfield wrote:
> > > On 2015-05-12 10:15 AM, Paul Eggleton wrote:
> > > > On Monday 04 May 2015 23:41:47 Marek Vasut wrote:
> > > >> On Tuesday, April 28, 2015 at 11:16:17 PM, Marek Vasut wrote:
> > > >>> 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.
> > > >>
> > > >> Any ideas please ?
> > > >
> > > > To me this is about how we wish to structure these classes. That's not
> > > > my call, but to enumerate the options - unless I'm missing something
> > > > we have to choose between:
> > > >
> > > > 1) Hardcode uimage/fitimage. Hard to extend.
> > > >
> > > > 2) inherit kernel-<type> and just insist that a class for every image
> > > > type exists. Ugly and kernel-*.bbclass already exists.
> > > >
> > > > 3) Try to search for a kernel-<type> class and inherit it if one is
> > > > found. AFAIK we don't do this kind of thing anywhere else so this
> > > > doesn't seem right to me.
> > > >
> > > > 4) Establish some other mechanism for registering kernel image type
> > > > classes
> > > > (KERNEL_CLASSES ?). Not sure if we want to do this but it is at least
> > > > a
> > > > common mechanism elsewhere in the system.
> > >
> > > I wasn't familiar with an option like this, but if we can do something
> > > for the kernel classes that follows the existing patterns .. it makes
> > > a lot of sense. I really don't want to invent something new here either.
> > >
> > > So something along the lines of the way that image.bbclass works with
> > > the IMAGE_CLASSES ?
> >
> > Indeed, that's what I was referring to.
>
> Doesn't that mean it would be possible for kernel.bbclass to inherit
> multiple classes -- for example kernel-uimage.bbclass and
> kernel-fitimage.bbclass -- at the same time ? Won't that make it impossible
> to remove the kernel type checks in kernel-uimage.bbclass ? But maybe
> having those checks in place is the right thing to do since there might be
> a target building both fitImage and uImage at the same time?
You will still need these checks, yes. To be honest I don't consider having
those to be a bad thing though.
Cheers,
Paul
--
Paul Eggleton
Intel Open Source Technology Centre