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Diffstat (limited to 'Documentation/kbuild/makefiles.txt')
| -rw-r--r-- | Documentation/kbuild/makefiles.txt | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index f099b814d38..7a7753321a2 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -518,6 +518,28 @@ more details, with real examples. In this example for a specific GCC version the build will error out explaining to the user why it stops. + cc-cross-prefix + cc-cross-prefix is used to check if there exists a $(CC) in path with + one of the listed prefixes. The first prefix where there exist a + prefix$(CC) in the PATH is returned - and if no prefix$(CC) is found + then nothing is returned. + Additional prefixes are separated by a single space in the + call of cc-cross-prefix. + This functionality is useful for architecture Makefiles that try + to set CROSS_COMPILE to well-known values but may have several + values to select between. + It is recommended only to try to set CROSS_COMPILE if it is a cross + build (host arch is different from target arch). And if CROSS_COMPILE + is already set then leave it with the old value. + + Example: + #arch/m68k/Makefile + ifneq ($(SUBARCH),$(ARCH)) + ifeq ($(CROSS_COMPILE),) + CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu-) + endif + endif + === 4 Host Program support Kbuild supports building executables on the host for use during the |