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1# SPDX-License-Identifier: GPL-2.0
2#
3# Kbuild for top-level directory of the kernel
4
5# Prepare global headers and check sanity before descending into sub-directories
6# ---------------------------------------------------------------------------
7
8# Generate bounds.h
9
10bounds-file := include/generated/bounds.h
11
12targets := kernel/bounds.s
13
14$(bounds-file): kernel/bounds.s FORCE
15 $(call filechk,offsets,__LINUX_BOUNDS_H__)
16
17# Generate timeconst.h
18
19timeconst-file := include/generated/timeconst.h
20
21filechk_gentimeconst = echo $(CONFIG_HZ) | bc -q $<
22
23$(timeconst-file): kernel/time/timeconst.bc FORCE
24 $(call filechk,gentimeconst)
25
26# Generate asm-offsets.h
27
28offsets-file := include/generated/asm-offsets.h
29
30targets += arch/$(SRCARCH)/kernel/asm-offsets.s
31
32arch/$(SRCARCH)/kernel/asm-offsets.s: $(timeconst-file) $(bounds-file)
33
34$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
35 $(call filechk,offsets,__ASM_OFFSETS_H__)
36
37# Check for missing system calls
38
39quiet_cmd_syscalls = CALL $<
40 cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
41
42PHONY += missing-syscalls
43missing-syscalls: scripts/checksyscalls.sh $(offsets-file)
44 $(call cmd,syscalls)
45
46# Check the manual modification of atomic headers
47
48quiet_cmd_check_sha1 = CHKSHA1 $<
49 cmd_check_sha1 = \
50 if ! command -v sha1sum >/dev/null; then \
51 echo "warning: cannot check the header due to sha1sum missing"; \
52 exit 0; \
53 fi; \
54 if [ "$$(sed -n '$$s:// ::p' $<)" != \
55 "$$(sed '$$d' $< | sha1sum | sed 's/ .*//')" ]; then \
56 echo "error: $< has been modified." >&2; \
57 exit 1; \
58 fi; \
59 touch $@
60
61atomic-checks += $(addprefix $(obj)/.checked-, \
62 atomic-arch-fallback.h \
63 atomic-instrumented.h \
64 atomic-long.h)
65
66targets += $(atomic-checks)
67$(atomic-checks): $(obj)/.checked-%: include/linux/atomic/% FORCE
68 $(call if_changed,check_sha1)
69
70# A phony target that depends on all the preparation targets
71
72PHONY += prepare
73prepare: $(offsets-file) missing-syscalls $(atomic-checks)
74 @:
75
76# Ordinary directory descending
77# ---------------------------------------------------------------------------
78
79obj-y += init/
80obj-y += usr/
81obj-y += arch/$(SRCARCH)/
82obj-y += $(ARCH_CORE)
83obj-y += kernel/
84obj-y += certs/
85obj-y += mm/
86obj-y += fs/
87obj-y += ipc/
88obj-y += security/
89obj-y += crypto/
90obj-$(CONFIG_BLOCK) += block/
91obj-$(CONFIG_IO_URING) += io_uring/
92obj-$(CONFIG_RUST) += rust/
93obj-y += $(ARCH_LIB)
94obj-y += drivers/
95obj-y += sound/
96obj-$(CONFIG_SAMPLES) += samples/
97obj-$(CONFIG_NET) += net/
98obj-y += virt/
99obj-y += $(ARCH_DRIVERS)
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# Default sed regexp - multiline due to syntax constraints
11define sed-y
12 "/^->/{s:->#\(.*\):/* \1 */:; \
13 s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
14 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
15 s:->::; p;}"
16endef
17
18# Use filechk to avoid rebuilds when a header changes, but the resulting file
19# does not
20define filechk_offsets
21 (set -e; \
22 echo "#ifndef $2"; \
23 echo "#define $2"; \
24 echo "/*"; \
25 echo " * DO NOT MODIFY."; \
26 echo " *"; \
27 echo " * This file was generated by Kbuild"; \
28 echo " */"; \
29 echo ""; \
30 sed -ne $(sed-y); \
31 echo ""; \
32 echo "#endif" )
33endef
34
35#####
36# 1) Generate bounds.h
37
38bounds-file := include/generated/bounds.h
39
40always := $(bounds-file)
41targets := kernel/bounds.s
42
43# We use internal kbuild rules to avoid the "is up to date" message from make
44kernel/bounds.s: kernel/bounds.c FORCE
45 $(Q)mkdir -p $(dir $@)
46 $(call if_changed_dep,cc_s_c)
47
48$(obj)/$(bounds-file): kernel/bounds.s FORCE
49 $(call filechk,offsets,__LINUX_BOUNDS_H__)
50
51#####
52# 2) Generate timeconst.h
53
54timeconst-file := include/generated/timeconst.h
55
56targets += $(timeconst-file)
57
58quiet_cmd_gentimeconst = GEN $@
59define cmd_gentimeconst
60 (echo $(CONFIG_HZ) | bc -q $< ) > $@
61endef
62define filechk_gentimeconst
63 (echo $(CONFIG_HZ) | bc -q $< )
64endef
65
66$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE
67 $(call filechk,gentimeconst)
68
69#####
70# 3) Generate asm-offsets.h
71#
72
73offsets-file := include/generated/asm-offsets.h
74
75always += $(offsets-file)
76targets += arch/$(SRCARCH)/kernel/asm-offsets.s
77
78# We use internal kbuild rules to avoid the "is up to date" message from make
79arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
80 $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
81 $(Q)mkdir -p $(dir $@)
82 $(call if_changed_dep,cc_s_c)
83
84$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
85 $(call filechk,offsets,__ASM_OFFSETS_H__)
86
87#####
88# 4) Check for missing system calls
89#
90
91always += missing-syscalls
92targets += missing-syscalls
93
94quiet_cmd_syscalls = CALL $<
95 cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
96
97missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
98 $(call cmd,syscalls)
99
100#####
101# 5) Generate constants for Python GDB integration
102#
103
104extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
105
106build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
107 @$(MAKE) $(build)=scripts/gdb/linux $@
108
109# Keep these three files during make clean
110no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)