package/pkg-kconfig.mk

   1 ################################################################################
   2 # Kconfig package infrastructure
   3 #
   4 # This file implements an infrastructure that eases development of
   5 # package .mk files for packages that use kconfig for configuration files.
   6 # It is based on the generic-package infrastructure, and inherits all of its
   7 # features.
   8 #
   9 # See the Buildroot documentation for details on the usage of this
  10 # infrastructure.
  11 #
  12 ################################################################################
  13
  14 ################################################################################
  15 # inner-kconfig-package -- generates the make targets needed to support a
  16 # kconfig package
  17 #
  18 #  argument 1 is the lowercase package name
  19 #  argument 2 is the uppercase package name, including a HOST_ prefix
  20 #             for host packages
  21 #  argument 3 is the uppercase package name, without the HOST_ prefix
  22 #             for host packages
  23 #  argument 4 is the type (target or host)
  24 ################################################################################
  25
  26 define inner-kconfig-package
  27
  28 # Call the generic package infrastructure to generate the necessary
  29 # make targets.
  30 # Note: this must be done _before_ attempting to use $$($(2)_DIR) in a
  31 # dependency expression
  32 $(call inner-generic-package,$(1),$(2),$(3),$(4))
  33
  34 # Default values
  35 $(2)_KCONFIG_EDITORS ?= menuconfig
  36 $(2)_KCONFIG_OPTS ?=
  37 $(2)_KCONFIG_FIXUP_CMDS ?=
  38 $(2)_KCONFIG_FRAGMENT_FILES ?=
  39
  40 # The config file as well as the fragments could be in-tree, so before
  41 # depending on them the package should be extracted (and patched) first.
  42 #
  43 # Since those files only have a order-only dependency, make would treat
  44 # any missing one as a "force" target:
  45 #   https://www.gnu.org/software/make/manual/make.html#Force-Targets
  46 # and would forcibly any rule that depend on those files, causing a
  47 # rebuild of the kernel each time make is called.
  48 #
  49 # So, we provide a recipe that checks all of those files exist, to
  50 # overcome that standard make behaviour.
  51 #
  52 $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES): | $(1)-patch
  53         for f in $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES); do \
  54                 if [ ! -f "$$$${f}" ]; then \
  55                         printf "Kconfig fragment '%s' for '%s' does not exist\n" "$$$${f}" "$(1)"; \
  56                         exit 1; \
  57                 fi; \
  58         done
  59
  60 # The specified source configuration file and any additional configuration file
  61 # fragments are merged together to .config, after the package has been patched.
  62 # Since the file could be a defconfig file it needs to be expanded to a
  63 # full .config first. We use 'make oldconfig' because this can be safely
  64 # done even when the package does not support defconfigs.
  65 $$($(2)_DIR)/.config: $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
  66         support/kconfig/merge_config.sh -m -O $$(@D) \
  67                 $$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES)
  68         @yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
  69                 $$($(2)_KCONFIG_OPTS) oldconfig
  70
  71 # In order to get a usable, consistent configuration, some fixup may be needed.
  72 # The exact rules are specified by the package .mk file.
  73 define $(2)_FIXUP_DOT_CONFIG
  74         $$($(2)_KCONFIG_FIXUP_CMDS)
  75         @yes "" | $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
  76                 $$($(2)_KCONFIG_OPTS) oldconfig
  77         $$(Q)touch $$($(2)_DIR)/.stamp_kconfig_fixup_done
  78 endef
  79
  80 $$($(2)_DIR)/.stamp_kconfig_fixup_done: $$($(2)_DIR)/.config
  81         $$(call $(2)_FIXUP_DOT_CONFIG)
  82
  83 # Before running configure, the configuration file should be present and fixed
  84 $$($(2)_TARGET_CONFIGURE): $$($(2)_DIR)/.stamp_kconfig_fixup_done
  85
  86 # Only enable the foo-*config targets when the package is actually enabled.
  87 # Note: the variable $(2)_KCONFIG_VAR is not related to the kconfig
  88 # infrastructure, but defined by pkg-generic.mk. The generic infrastructure is
  89 # already called above, so we can effectively use this variable.
  90 ifeq ($$($$($(2)_KCONFIG_VAR)),y)
  91
  92 # FOO_KCONFIG_FILE is required
  93 ifeq ($$($(2)_KCONFIG_FILE),)
  94 $$(error Internal error: no value specified for $(2)_KCONFIG_FILE)
  95 endif
  96
  97 # Configuration editors (menuconfig, ...)
  98 #
  99 # We need to apply the configuration fixups right after a configuration
 100 # editor exits, so that it is possible to save the configuration right
 101 # after exiting an editor, and so the user always sees a .config file
 102 # that is clean wrt. our requirements.
 103 #
 104 # Because commands in $(1)_FIXUP_KCONFIG are probably using $(@D), we
 105 # fake it for the configurators (otherwise it is set to just '.', i.e.
 106 # the current directory where make is run, which happens to be in
 107 # $(TOPDIR), because the target of the rule is not an actual file, so
 108 # does not have any path component).
 109 #
 110 $$(addprefix $(1)-,$$($(2)_KCONFIG_EDITORS)): @D=$$($(2)_DIR)
 111 $$(addprefix $(1)-,$$($(2)_KCONFIG_EDITORS)): $$($(2)_DIR)/.stamp_kconfig_fixup_done
 112         $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
 113                 $$($(2)_KCONFIG_OPTS) $$(subst $(1)-,,$$@)
 114         rm -f $$($(2)_DIR)/.stamp_{kconfig_fixup_done,configured,built}
 115         rm -f $$($(2)_DIR)/.stamp_{target,staging,images}_installed
 116         $$(call $(2)_FIXUP_DOT_CONFIG)
 117
 118 # Saving back the configuration
 119 #
 120 # Ideally, that should directly depend on $$($(2)_DIR)/.stamp_kconfig_fixup_done,
 121 # but that breaks the use-case in PR-8156 (from a clean tree):
 122 #   make menuconfig           <- enable kernel, use an in-tree defconfig, save and exit
 123 #   make linux-menuconfig     <- enable/disable whatever option, save and exit
 124 #   make menuconfig           <- change to use a custom defconfig file, set a path, save and exit
 125 #   make linux-update-config  <- should save to the new custom defconfig file
 126 #
 127 # Because of that use-case, saving the configuration can *not* directly
 128 # depend on the stamp file, because it itself depends on the .config,
 129 # which in turn depends on the (newly-set an non-existent) custom
 130 # defconfig file.
 131 #
 132 # Instead, we use an PHONY rule that will catch that situation.
 133 #
 134 $(1)-check-configuration-done:
 135         @if [ ! -f $$($(2)_DIR)/.stamp_kconfig_fixup_done ]; then \
 136                 echo "$(1) is not yet configured"; \
 137                 exit 1; \
 138         fi
 139
 140 $(1)-savedefconfig: $(1)-check-configuration-done
 141         $$($(2)_MAKE_ENV) $$(MAKE) -C $$($(2)_DIR) \
 142                 $$($(2)_KCONFIG_OPTS) savedefconfig
 143
 144 # Target to copy back the configuration to the source configuration file
 145 # Even though we could use 'cp --preserve-timestamps' here, the separate
 146 # cp and 'touch --reference' is used for symmetry with $(1)-update-defconfig.
 147 $(1)-update-config: $(1)-check-configuration-done
 148         @$$(if $$($(2)_KCONFIG_FRAGMENT_FILES), \
 149                 echo "Unable to perform $(1)-update-config when fragment files are set"; exit 1)
 150         cp -f $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE)
 151         touch --reference $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE)
 152
 153 # Note: make sure the timestamp of the stored configuration is not newer than
 154 # the .config to avoid a useless rebuild. Note that, contrary to
 155 # $(1)-update-config, the reference for 'touch' is _not_ the file from which
 156 # we copy.
 157 $(1)-update-defconfig: $(1)-savedefconfig
 158         @$$(if $$($(2)_KCONFIG_FRAGMENT_FILES), \
 159                 echo "Unable to perform $(1)-update-defconfig when fragment files are set"; exit 1)
 160         cp -f $$($(2)_DIR)/defconfig $$($(2)_KCONFIG_FILE)
 161         touch --reference $$($(2)_DIR)/.config $$($(2)_KCONFIG_FILE)
 162
 163 endif # package enabled
 164
 165 .PHONY: \
 166         $(1)-update-config \
 167         $(1)-update-defconfig \
 168         $(1)-savedefconfig \
 169         $(1)-check-configuration-done \
 170         $$(addprefix $(1)-,$$($(2)_KCONFIG_EDITORS))
 171
 172 endef # inner-kconfig-package
 173
 174 ################################################################################
 175 # kconfig-package -- the target generator macro for kconfig packages
 176 ################################################################################
 177
 178 kconfig-package = $(call inner-kconfig-package,$(pkgname),$(call UPPERCASE,$(pkgname)),$(call UPPERCASE,$(pkgname)),target)