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 filechk_gentimeconst = echo $(CONFIG_HZ) | bc -q $<
  30
  31 $(timeconst-file): kernel/time/timeconst.bc FORCE
  32         $(call filechk,gentimeconst)
  33
  34 #####
  35 # 3) Generate asm-offsets.h
  36 #
  37
  38 offsets-file := include/generated/asm-offsets.h
  39
  40 always  += $(offsets-file)
  41 targets += arch/$(SRCARCH)/kernel/asm-offsets.s
  42
  43 arch/$(SRCARCH)/kernel/asm-offsets.s: $(timeconst-file) $(bounds-file)
  44
  45 $(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
  46         $(call filechk,offsets,__ASM_OFFSETS_H__)
  47
  48 #####
  49 # 4) Check for missing system calls
  50 #
  51
  52 always += missing-syscalls
  53 targets += missing-syscalls
  54
  55 quiet_cmd_syscalls = CALL    $<
  56       cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
  57
  58 missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
  59         $(call cmd,syscalls)
  60
  61 #####
  62 # 5) Generate constants for Python GDB integration
  63 #
  64
  65 extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
  66
  67 build_constants_py: $(timeconst-file) $(bounds-file)
  68         @$(MAKE) $(build)=scripts/gdb/linux $@
  69
  70 # Keep these three files during make clean
  71 no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)