board/common: Move README.md installation to separate make target

Author: wkz

board/common/Config.in

@@ -5,6 +5,7 @@ source "$BR2_EXTERNAL_INFIX_PATH/board/common/image/image-itb-aux/Config.in"
 source "$BR2_EXTERNAL_INFIX_PATH/board/common/image/image-itb-qcow/Config.in"
 source "$BR2_EXTERNAL_INFIX_PATH/board/common/image/image-itb-gns3a/Config.in"
 source "$BR2_EXTERNAL_INFIX_PATH/board/common/image/image-itb-rauc/Config.in"
+source "$BR2_EXTERNAL_INFIX_PATH/board/common/image/image-readme/Config.in"
 
 endmenu
 

board/common/image/image-readme/Config.in

@@ -0,0 +1,7 @@
+config IMAGE_README
+	bool "Install README.md in images"
+	default y
+	help
+	  Install a README.md with useful information about getting
+	  started with Infix in the images directory (thereby also
+	  including it in the resulting release tarball).

board/common/README.txt renamed to board/common/image/image-readme/README.md

@@ -0,0 +1,18 @@
+################################################################################
+#
+# image-readme
+#
+################################################################################
+
+IMAGE_README_DIR := $(pkgdir)
+
+image-readme: $(BINARIES_DIR)/README.md
+
+$(BINARIES_DIR)/README.md: $(IMAGE_README_DIR)/README.md
+	@$(call IXMSG,"Installing README.md")
+	@mkdir -p $(BINARIES_DIR)
+	@cp $< $@
+
+ifeq ($(IMAGE_README),y)
+TARGETS_ROOTFS += image-readme
+endif

board/common/image/image-readme/image-readme.mk

@@ -1,7 +1 @@
 #!/bin/sh
-
-# Only for regular builds, not bootloader-only builds
-if [ "$BR2_TARGET_ROOTFS_SQUASHFS" = "y" ]; then
-    # Quick intro for beginners, with links to more information
-    cp "$BR2_EXTERNAL_INFIX_PATH/board/common/README.txt" "$BINARIES_DIR/"
-fi