kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP

[linux-2.6] / Documentation / kbuild / makefiles.txt

diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 1ca535bcc8c7d3adeae372d74bdea0fc801a9198..08fbe6cd309d7368cf529dc4a0b7299fd91e63be 100644 (file)
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -424,6 +424,7 @@ more details, with real examples.
        as-instr checks if the assembler reports a specific instruction
        and then outputs either option1 or option2
        C escapes are supported in the test instruction
+       Note: as-instr-option uses KBUILD_AFLAGS for $(AS) options
 
     cc-option
        cc-option is used to check if $(CC) supports a given option, and not
@@ -819,14 +820,14 @@ When kbuild executes, the following steps are followed (roughly):
        In this example, the binary $(obj)/image is a binary version of
        vmlinux. The usage of $(call if_changed,xxx) will be described later.
 
-    AFLAGS             $(AS) assembler flags
+    KBUILD_AFLAGS              $(AS) assembler flags
 
        Default value - see top level Makefile
        Append or modify as required per architecture.
 
        Example:
                #arch/sparc64/Makefile
-               AFLAGS += -m64 -mcpu=ultrasparc
+               KBUILD_AFLAGS += -m64 -mcpu=ultrasparc
 
     KBUILD_CFLAGS              $(CC) compiler flags
 
@@ -1098,7 +1099,7 @@ When kbuild executes, the following steps are followed (roughly):
        specified options when building the target vmlinux.lds.
 
        When building the *.lds target, kbuild uses the variables:
-       CPPFLAGS        : Set in top-level Makefile
+       KBUILD_CPPFLAGS : Set in top-level Makefile
        EXTRA_CPPFLAGS  : May be set in the kbuild makefile
        CPPFLAGS_$(@F)  : Target specific flags.
                          Note that the full filename is used in this