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 asm-offsets.h (may need bounds.h)
   6 # 3) Check for missing system calls
   7
   8 # Default sed regexp - multiline due to syntax constraints
   9 define sed-y
  10         "/^->/{s:->#\(.*\):/* \1 */:; \
  11         s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
  12         s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
  13         s:->::; p;}"
  14 endef
  15
  16 # Use filechk to avoid rebuilds when a header changes, but the resulting file
  17 # does not
  18 define filechk_offsets
  19         (set -e; \
  20          echo "#ifndef $2"; \
  21          echo "#define $2"; \
  22          echo "/*"; \
  23          echo " * DO NOT MODIFY."; \
  24          echo " *"; \
  25          echo " * This file was generated by Kbuild"; \
  26          echo " */"; \
  27          echo ""; \
  28          sed -ne $(sed-y); \
  29          echo ""; \
  30          echo "#endif" )
  31 endef
  32
  33 #####
  34 # 1) Generate bounds.h
  35
  36 bounds-file := include/generated/bounds.h
  37
  38 always  := $(bounds-file)
  39 targets := kernel/bounds.s
  40
  41 # We use internal kbuild rules to avoid the "is up to date" message from make
  42 kernel/bounds.s: kernel/bounds.c FORCE
  43         $(Q)mkdir -p $(dir $@)
  44         $(call if_changed_dep,cc_s_c)
  45
  46 $(obj)/$(bounds-file): kernel/bounds.s FORCE
  47         $(call filechk,offsets,__LINUX_BOUNDS_H__)
  48
  49 #####
  50 # 2) Generate asm-offsets.h
  51 #
  52
  53 offsets-file := include/generated/asm-offsets.h
  54
  55 always  += $(offsets-file)
  56 targets += arch/$(SRCARCH)/kernel/asm-offsets.s
  57
  58 # We use internal kbuild rules to avoid the "is up to date" message from make
  59 arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
  60                                       $(obj)/$(bounds-file) FORCE
  61         $(Q)mkdir -p $(dir $@)
  62         $(call if_changed_dep,cc_s_c)
  63
  64 $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
  65         $(call filechk,offsets,__ASM_OFFSETS_H__)
  66
  67 #####
  68 # 3) Check for missing system calls
  69 #
  70
  71 always += missing-syscalls
  72 targets += missing-syscalls
  73
  74 quiet_cmd_syscalls = CALL    $<
  75       cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
  76
  77 missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
  78         $(call cmd,syscalls)
  79
  80 # Keep these two files during make clean
  81 no-clean-files := $(bounds-file) $(offsets-file)