Kbuild

   1 # SPDX-License-Identifier: GPL-2.0
   2 #
   3 # Kbuild for top-level directory of the kernel
   4 # This file takes care of the following:
   5 # 1) Generate bounds.h
   6 # 2) Generate timeconst.h
   7 # 3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
   8 # 4) Check for missing system calls
   9 # 5) Generate constants.py (may need bounds.h)
  10
  11 #####
  12 # 1) Generate bounds.h
  13
  14 bounds-file := include/generated/bounds.h
  15
  16 always  := $(bounds-file)
  17 targets := kernel/bounds.s
  18
  19 $(bounds-file): kernel/bounds.s FORCE
  20         $(call filechk,offsets,__LINUX_BOUNDS_H__)
  21
  22 #####
  23 # 2) Generate timeconst.h
  24
  25 timeconst-file := include/generated/timeconst.h
  26
  27 targets += $(timeconst-file)
  28
  29 define filechk_gentimeconst
  30         (echo $(CONFIG_HZ) | bc -q $< )
  31 endef
  32
  33 $(timeconst-file): kernel/time/timeconst.bc FORCE
  34         $(call filechk,gentimeconst)
  35
  36 #####
  37 # 3) Generate asm-offsets.h
  38 #
  39
  40 offsets-file := include/generated/asm-offsets.h
  41
  42 always  += $(offsets-file)
  43 targets += arch/$(SRCARCH)/kernel/asm-offsets.s
  44
  45 arch/$(SRCARCH)/kernel/asm-offsets.s: $(timeconst-file) $(bounds-file)
  46
  47 $(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
  48         $(call filechk,offsets,__ASM_OFFSETS_H__)
  49
  50 #####
  51 # 4) Check for missing system calls
  52 #
  53
  54 always += missing-syscalls
  55 targets += missing-syscalls
  56
  57 quiet_cmd_syscalls = CALL    $<
  58       cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
  59
  60 missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
  61         $(call cmd,syscalls)
  62
  63 #####
  64 # 5) Generate constants for Python GDB integration
  65 #
  66
  67 extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
  68
  69 build_constants_py: $(timeconst-file) $(bounds-file)
  70         @$(MAKE) $(build)=scripts/gdb/linux $@
  71
  72 # Keep these three files during make clean
  73 no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)