uboot: add support for patch files and URLs

The existing u-boot patch option only allowed directories to be
specified. This adds support for URLs using similar code as found
in linux/linux.mk. Local files are also handled now.

This change is useful for Intel Edison support, so that Intel's u-boot
patch can be downloaded rather than stored in the Buildroot source tree.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

boot/uboot/Config.in

@@ -79,6 +79,16 @@ config BR2_TARGET_UBOOT_CUSTOM_PATCH_DIR
 
 	  Most users may leave this empty
 
+config BR2_TARGET_UBOOT_PATCH
+	string "Custom U-Boot patches"
+	help
+	  A space-separated list of patches to apply to U-Boot.
+	  Each patch can be described as an URL, a local file path,
+	  or a directory. In the case of a directory, all files
+	  matching *.patch in the directory will be applied.
+
+	  Most users may leave this empty
+
 choice
 	prompt "U-Boot binary format"
 	default BR2_TARGET_UBOOT_FORMAT_BIN

boot/uboot/uboot.mk

@@ -89,6 +89,8 @@ endef
 
 UBOOT_POST_EXTRACT_HOOKS += UBOOT_COPY_OLD_LICENSE_FILE
 
+# Prior to Buildroot 2015.05, only patch directories were supported. New
+# configurations use BR2_TARGET_UBOOT_PATCH instead.
 ifneq ($(call qstrip,$(BR2_TARGET_UBOOT_CUSTOM_PATCH_DIR)),)
 define UBOOT_APPLY_CUSTOM_PATCHES
 	$(APPLY_PATCHES) $(@D) $(BR2_TARGET_UBOOT_CUSTOM_PATCH_DIR) \*.patch
@@ -97,6 +99,24 @@ endef
 UBOOT_POST_PATCH_HOOKS += UBOOT_APPLY_CUSTOM_PATCHES
 endif
 
+# Analogous code exists in linux/linux.mk. Basically, the generic
+# package infrastructure handles downloading and applying remote
+# patches. Local patches are handled depending on whether they are
+# directories or files.
+UBOOT_PATCHES = $(call qstrip,$(BR2_TARGET_UBOOT_PATCH))
+UBOOT_PATCH = $(filter ftp://% http://% https://%,$(UBOOT_PATCHES))
+
+define UBOOT_APPLY_LOCAL_PATCHES
+	for p in $(filter-out ftp://% http://% https://%,$(UBOOT_PATCHES)) ; do \
+		if test -d $$p ; then \
+			$(APPLY_PATCHES) $(@D) $$p \*.patch || exit 1 ; \
+		else \
+			$(APPLY_PATCHES) $(@D) `dirname $$p` `basename $$p` || exit 1; \
+		fi \
+	done
+endef
+UBOOT_POST_PATCH_HOOKS += UBOOT_APPLY_LOCAL_PATCHES
+
 define UBOOT_CONFIGURE_CMDS
 	$(TARGET_CONFIGURE_OPTS) 	\
 		$(MAKE) -C $(@D) $(UBOOT_MAKE_OPTS)		\