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 # 5) Generate constants.py (may need bounds.h)
   9
  10 #####
  11 # 1) Generate bounds.h
  12
  13 bounds-file := include/generated/bounds.h
  14
  15 always  := $(bounds-file)
  16 targets := kernel/bounds.s
  17
  18 # We use internal kbuild rules to avoid the "is up to date" message from make
  19 kernel/bounds.s: kernel/bounds.c FORCE
  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         $(call if_changed_dep,cc_s_c)
  56
  57 $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
  58         $(call filechk,offsets,__ASM_OFFSETS_H__)
  59
  60 #####
  61 # 4) Check for missing system calls
  62 #
  63
  64 always += missing-syscalls
  65 targets += missing-syscalls
  66
  67 quiet_cmd_syscalls = CALL    $<
  68       cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
  69
  70 missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
  71         $(call cmd,syscalls)
  72
  73 #####
  74 # 5) Generate constants for Python GDB integration
  75 #
  76
  77 extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
  78
  79 build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
  80         @$(MAKE) $(build)=scripts/gdb/linux $@
  81
  82 # Keep these three files during make clean
  83 no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)