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)