The assembler files in the kernel are *.S instead of *.s, so they must
be preprocessed. Since 'as' of GNU binutils is not able to preprocess,
we always use $(CC) as an assembler driver.
$(AS) is almost unused in Kbuild. As of writing, there is just one place
that directly invokes $(AS).
$ git grep -e '$(AS)' -e '${AS}' -e '$AS' -e '$(AS:' -e '${AS:' -- :^Documentation
drivers/net/wan/Makefile: AS68K = $(AS)
The documentation about *_AFLAGS* sounds like the flags were passed
to $(AS). This is somewhat misleading.
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---
Changes in v2:
- Rephrase without using "assembling"
Documentation/kbuild/kbuild.txt | 5 ++---
Documentation/kbuild/makefiles.txt | 12 ++++++------
2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt
index 9c230ea71963..2c6188abb213 100644
--- a/Documentation/kbuild/kbuild.txt
+++ b/Documentation/kbuild/kbuild.txt
@@ -31,12 +31,11 @@ Additional options to the assembler (for built-in and modules).
AFLAGS_MODULE
--------------------------------------------------
-Additional module specific options to use for $(AS).
+Additional assembler options for modules.
AFLAGS_KERNEL
--------------------------------------------------
-Additional options for $(AS) when used for assembler
-code for code that is compiled as built-in.
+Additional assembler options for built-in.
KCFLAGS
--------------------------------------------------
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index d65ad5746f94..895bbbf38a0c 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -306,7 +306,7 @@ more details, with real examples.
variable $(KBUILD_CFLAGS) and uses it for compilation flags for the
entire tree.
- asflags-y specifies options for assembling with $(AS).
+ asflags-y specifies assembler options.
Example:
#arch/sparc/kernel/Makefile
@@ -441,7 +441,7 @@ 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
+ Note: as-instr-option uses KBUILD_AFLAGS for assembler options
cc-option
cc-option is used to check if $(CC) supports a given option, and if
@@ -814,7 +814,7 @@ 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.
- KBUILD_AFLAGS $(AS) assembler flags
+ KBUILD_AFLAGS assembler flags
Default value - see top level Makefile
Append or modify as required per architecture.
@@ -853,15 +853,15 @@ When kbuild executes, the following steps are followed (roughly):
The first example utilises the trick that a config option expands
to 'y' when selected.
- KBUILD_AFLAGS_KERNEL $(AS) options specific for built-in
+ KBUILD_AFLAGS_KERNEL Assembler options specific for built-in
$(KBUILD_AFLAGS_KERNEL) contains extra C compiler flags used to compile
resident kernel code.
- KBUILD_AFLAGS_MODULE Options for $(AS) when building modules
+ KBUILD_AFLAGS_MODULE Assembler options specific for modules
$(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that
- are used for $(AS).
+ are used for assembler.
From commandline AFLAGS_MODULE shall be used (see kbuild.txt).
KBUILD_CFLAGS_KERNEL $(CC) options specific for built-in
--
2.17.1
