xref: /openbmc/linux/Kbuild (revision ba61bb17)
1# SPDX-License-Identifier: GPL-2.0
2#
3# Kbuild for top-level directory of the kernel
4# This file takes care of the following:
5# 1) Generate bounds.h
6# 2) Generate timeconst.h
7# 3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
8# 4) Check for missing system calls
9# 5) Generate constants.py (may need bounds.h)
10
11#####
12# 1) Generate bounds.h
13
14bounds-file := include/generated/bounds.h
15
16always  := $(bounds-file)
17targets := kernel/bounds.s
18
19# We use internal kbuild rules to avoid the "is up to date" message from make
20kernel/bounds.s: kernel/bounds.c FORCE
21	$(call if_changed_dep,cc_s_c)
22
23$(obj)/$(bounds-file): kernel/bounds.s FORCE
24	$(call filechk,offsets,__LINUX_BOUNDS_H__)
25
26#####
27# 2) Generate timeconst.h
28
29timeconst-file := include/generated/timeconst.h
30
31targets += $(timeconst-file)
32
33quiet_cmd_gentimeconst = GEN     $@
34define cmd_gentimeconst
35	(echo $(CONFIG_HZ) | bc -q $< ) > $@
36endef
37define filechk_gentimeconst
38	(echo $(CONFIG_HZ) | bc -q $< )
39endef
40
41$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE
42	$(call filechk,gentimeconst)
43
44#####
45# 3) Generate asm-offsets.h
46#
47
48offsets-file := include/generated/asm-offsets.h
49
50always  += $(offsets-file)
51targets += arch/$(SRCARCH)/kernel/asm-offsets.s
52
53# We use internal kbuild rules to avoid the "is up to date" message from make
54arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
55                                      $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
56	$(call if_changed_dep,cc_s_c)
57
58$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
59	$(call filechk,offsets,__ASM_OFFSETS_H__)
60
61#####
62# 4) Check for missing system calls
63#
64
65always += missing-syscalls
66targets += missing-syscalls
67
68quiet_cmd_syscalls = CALL    $<
69      cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
70
71missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
72	$(call cmd,syscalls)
73
74#####
75# 5) Generate constants for Python GDB integration
76#
77
78extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
79
80build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
81	@$(MAKE) $(build)=scripts/gdb/linux $@
82
83# Keep these three files during make clean
84no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)
85