LXR linux/Kbuild

   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
   9# Default sed regexp - multiline due to syntax constraints
  10define sed-y
  11        "/^->/{s:->#\(.*\):/* \1 */:; \
  12        s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
  13        s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
  14        s:->::; p;}"
  15endef
  16
  17# Use filechk to avoid rebuilds when a header changes, but the resulting file
  18# does not
  19define filechk_offsets
  20        (set -e; \
  21         echo "#ifndef $2"; \
  22         echo "#define $2"; \
  23         echo "/*"; \
  24         echo " * DO NOT MODIFY."; \
  25         echo " *"; \
  26         echo " * This file was generated by Kbuild"; \
  27         echo " */"; \
  28         echo ""; \
  29         sed -ne $(sed-y); \
  30         echo ""; \
  31         echo "#endif" )
  32endef
  33
  34#####
  35# 1) Generate bounds.h
  36
  37bounds-file := include/generated/bounds.h
  38
  39always  := $(bounds-file)
  40targets := kernel/bounds.s
  41
  42# We use internal kbuild rules to avoid the "is up to date" message from make
  43kernel/bounds.s: kernel/bounds.c FORCE
  44        $(Q)mkdir -p $(dir $@)
  45        $(call if_changed_dep,cc_s_c)
  46
  47$(obj)/$(bounds-file): kernel/bounds.s FORCE
  48        $(call filechk,offsets,__LINUX_BOUNDS_H__)
  49
  50#####
  51# 2) Generate timeconst.h
  52
  53timeconst-file := include/generated/timeconst.h
  54
  55targets += $(timeconst-file)
  56
  57quiet_cmd_gentimeconst = GEN     $@
  58define cmd_gentimeconst
  59        (echo $(CONFIG_HZ) | bc -q $< ) > $@
  60endef
  61define filechk_gentimeconst
  62        (echo $(CONFIG_HZ) | bc -q $< )
  63endef
  64
  65$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE
  66        $(call filechk,gentimeconst)
  67
  68#####
  69# 3) Generate asm-offsets.h
  70#
  71
  72offsets-file := include/generated/asm-offsets.h
  73
  74always  += $(offsets-file)
  75targets += arch/$(SRCARCH)/kernel/asm-offsets.s
  76
  77# We use internal kbuild rules to avoid the "is up to date" message from make
  78arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
  79                                      $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
  80        $(Q)mkdir -p $(dir $@)
  81        $(call if_changed_dep,cc_s_c)
  82
  83$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
  84        $(call filechk,offsets,__ASM_OFFSETS_H__)
  85
  86#####
  87# 4) Check for missing system calls
  88#
  89
  90always += missing-syscalls
  91targets += missing-syscalls
  92
  93quiet_cmd_syscalls = CALL    $<
  94      cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
  95
  96missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
  97        $(call cmd,syscalls)
  98
  99# Keep these three files during make clean
 100no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)
 101