xref: /linux/Kbuild (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
1#
2# Kbuild for top-level directory of the kernel
3# This file takes care of the following:
4# 1) Generate bounds.h
5# 2) Generate timeconst.h
6# 3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
7# 4) Check for missing system calls
8# 5) Generate constants.py (may need bounds.h)
9
10#####
11# 1) Generate bounds.h
12
13bounds-file := include/generated/bounds.h
14
15always  := $(bounds-file)
16targets := kernel/bounds.s
17
18# We use internal kbuild rules to avoid the "is up to date" message from make
19kernel/bounds.s: kernel/bounds.c FORCE
20	$(Q)mkdir -p $(dir $@)
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	$(Q)mkdir -p $(dir $@)
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	$(call cmd,syscalls)
74
75#####
76# 5) Generate constants for Python GDB integration
77#
78
79extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
80
81build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
82	@$(MAKE) $(build)=scripts/gdb/linux $@
83
84# Keep these three files during make clean
85no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)
86