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authorSam Ravnborg <sam@ravnborg.org>2010-07-28 17:33:09 +0200
committerMichal Marek <mmarek@suse.cz>2010-08-03 14:09:45 +0200
commit6588169d516560f68672e2928680b71c647b7806 (patch)
tree91b20bf9197c718ff4b5830bb1aea0b1bc0de272 /Documentation/kbuild
parentd6f4ceb796ebf1a8c8a9ad4a8ea0d181aaec7de6 (diff)
downloadlwn-6588169d516560f68672e2928680b71c647b7806.tar.gz
lwn-6588169d516560f68672e2928680b71c647b7806.zip
kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command line
It is now possible to assign options to AS, CC and LD on the command line - which is only used when building modules. {A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC, LD when building modules without overriding the original value. Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE that is used by arch specific files and free up {A,C,LD}FLAGS_MODULE so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Note: Previously we had a MODFLAGS variable for both AS and CC. But in favour of consistency this was dropped. So in some cases arch Makefile has one assignmnet replaced by two assignmnets. Note2: MODFLAGS was not documented and is dropped without any notice. I do not expect much/any breakage from this. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32] Signed-off-by: Michal Marek <mmarek@suse.cz>
Diffstat (limited to 'Documentation/kbuild')
-rw-r--r--Documentation/kbuild/kbuild.txt16
-rw-r--r--Documentation/kbuild/makefiles.txt18
2 files changed, 29 insertions, 5 deletions
diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt
index 634c625da8ce..d9c655433ec6 100644
--- a/Documentation/kbuild/kbuild.txt
+++ b/Documentation/kbuild/kbuild.txt
@@ -22,11 +22,23 @@ building C files and assembler files.
KAFLAGS
--------------------------------------------------
-Additional options to the assembler.
+Additional options to the assembler (for built-in and modules).
+
+AFLAGS_MODULE
+--------------------------------------------------
+Addtional module specific options to use for $(AS).
KCFLAGS
--------------------------------------------------
-Additional options to the C compiler.
+Additional options to the C compiler (for built-in and modules).
+
+CFLAGS_MODULE
+--------------------------------------------------
+Addtional module specific options to use for $(CC).
+
+LDFLAGS_MODULE
+--------------------------------------------------
+Additional options used for $(LD) when linking modules.
KBUILD_VERBOSE
--------------------------------------------------
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 71c602d61680..802341abf702 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -928,11 +928,23 @@ When kbuild executes, the following steps are followed (roughly):
$(CFLAGS_KERNEL) contains extra C compiler flags used to compile
resident kernel code.
- CFLAGS_MODULE $(CC) options specific for modules
+ KBUILD_AFLAGS_MODULE Options for $(AS) when building modules
- $(CFLAGS_MODULE) contains extra C compiler flags used to compile code
- for loadable kernel modules.
+ $(KBUILD_AFLAGS_MODULE) is used to add arch specific options that
+ are used for $(AS).
+ From commandline AFLAGS_MODULE shall be used (see kbuild.txt).
+ KBUILD_CFLAGS_MODULE Options for $(CC) when building modules
+
+ $(KBUILD_CFLAGS_MODULE) is used to add arch specific options that
+ are used for $(CC).
+ From commandline CFLAGS_MODULE shall be used (see kbuild.txt).
+
+ KBUILD_LDFLAGS_MODULE Options for $(LD) when linking modules
+
+ $(KBUILD_LDFLAGS_MODULE) is used to add arch specific options
+ used when linking modules. This is often a linker script.
+ From commandline LDFLAGS_MODULE shall be used (see kbuild.txt).
--- 6.2 Add prerequisites to archprepare: