package/pkg-kernel-module.mk

   1 ################################################################################
   2 # kernel module infrastructure for building Linux kernel modules
   3 #
   4 # This file implements an infrastructure that eases development of package
   5 # .mk files for out-of-tree Linux kernel modules. It should be used for all
   6 # packages that build a Linux kernel module using the kernel's out-of-tree
   7 # buildsystem, unless they use a complex custom buildsystem.
   8 #
   9 # The kernel-module infrastructure requires the packages that use it to also
  10 # use another package infrastructure. kernel-module only defines post-build
  11 # and post-install hooks. This allows the package to build both kernel
  12 # modules and/or user-space components (with any of the other *-package
  13 # infra).
  14 #
  15 # As such, it is to be used in conjunction with another *-package infra,
  16 # like so:
  17 #
  18 #   $(eval $(kernel-module))
  19 #   $(eval $(generic-package))
  20 #
  21 # Note: if the caller needs access to the kernel modules (either after they
  22 # are built or after they are installed), it will have to define its own
  23 # post-build/install hooks *after* calling kernel-module, but *before*
  24 # calling the other *-package infra, like so:
  25 #
  26 #   $(eval $(kernel-module))
  27 #   define FOO_MOD_TWEAK
  28 #       # do something
  29 #   endef
  30 #   FOO_POST_BUILD_HOOKS += FOO_MOD_TWEAK
  31 #   $(eval $(generic-package))
  32 #
  33 # Note: this infra does not check that the kernel is enabled; it is expected
  34 # to be enforced at the Kconfig level with proper 'depends on'.
  35 ################################################################################
  36
  37 ################################################################################
  38 # inner-kernel-module -- generates the make targets needed to support building
  39 # a kernel module
  40 #
  41 #  argument 1 is the lowercase package name
  42 #  argument 2 is the uppercase package name
  43 ################################################################################
  44
  45 define inner-kernel-module
  46
  47 # If the package is enabled, ensure the kernel will support modules
  48 ifeq ($$(BR2_PACKAGE_$(2)),y)
  49 LINUX_NEEDS_MODULES = y
  50 endif
  51
  52 # The kernel must be built first.
  53 $(2)_DEPENDENCIES += linux
  54
  55 # This is only defined in some infrastructures (e.g. autotools, cmake),
  56 # but not in others (e.g. generic). So define it here as well.
  57 $(2)_MAKE ?= $$(MAKE)
  58
  59 # If not specified, consider the source of the kernel module to be at
  60 # the root of the package.
  61 $(2)_MODULE_SUBDIRS ?= .
  62
  63 # Build the kernel module(s)
  64 # Force PWD for those packages that want to use it to find their
  65 # includes and other support files (Booo!)
  66 define $(2)_KERNEL_MODULES_BUILD
  67         @$$(call MESSAGE,"Building kernel module(s)")
  68         $$(foreach d,$$($(2)_MODULE_SUBDIRS), \
  69                 $$(LINUX_MAKE_ENV) $$($$(PKG)_MAKE) \
  70                         -C $$(LINUX_DIR) \
  71                         $$(LINUX_MAKE_FLAGS) \
  72                         $$($(2)_MODULE_MAKE_OPTS) \
  73                         PWD=$$(@D)/$$(d) \
  74                         M=$$(@D)/$$(d) \
  75                         modules$$(sep))
  76 endef
  77 $(2)_POST_BUILD_HOOKS += $(2)_KERNEL_MODULES_BUILD
  78
  79 # Install the kernel module(s)
  80 # Force PWD for those packages that want to use it to find their
  81 # includes and other support files (Booo!)
  82 define $(2)_KERNEL_MODULES_INSTALL
  83         @$$(call MESSAGE,"Installing kernel module(s)")
  84         $$(foreach d,$$($(2)_MODULE_SUBDIRS), \
  85                 $$(LINUX_MAKE_ENV) $$($$(PKG)_MAKE) \
  86                         -C $$(LINUX_DIR) \
  87                         $$(LINUX_MAKE_FLAGS) \
  88                         $$($(2)_MODULE_MAKE_OPTS) \
  89                         PWD=$$(@D)/$$(d) \
  90                         M=$$(@D)/$$(d) \
  91                         modules_install$$(sep))
  92 endef
  93 $(2)_POST_INSTALL_TARGET_HOOKS += $(2)_KERNEL_MODULES_INSTALL
  94
  95 endef
  96
  97 ################################################################################
  98 # kernel-module -- the target generator macro for kernel module packages
  99 ################################################################################
 100
 101 kernel-module = $(call inner-kernel-module,$(pkgname),$(call UPPERCASE,$(pkgname)))