[PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

From: Peter Foley
Date: Tue Jul 05 2011 - 19:44:31 EST


When IKCONFIG is built-in make oldconfig will cause the kernel to be
relinked even if .config didn't change. This happens because of a
config_data.gz dependency on .config. This patch changes the if_changed to
a filechk so that config_data.h is only rebuilt when the contents
have actually changed.

Signed-off-by: Peter Foley <pefoley2@xxxxxxxxxxx>
---
kernel/Makefile | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 2d64cfc..d06467f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -125,11 +125,10 @@ targets += config_data.gz
$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(call if_changed,gzip)

-quiet_cmd_ikconfiggz = IKCFG $@
- cmd_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@
+ filechk_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;")
targets += config_data.h
$(obj)/config_data.h: $(obj)/config_data.gz FORCE
- $(call if_changed,ikconfiggz)
+ $(call filechk,ikconfiggz)

$(obj)/time.o: $(obj)/timeconst.h

--
1.7.5.3

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