When configuring the kernel using one of the generic MIPS defconfig
targets, the generic-board-config.sh script is used to check
requirements listed in board config fragments against a reference config
in order to determine which board config fragments to merge into the
final config.
When specifying O= to configure in a directory other than the kernel
source directory, this generic-board-config.sh script is invoked in the
directory that we are configuring in (ie. the directory that O equals),
and the path to the reference config is relative to the current
directory. The script then changes the current directory to the source
tree, which unfortunately breaks later access to the reference file
since its path is relative to a directory that is no longer the current
working directory. This results in configuration failing with errors
such as:
$ make ARCH=mips O=tmp 32r2_defconfig
make[1]: Entering directory '/home/pburton/src/linux/tmp'
Using ../arch/mips/configs/generic_defconfig as base
Merging ../arch/mips/configs/generic/32r2.config
Merging ../arch/mips/configs/generic/eb.config
grep: ./.config.32r2_defconfig: No such file or directory
grep: ./.config.32r2_defconfig: No such file or directory
The base file '.config' does not exist. Exit.
make[1]: *** [arch/mips/Makefile:505: 32r2_defconfig] Error 1
make[1]: Leaving directory '/home/pburton/src/linux-ingenic/tmp'
make: *** [Makefile:145: sub-make] Error 2
Fix this by avoiding changing the working directory in
generic-board-config.sh, instead using full paths to files under
$(srctree)/ where necessary.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 27e0d4b051 ("MIPS: generic: Allow filtering enabled boards by requirements")
Cc: linux-mips@linux-mips.org
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: kbuild-all@01.org
Patchwork: https://patchwork.linux-mips.org/patch/17231/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Up until now when configuring a generic kernel all board config
fragments have been merged by default unless boards are explicitly
selected by the user specifying BOARDS=.
In many cases this is sub-optimal, since some boards don't make sense to
include in some kernels. For example the MIPS SEAD-3 development board
has only ever been used with 32 bit CPUs, so including support for the
SEAD-3 in a 64 bit kernel is wasteful.
This patch introduces support for specifying requirements in board
config fragments, using comments formatted like so:
# require CONFIG_BLA=y
For example the SEAD-3 board could specify that it should only be merged
for 32 bit kernels using a requirement line like the following:
# require CONFIG_32BIT=y
A new generic-board-config.sh script is introduced to handle selecting
the board config fragments to merge & calling merge_config.sh to merge
them. In order to allow requirements to check Kconfig symbols that are
implicitly selected, rather than explicitly specified by
generic_defconfig or one of the ISA config fragments, an intermediate
.config file is saved & used as a reference when checking requirements.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16943/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton