[PATCH 0/3] arm64: configs: Provide slimmed down configuration for guests

[Mark Brown]

It has been noted that due to the extensive platform support it
enables the arm64 defconfig is rather large and takes a while to
build in comparison with other architectures which can be a
burden when doing cross architecture work, especially when
testing is mainly in emulation.  We can mitigate this by providing
a configuration that only enables the support required to run in
mach-virt, this will be much smaller and quicker to build.

Having two completely separate configurations would mean that we'd
need to make any changes to the architecture wide configuration in
both the existing defconfig and the new configuration if we wanted to
ensure consistent default behaviour.  Instead define a new config
fragement which turns off options from defconfig which enable platform
support, currently this just covers the ARCH_ options that control SoC
specific drivers as validation for this approach - if people are happy
with this approach we can build on it to further reduce the size of the
new configuration.

The resulting configuration builds about 25% faster for me.

v2:
 - Rework to base on turning off options from defconfig rather than 
   splitting out a base configuration and then adding things to it.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
Mark Brown (3):
      scripts: merge_config: Add option to suppress warning on overrides
      kbuild: Provide a version of merge_into_defconfig without override warnings
      arm64: configs: Add virtconfig

 arch/arm64/Makefile             |  6 ++++++
 arch/arm64/configs/virt.config  | 39 +++++++++++++++++++++++++++++++++++++++
 scripts/Makefile.defconf        | 14 ++++++++++++++
 scripts/kconfig/merge_config.sh | 25 ++++++++++++++++---------
 4 files changed, 75 insertions(+), 9 deletions(-)
---
base-commit: 4fafd96910add124586b549ad005dcd179de8a18
change-id: 20230203-arm64-defconfigs-c04cf5fa6288

Best regards,
-- 
Mark Brown <broonie at kernel.org>