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 #####
  10 # 1) Generate bounds.h
  11
  12 bounds-file := include/generated/bounds.h
  13
  14 always  := $(bounds-file)
  15 targets := kernel/bounds.s
  16
  17 # We use internal kbuild rules to avoid the "is up to date" message from make
  18 kernel/bounds.s: kernel/bounds.c FORCE
  19         $(Q)mkdir -p $(dir $@)
  20         $(call if_changed_dep,cc_s_c)
  21
  22 $(obj)/$(bounds-file): kernel/bounds.s FORCE
  23         $(call filechk,offsets,__LINUX_BOUNDS_H__)
  24
  25 #####
  26 # 2) Generate timeconst.h
  27
  28 timeconst-file := include/generated/timeconst.h
  29
  30 targets += $(timeconst-file)
  31
  32 quiet_cmd_gentimeconst = GEN     $@
  33 define cmd_gentimeconst
  34         (echo $(CONFIG_HZ) | bc -q $< ) > $@
  35 endef
  36 define filechk_gentimeconst
  37         (echo $(CONFIG_HZ) | bc -q $< )
  38 endef
  39
  40 $(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE
  41         $(call filechk,gentimeconst)
  42
  43 #####
  44 # 3) Generate asm-offsets.h
  45 #
  46
  47 offsets-file := include/generated/asm-offsets.h
  48
  49 always  += $(offsets-file)
  50 targets += arch/$(SRCARCH)/kernel/asm-offsets.s
  51
  52 # We use internal kbuild rules to avoid the "is up to date" message from make
  53 arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
  54                                       $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
  55         $(Q)mkdir -p $(dir $@)
  56         $(call if_changed_dep,cc_s_c)
  57
  58 $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
  59         $(call filechk,offsets,__ASM_OFFSETS_H__)
  60
  61 #####
  62 # 4) Check for missing system calls
  63 #
  64
  65 always += missing-syscalls
  66 targets += missing-syscalls
  67
  68 quiet_cmd_syscalls = CALL    $<
  69       cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
  70
  71 missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
  72         $(call cmd,syscalls)
  73
  74 # Keep these three files during make clean
  75 no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)