Our build system still parses ad-hoc CONFIG options in header files
and generates include/autoconf.mk so that Makefiles can reference
them. This gimmick was introduced in the pre-Kconfig days and will
be kept until Kconfig migration is completed.
The include/autoconf.mk is generated like follows:
[1] Preprocess include/common.h with -DDO_DEPS_ONLY and
retrieve macros into include/autoconf.mk.tmp
[2] Reformat include/autoconf.mk.dep into include/autoconf.mk
with tools/scripts/define2mk.sed script
[3] Remove include/autoconf.mk.tmp
Here, include/autoconf.mk.tmp is similar to u-boot.cfg, which is
also generated by preprocessing include/config.h with -DDO_DEPS_ONLY.
In other words, there is much overlap among include/autoconf.mk and
u-boot.cfg build rules.
So, the idea is to split the build rule of include/autoconf.mk
into two stages. The first preprocesses headers into u-boot.cfg.
The second parses the u-boot.cfg into include/autoconf.mk. The
build rules of u-boot.cfg in Makefile and spl/Makefile will be gone.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
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