On Thu, Sep 4, 2014 at 1:11 AM, Paul Bolle <pebolle@xxxxxxxxxx> wrote: > Hi Konstantin, > > On Mon, 2014-09-01 at 11:16 +0400, Konstantin Khlebnikov wrote: >> Cross-compiler tool prefix can be set in command line, in the environment >> variable CROSS_COMPILE or in config file, in option CONFIG_COROSS_COMPILE. >> Also some arch/*/Makefile provides default value. >> >> This patch links config option CONFIG_CROSS_COMPILE and variable CROSS_COMPILE >> in both directions: environment/command line has higher priority and updates >> value saved in the config file, config option acts as default value for it. >> >> This is especially useful together with option O=dir which allows to create >> separate directory for each target architecture and kernel flavor: >> >> # make O=build/arm ARCH=arm CROSS_COMPILE=arm-none-eabi- defconfig >> # make -C build/arm >> >> Signed-off-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx> > > I have only had a quick glance at this series. Just a quick question to > help me understand where it is going. > > Would this patch mean that, if a (def)config file has both ARCH and > CROSS_COMPILE set, one could use that (def)config file and invoke "make > $whatever_target" and expect it to do the right thing (provided a > suitable cross compiler is installed)? > > This implies cross compiler prefixes are standardized across > distributions, I guess. Maybe they're not. As I know they are not strictly standardized. Naming convention is arch[-vendor][-os]-abi, but there is a lot of possible combinations. > >> --- >> Makefile | 6 +++++- >> init/Kconfig | 1 + >> 2 files changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/Makefile b/Makefile >> index f648405..1044f40 100644 >> --- a/Makefile >> +++ b/Makefile >> @@ -263,7 +263,11 @@ endif >> # "make" in the configured kernel build directory always uses that. >> # Default value for CROSS_COMPILE is not to prefix executables >> # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile >> -CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%) >> +ifndef CROSS_COMPILE >> + CROSS_COMPILE := $(shell $(srctree)/scripts/config \ >> + --file $(KBUILD_OUTPUT)$(KCONFIG_CONFIG) \ >> + --if-undef "" --state "CROSS_COMPILE") >> +endif >> >> # Architecture as present in compile.h >> UTS_MACHINE := $(ARCH) >> diff --git a/init/Kconfig b/init/Kconfig >> index e84c642..1c2f621 100644 >> --- a/init/Kconfig >> +++ b/init/Kconfig >> @@ -47,6 +47,7 @@ config INIT_ENV_ARG_LIMIT >> >> config CROSS_COMPILE >> string "Cross-compiler tool prefix" >> + option env="CROSS_COMPILE" >> help >> Same as running 'make CROSS_COMPILE=prefix-' but stored for >> default make runs in this kernel build directory. You don't >> > > > Paul Bolle > -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
