diff options
Diffstat (limited to 'Documentation')
-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 f099b814d383..6166e2d7da76 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt | |||
@@ -518,6 +518,28 @@ more details, with real examples. | |||
518 | In this example for a specific GCC version the build will error out explaining | 518 | In this example for a specific GCC version the build will error out explaining |
519 | to the user why it stops. | 519 | to the user why it stops. |
520 | 520 | ||
521 | cc-cross-prefix | ||
522 | cc-cross-prefix is used to check if there exist a $(CC) in path with | ||
523 | one of the listed prefixes. The first prefix where there exist a | ||
524 | prefix$(CC) in the PATH is returned - and if no prefix$(CC) is found | ||
525 | then nothing is returned. | ||
526 | Additional prefixes are separated by a single space in the | ||
527 | call of cc-cross-prefix. | ||
528 | This functionality is usefull for architecture Makefile that try | ||
529 | to set CROSS_COMPILE to well know values but may have several | ||
530 | values to select between. | ||
531 | It is recommended only to try to set CROSS_COMPILE is it is a cross | ||
532 | build (host arch is different from target arch). And is CROSS_COMPILE | ||
533 | is already set then leave it with the old value. | ||
534 | |||
535 | Example: | ||
536 | #arch/m68k/Makefile | ||
537 | ifneq ($(SUBARCH),$(ARCH)) | ||
538 | ifeq ($(CROSS_COMPILE),) | ||
539 | CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu-) | ||
540 | endif | ||
541 | endif | ||
542 | |||
521 | === 4 Host Program support | 543 | === 4 Host Program support |
522 | 544 | ||
523 | Kbuild supports building executables on the host for use during the | 545 | Kbuild supports building executables on the host for use during the |