Documentation: update kbuild make typos/grammar/text flow

Update section 3.7 examples to reflect the current state of the
Makefiles used. Fix spelling and grammar errors along with flow of text.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matt Mooney 2010-08-05 11:23:11 -07:00 committed by Linus Torvalds
parent 2f5a2f8184
commit eb07e1b4ac

View File

@ -285,45 +285,42 @@ more details, with real examples.
--- 3.7 Compilation flags --- 3.7 Compilation flags
ccflags-y, asflags-y and ldflags-y ccflags-y, asflags-y and ldflags-y
The three flags listed above applies only to the kbuild makefile The three flags listed above apply only to the kbuild makefile where
where they are assigned. They are used for all the normal they are assigned (i.e., per-directory). They are used for all the
cc, as and ld invocation happenign during a recursive build. normal cc, as and ld invocation happening during a recursive build.
Note: Flags with the same behaviour were previously named: Note: Flags with the same behaviour were previously named:
EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS. EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS. They are still
They are yet supported but their use are deprecated. supported but their use is deprecated.
ccflags-y specifies options for compiling C files with $(CC). ccflags-y specifies options for compiling with $(CC).
Example: Example:
# drivers/sound/emu10k1/Makefile # drivers/acpi/Makefile
ccflags-y += -I$(obj) ccflags-y := -Os
ccflags-$(DEBUG) += -DEMU10K1_DEBUG ccflags-$(CONFIG_ACPI_DEBUG) += -DACPI_DEBUG_OUTPUT
This variable is necessary because the top Makefile owns the This variable is necessary because the top Makefile owns the
variable $(KBUILD_CFLAGS) and uses it for compilation flags for the variable $(KBUILD_CFLAGS) and uses it for compilation flags for the
entire tree. entire tree.
asflags-y is a similar string for per-directory options asflags-y specifies options for assembling with $(AS).
when compiling assembly language source.
Example: Example:
#arch/x86_64/kernel/Makefile #arch/sparc/kernel/Makefile
asflags-y := -traditional asflags-y := -ansi
ldflags-y specifies options for linking with $(LD).
ldflags-y is a string for per-directory options to $(LD).
Example: Example:
#arch/m68k/fpsp040/Makefile #arch/cris/boot/compressed/Makefile
ldflags-y := -x ldflags-y += -T $(srctree)/$(src)/decompress_$(arch-y).lds
subdir-ccflags-y, subdir-asflags-y subdir-ccflags-y, subdir-asflags-y
The two flags listed above are similar to ccflags-y and as-falgs-y. The two flags listed above are similar to ccflags-y and asflags-y.
The difference is that the subdir- variants has effect for the kbuild The difference is that the subdir- variants affect the kbuild
file where tey are present and all subdirectories. file where they are present and all subdirectories. Options specified
Options specified using subdir-* are added to the commandline before using subdir-* are added to the commandline before the options
the options specified using the non-subdir variants. specified using the non-subdir variants.
Example: Example:
subdir-ccflags-y := -Werror subdir-ccflags-y := -Werror
@ -341,18 +338,18 @@ more details, with real examples.
CFLAGS_aha152x.o = -DAHA152X_STAT -DAUTOCONF CFLAGS_aha152x.o = -DAHA152X_STAT -DAUTOCONF
CFLAGS_gdth.o = # -DDEBUG_GDTH=2 -D__SERIAL__ -D__COM2__ \ CFLAGS_gdth.o = # -DDEBUG_GDTH=2 -D__SERIAL__ -D__COM2__ \
-DGDTH_STATISTICS -DGDTH_STATISTICS
CFLAGS_seagate.o = -DARBITRATE -DPARITY -DSEAGATE_USE_ASM
These three lines specify compilation flags for aha152x.o, These two lines specify compilation flags for aha152x.o and gdth.o.
gdth.o, and seagate.o
$(AFLAGS_$@) is a similar feature for source files in assembly $(AFLAGS_$@) is a similar feature for source files in assembly
languages. languages.
Example: Example:
# arch/arm/kernel/Makefile # arch/arm/kernel/Makefile
AFLAGS_head-armv.o := -DTEXTADDR=$(TEXTADDR) -traditional AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
AFLAGS_head-armo.o := -DTEXTADDR=$(TEXTADDR) -traditional AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt
--- 3.9 Dependency tracking --- 3.9 Dependency tracking