linux-yocto/Kbuild
Nicholas Mc Guire 0a227985d4 time: Move timeconst.h into include/generated
kernel/time/timeconst.h is moved to include/generated/ and generated 
by the top level Kbuild. This allows using timeconst.h in an earlier
build stage.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Joe Perches <joe@perches.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Paul Turner <pjt@google.com>
Cc: Michal Marek <mmarek@suse.cz>
Link: http://lkml.kernel.org/r/1431951554-5563-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 15:13:45 +02:00

2.6 KiB

Kbuild for top-level directory of the kernel

This file takes care of the following:

1) Generate bounds.h

2) Generate timeconst.h

3) Generate asm-offsets.h (may need bounds.h and timeconst.h)

4) Check for missing system calls

Default sed regexp - multiline due to syntax constraints

define sed-y "/^->/{s:->#.*:/* \1 /:;
s:^->[^ ]* [$$#]
[-0-9]* .*:#define \1 \2 /* \3 /:;
s:^->[^ ]* [$$#]
[^ ]* .*:#define \1 \2 /* \3 */:;
s:->::; p;}" endef

Use filechk to avoid rebuilds when a header changes, but the resulting file

does not

define filechk_offsets (set -e;
echo "#ifndef $2";
echo "#define $2";
echo "/*";
echo " * DO NOT MODIFY.";
echo " *";
echo " * This file was generated by Kbuild";
echo " */";
echo "";
sed -ne $(sed-y);
echo "";
echo "#endif" ) endef

1) Generate bounds.h

bounds-file := include/generated/bounds.h

always := $(bounds-file) targets := kernel/bounds.s

We use internal kbuild rules to avoid the "is up to date" message from make

kernel/bounds.s: kernel/bounds.c FORCE $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c)

$(obj)/$(bounds-file): kernel/bounds.s FORCE $(call filechk,offsets,LINUX_BOUNDS_H)

2) Generate timeconst.h

timeconst-file := include/generated/timeconst.h

#always += $(timeconst-file) targets += $(timeconst-file)

quiet_cmd_gentimeconst = GEN $@ define cmd_gentimeconst (echo $(CONFIG_HZ) | bc -q $< ) > $@ endef define filechk_gentimeconst (echo $(CONFIG_HZ) | bc -q $< ) endef

$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE $(call filechk,gentimeconst)

3) Generate asm-offsets.h

offsets-file := include/generated/asm-offsets.h

always += $(offsets-file) targets += arch/$(SRCARCH)/kernel/asm-offsets.s

We use internal kbuild rules to avoid the "is up to date" message from make

arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c
$(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c)

$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE $(call filechk,offsets,ASM_OFFSETS_H)

4) Check for missing system calls

always += missing-syscalls targets += missing-syscalls

quiet_cmd_syscalls = CALL $< cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)

missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE $(call cmd,syscalls)

Keep these three files during make clean

no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)