Hello Masahiro Yamada,
Even the with this patch, we encountered a false error of generic board support. The problem was very interrmittent for us, but we were able to debug the problem to performing builds on EXT3 file systems which have a time stamp resolution of one second. To reproduce the problem, touch ./include/config/auto.conf and .config on a configured uboot tree on an EXT3 file system.
The patch below fixes the problem for us.
Thanks,
Matthew Gerlach
--- Makefile | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile index 99097e1..84de2f9 100644 --- a/Makefile +++ b/Makefile @@ -493,8 +493,12 @@ include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd # is up-to-date. When we switch to a different board configuration, old CONFIG # macros are still remaining in include/config/auto.conf. Without the following # gimmick, wrong config.mk would be included leading nasty warnings/errors. -autoconf_is_current := $(if $(wildcard $(KCONFIG_CONFIG)),$(shell find . \ - -path ./include/config/auto.conf -newer $(KCONFIG_CONFIG))) +# We use if not (not -newer) so that we include config.mk in the event that the +# file timestamps are exacty equal which can happen on EXT3 filesystems. +autoconf_is_current := $(if $(wildcard $(KCONFIG_CONFIG)),\ + $(if $(shell find . -path ./include/config/auto.conf \ + ! -newer $(KCONFIG_CONFIG)),,./include/config/auto.conf)) + ifneq ($(autoconf_is_current),) include $(srctree)/config.mk endif