On Mon, Apr 12, 2021 at 4:44 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > > Hi Yamada-san, > > On Sun, Apr 11, 2021 at 3:56 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > Use ?= operator to let arch/*/Makefile to assign CROSS_COMPILE only > > when CROSS_COMPILE is undefined. > > > > This allows arch-Makefiles to drop the ifeq ($(CROSS_COMPILE),) > > conditional. > > > > This slightly changes the behavior; the arch-Makefile previously > > overrode CROSS_COMPILE when CROSS_COMPILE has already been made empty > > via an environment variable as in 'export CROSS_COMPILE='. > > > > With this commit, arch-Makefle will respect the user's environment > > set-up, which seems to be a more correct behavior. > > > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > > Thanks for your patch! > > > --- > > > > arch/arc/Makefile | 4 +--- > > arch/h8300/Makefile | 4 +--- > > arch/m68k/Makefile | 4 +--- > > arch/mips/Makefile | 4 +--- > > arch/parisc/Makefile | 6 ++---- > > arch/sh/Makefile | 4 +--- > > What about arch/xtensa/Makefile? > > > --- a/arch/m68k/Makefile > > +++ b/arch/m68k/Makefile > > @@ -17,10 +17,8 @@ > > KBUILD_DEFCONFIG := multi_defconfig > > > > ifneq ($(SUBARCH),$(ARCH)) > > - ifeq ($(CROSS_COMPILE),) > > - CROSS_COMPILE := $(call cc-cross-prefix, \ > > + CROSS_COMPILE ?= $(call cc-cross-prefix, \ > > m68k-linux-gnu- m68k-linux- m68k-unknown-linux-gnu-) > > - endif > > endif > > This does not seem to work as expected: my standard build scripts > (using "make ARCH=m68k") no longer pick up the cross-compiler, > but fall back to the native compiler, thus breaking the build. Agh, sorry, this patch does not work because the top Makefile exports CROSS_COMPILE. export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC Removing CROSS_COMPILE from that makes ?= work, but it would break other parts. Please ignore this patch. > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds -- Best Regards Masahiro Yamada