The SRCREV_machine line does not work without having name=machine
attribute in SRC_URI.

This error is seen if the custom kernel recipe is used without
the name attribute:

NOTE: Error during finalise of .../linux-yocto-custom.bb
ERROR: ExpansionError during parsing .../linux-yocto-custom.bb: Failure expanding variable do_patch: ExpansionError: Failure expanding variable SRCPV, expression was ${@bb.fetch2.get_srcrev(d)} which triggered exception FetchError: Fetcher failure for URL: 'git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git;protocol=git;nocheckout=1'. Please set a valid SRCREV for url ['SRCREV_default_pn-linux-yocto-custom', 'SRCREV_default', 'SRCREV_pn-linux-yocto-custom', 'SRCREV'] (possible key names are git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git;protocol=git;nocheckout=1, or use a ;rev=X URL parameter)

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

The Yocto kernel tools look for SRCREV_machine in do_validate_branches,
if it's empty, it just returns and silently continues. This likely needs
at least a warning. However, this recipe should be using SRCREV_machine,
and not just SRCREV.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: Saul Wold <sgw@linux.intel.com>
Cc: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

It is necessary to supply file://defconfig to the SRC_URI when using
a defconfig (it is not implicitly understood as the commentary might
currently suggest).

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
CC: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

There has been some confusion over proper use of the linux-yocto-custom
recipe. It is not intended to build as is from meta-skeleton. It should
be modified via a bbappend file to provide a Linux kernel config at the
very least.

Update the commentary to make this requirement more explicit. Add some
additional detail about how to create a bbappend file and how and when
to modify the various variables.

Clear COMPATIBLE_MACHINE so bitbake will not attempt to build the recipe
unless the user explicitly adds there machine to the variable, which
should encourage them to read the recipe comments before attempting to
build it.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
CC: Bruce Ashfield <bruce.ashfield@windriver.com>
CC: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Remove the linux-tools include as perf is now packaged independently.
Without this, including meta-skeleton in bblayers.conf results in a
build failure as linux-tools.inc cannot be found.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>
CC: Tom Zanussi <tom.zanussi@intel.com>

Adding a skeleton/refrence recipe for using a subset of the yocto
kernel tools against kernel git repositories.

Sample/reference configuration fragments, features and a patch are
provided and documented in the recipe.

From the recipe itself:

   Provides an example/minimal kernel recipe that uses the linux-yocto
   and oe-core kernel classes to apply a subset of yocto kernel
   management to git managed kernel repositories.

 Notes:

   kconfig(s): the kernel must be configured with a defconfig, or via
               configuration fragment(s). Either of these can be added
               via bbappend.
   patches: patches can be merged into to the source git tree itself, added
            using standard bbappend syntax or controlled via .scc feature
            descriptions (also via bbappends)

   example configuration addition:
            SRC_URI += "file://smp.cfg"
   example patch addition (for kernel v3.4 only):
            SRC_URI += "file://0001-linux-version-tweak.patch
   example feature addition (for kernel v3.4 only):
            SRC_URI += "file://feature.scc"

 Warning:

   Building the sample kernel tree (kernel.org) without providing any
   configuration will result in build or boot errors. This is not a bug
   it is a required element for creating a valid kernel.

[YOCTO #2397]

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>