linux-yocto/Kbuild

SPDX-License-Identifier: GPL-2.0

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) check atomics headers are up-to-date

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

1) Generate bounds.h

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

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

$(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)

filechk_gentimeconst = echo $(CONFIG_HZ) | bc -q $<

$(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

arch/$(SRCARCH)/kernel/asm-offsets.s: $(timeconst-file) $(bounds-file)

$(offsets-file): arch/$(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) Check atomic headers are up-to-date

always += old-atomics targets += old-atomics

quiet_cmd_atomics = CALL $< cmd_atomics = $(CONFIG_SHELL) $<

old-atomics: scripts/atomic/check-atomics.sh FORCE $(call cmd,atomics)

6) Generate constants for Python GDB integration

extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py

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

Keep these three files during make clean

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