linux-yocto/Kbuild
Matthias Kaehlcke ebf003f0cf kbuild: Consolidate header generation from ASM offset information
Largely redundant code is used in different places to generate C headers
from offset information extracted from assembly language output.
Consolidate the code in Makefile.lib and use this instead.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-04-13 05:43:37 +09:00

2.2 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

5) Generate constants.py (may need bounds.h)

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

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)

5) Generate constants for Python GDB integration

extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py

build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file) @$(MAKE) $(build)=scripts/gdb/linux $@

Keep these three files during make clean

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