xref: /openbmc/linux/Kbuild (revision 8d325880)
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) check atomics headers are up-to-date
10# 6) Generate constants.py (may need bounds.h)
11
12#####
13# 1) Generate bounds.h
14
15bounds-file := include/generated/bounds.h
16
17always  := $(bounds-file)
18targets := kernel/bounds.s
19
20# We use internal kbuild rules to avoid the "is up to date" message from make
21kernel/bounds.s: kernel/bounds.c FORCE
22	$(call if_changed_dep,cc_s_c)
23
24$(obj)/$(bounds-file): kernel/bounds.s FORCE
25	$(call filechk,offsets,__LINUX_BOUNDS_H__)
26
27#####
28# 2) Generate timeconst.h
29
30timeconst-file := include/generated/timeconst.h
31
32targets += $(timeconst-file)
33
34quiet_cmd_gentimeconst = GEN     $@
35define cmd_gentimeconst
36	(echo $(CONFIG_HZ) | bc -q $< ) > $@
37endef
38define filechk_gentimeconst
39	(echo $(CONFIG_HZ) | bc -q $< )
40endef
41
42$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE
43	$(call filechk,gentimeconst)
44
45#####
46# 3) Generate asm-offsets.h
47#
48
49offsets-file := include/generated/asm-offsets.h
50
51always  += $(offsets-file)
52targets += arch/$(SRCARCH)/kernel/asm-offsets.s
53
54# We use internal kbuild rules to avoid the "is up to date" message from make
55arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
56                                      $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
57	$(call if_changed_dep,cc_s_c)
58
59$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
60	$(call filechk,offsets,__ASM_OFFSETS_H__)
61
62#####
63# 4) Check for missing system calls
64#
65
66always += missing-syscalls
67targets += missing-syscalls
68
69quiet_cmd_syscalls = CALL    $<
70      cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
71
72missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
73	$(call cmd,syscalls)
74
75#####
76# 5) Check atomic headers are up-to-date
77#
78
79always += old-atomics
80targets += old-atomics
81
82quiet_cmd_atomics = CALL    $<
83      cmd_atomics = $(CONFIG_SHELL) scripts/atomic/check-atomics.sh
84
85old-atomics: scripts/atomic/check-atomics.sh FORCE
86	$(call cmd,atomics)
87
88#####
89# 6) Generate constants for Python GDB integration
90#
91
92extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
93
94build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
95	@$(MAKE) $(build)=scripts/gdb/linux $@
96
97# Keep these three files during make clean
98no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)
99