# Invoke a second make in the output directory, passing relevant variables
# check that the output directory actually exists
saved-output := $(KBUILD_OUTPUT)
-KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)
+KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
+ && /bin/pwd)
$(if $(KBUILD_OUTPUT),, \
$(error output directory "$(saved-output)" does not exist))
clean: rm-dirs := $(CLEAN_DIRS)
clean: rm-files := $(CLEAN_FILES)
-clean-dirs := $(foreach f,$(u-boot-alldirs),$(if $(wildcard $f/Makefile),$f))
+clean-dirs := $(foreach f,$(u-boot-alldirs),$(if $(wildcard $(srctree)/$f/Makefile),$f))
clean-dirs := $(addprefix _clean_, $(clean-dirs) doc/DocBook)