Hi Zhangjin,
On Tue, Jul 25, 2023 at 10:30:06PM +0800, Zhangjin Wu wrote:
Hi, Willy
On Wed, Jul 19, 2023 at 05:14:07AM +0800, Zhangjin Wu wrote:
The default DEFCONFIG_<ARCH> may not always work for all architectures, some architectures require to add extra kernel config options, this adds a new 'extconfig' target for this requirement.
It allows to customize extra kernel config options via the common common.config and the architecture specific <ARCH>.config, at last trigger 'allnoconfig' to let them take effect with missing config options as disabled.
The scripts/kconfig/merge_config.sh tool is used to merge the extra config files.
Suggested-by: Thomas Wei?schuh linux@weissschuh.net Link: https://lore.kernel.org/lkml/67eb70d4-c9ff-4afc-bac7-7f36cc2c81bc@t-8ch.de/ Signed-off-by: Zhangjin Wu falcon@tinylab.org
tools/testing/selftests/nolibc/Makefile | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile index f42adef87e12..08a5ca5f418b 100644 --- a/tools/testing/selftests/nolibc/Makefile +++ b/tools/testing/selftests/nolibc/Makefile @@ -39,6 +39,9 @@ DEFCONFIG_s390 = defconfig DEFCONFIG_loongarch = defconfig DEFCONFIG = $(DEFCONFIG_$(ARCH)) +# extra kernel config files under configs/, include common + architecture specific +EXTCONFIG = common.config $(ARCH).config
# optional tests to run (default = all) TEST = @@ -162,6 +165,10 @@ initramfs: nolibc-test defconfig: $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare +extconfig:
- $(Q)$(srctree)/scripts/kconfig/merge_config.sh -O "$(srctree)" -m "$(srctree)/.config" $(foreach c,$(EXTCONFIG),$(wildcard $(CURDIR)/configs/$c))
- $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) KCONFIG_ALLCONFIG="$(srctree)/.config" allnoconfig
Please also mention this entry in the "help" message. Other than that, OK.
Willy, as we discussed in another tinyconfig series, in order to avoid add more complexity to users, I plan to drop this standalone 'extconfig' target and move the extra config operations to defconfig target like this:
defconfig: $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare $(Q)$(srctree)/scripts/kconfig/merge_config.sh -O "$(srctree)" -m "$(srctree)/.config" $(foreach c,$(EXTCONFIG),$(wildcard $(CURDIR)/configs/$c)) $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) KCONFIG_ALLCONFIG="$(srctree)/.config" allnoconfigThis extra config options are really critical to default boot and test, so, it should be a 'default' config action as the 'defconfig' target originally mean.
Will test carefully about this change, what's your idea?
Well, *iff* we need to have per-arch config settings, probably to better support Qemu, the console output, etc, then indeed we'd rather add them to all configs indeed. However the example above is bogus. First you create a default config, then prepare the rest of the kernel, then merge that config with the extensions (based on the arch and not the sub-arch BTW) then erase everything to restart from an allnoconfig.
Also if you're using merge_config you'll need -Q to disable warning about overridden options since you're starting from a defconfig which contains plenty of them. Usually I just do defconfig, append the few changes, then oldconfig and that's done. But merge_config can probably be fine as well. Also make prepare should be done last, to make sure that if it depends on anything in the config (e.g. 32 vs 64 bit etc) it's up to date.
Willy