Support incremental builds in Hostboot
Previously, on every build, the makefile for the Hostboot package was
updating the timestamp of a Hostboot source file on which nearly all
other Hostboot files have a dependency. This causes files that
haven't changed to be rebuilt, which takes a lot of time.
This commit changes the makefile to only update the relevant file if
it needs to do so. This speeds up Hostboot rebuilds by a large factor.
diff --git a/openpower/package/hostboot-p10/hostboot-p10.mk b/openpower/package/hostboot-p10/hostboot-p10.mk
index 9a766a2..f5c1d31 100644
--- a/openpower/package/hostboot-p10/hostboot-p10.mk
+++ b/openpower/package/hostboot-p10/hostboot-p10.mk
@@ -29,7 +29,11 @@
# to be created for src/include/usr/tracinterface.H; so delete it and rebuild it
# manually
define HOSTBOOT_P10_BUILD_CMDS
- $(HOSTBOOT_P10_ENV_VARS) bash -c 'cd $(@D) && rm -f src/include/usr/tracinterface.H && cp src/include/usr/trace/interface.H src/include/usr/tracinterface.H && source ./env.bash && $(MAKE)'
+ $(HOSTBOOT_P10_ENV_VARS) bash -c 'cd $(@D) \
+ && if ! cmp --quiet src/include/usr/trace/interface.H src/include/usr/tracinterface.H ; then \
+ rm -f src/include/usr/tracinterface.H && cp src/include/usr/trace/interface.H src/include/usr/tracinterface.H ; \
+ fi \
+ && source ./env.bash && $(MAKE)'
endef
define HOSTBOOT_P10_INSTALL_IMAGES_CMDS