linux

ARM: 8969/1: decompressor: simplify libfdt builds Copying source files during the build time may not end up with as clean code as expected. lib/fdt.c simply wrap scripts/dtc/libfdt/fdt.c, and it works nicely. Let's follow this approach for the arm decompressor, too. Add four wrappers, arch/arm/boot/compressed/fdt*.c and remove the Makefile messes. Another nice thing is we no longer need to maintain the own libfdt_env.h because the decompressor can include <linux/libfdt_env.h>. There is a subtle problem when generated files are turned into check-in files. When you are doing a rebuild of an existing object tree with O= option, there exists stale "shipped" copies that the old Makefile implementation created. The build system ends up with compiling the stale generated files because Make searches for prerequisites in the current directory, i.e. $(objtree) first, and then the directory listed in VPATH, i.e. $(srctree). To mend this issue, I added the following code: ifdef building_out_of_srctree $(shell rm -f $(addprefix $(obj)/, fdt_rw.c fdt_ro.c fdt_wip.c fdt.c)) endif This will need to stay for a while because "git bisect" crossing this commit, otherwise, would result in a build error. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> 2020-04-22 14:08:53 +01:00