kbuild: save ARCH & CROSS_COMPILE when building a kernel
When building a kernel for a different architecture
kbuild requires the user always to specify ARCH and
CROSS_COMPILE on the command-line.
We use the asm symlink to detect if user forgets to
specify the correct ARCH value - but that symlink
is about to die. And we do now want to loose this check.
This patch save the settings of ARCH and CROSS_COMPILE
in two files named:
include/generated/kernel.arch
include/generated/kernel.cross
The settings are saved during "make *config" time
and always read.
If user try to change the settings we error out.
This works both for plain builds and for O=...
builds.
So now you can do:
$ mkdir sparc64
$ make O=sparc64 ARCH=sparc64 CROSS_COMPILE=sparc64-linux- defconfig
$ cd sparc64
$ make
Notice that you no longer need to tell kbuild
the settings of ARCH and CROSS_COMPILE when you type make
in the output directory.
Likewise for plain builds where you do not use O=...
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Roland McGrath <roland@redhat.com>
1 file changed