i just want some confirmation that i'm on the right track for designing a
BSP layer to handle a particular combination of kernel versions and machines,
so all i'm after is mostly a, "yeah, that's how i'd do it," or a, "no,
that's idiotic."
the situation -- handle all possible combinations of:
* two kernel versions (say, 4.0 and 4.1)
* three machines:
* m1 (based on powerpc mpc8260)
* m2a, m2b (two closely related machines, based on mpc8360)
the additional wrinkle there is that, although there are three machines,
two of them are closely-related enough that there is the possibility that
.scc, .cfg or .patch files could apply in the following ways.
first, they could apply to a specific version of the kernel, or to any
version. no problem, that's easy.
regarding machines, those patches could possibly apply to:
* a single, specific machine
* all machines
* just to the mpc8360-based machines
so here's my idea.
in a linux.inc file, have the lines:
FILESEXTRAPATHS_prepend := "${THISDIR}/${BP}:${THISDIR}/${BPN}:"
MACHINEOVERRIDES_prepend_m2a = "mpc8360:"
MACHINEOVERRIDES_prepend_m2b = "mpc8360:"
that first line obviously extends my search path based on the kernel
version to look in (say, for kernel 4.0) in:
* linux-4.0/
* linux/
those next two lines deal with the fact that, for powerpc in this case,
with:
FILESOVERRIDES=${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}
TRANSLATED_TARGET_ARCH = "powerpc"
MACHINEOVERRIDES = "machine name"
so between the two of them, i want to sneak in "mpc8360" so that the search
order is specific machine, followed by the more general "mpc8360". sound good
so far?
next, for full flexibility, i can define three .bbappend files:
* linux_4.1.bbappend
* linux_4.0.bbappend
* linux_%.bbappend
since (as bruce mentioned recently), *all* matching bbappend files will
be processed in the (hopefully) intuitive order. (not sure i'll need that
wildcard .bbappend file, but i'll keep it in reserve, just in case.)
and, ***finally***, given all of the above, i'll have three directories
for SRC_URI items:
* linux-4.1/
* linux-4.0/
* linux/
where each directory will have the internal substructure:
* m1/
* m2a/
* m2b/
* mpc8360/
given all of the above, i think i've covered every conceivable possibility
for when patches might be applied. have i missed anything? is there an
easier way to do this?
rday
--
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