fs/iso9660: convert to the filesystem infrastructure

This commit converts the iso9660 logic to the common rootfs
infrastructure. What previously prevented it from being converted is
that the iso9660 logic needed to remove a temporary folder after the
image has been created.

However, since Buildroot typically keeps build artefacts around, this
commit changes the logic to keep this temporary folder around. Thanks
to this change, converting to the common rootfs infrastructure becomes
possible.

In addition, the temporary folder is renamed from $(BUILD_DIR)/iso9660
to the more descriptive $(BUILD_DIR)/rootfs-iso9660.tmp.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

fs/iso9660/iso9660.mk

@@ -2,59 +2,53 @@
 #
 # Build the iso96600 root filesystem image
 #
-# Cannot be converted to the ROOTFS_TARGET infrastructure, because of
-# the temporary construction in ISO9660_TARGET_DIR.
-#
 ################################################################################
 
-ISO9660_TARGET_DIR = $(BUILD_DIR)/iso9660
+ISO9660_TARGET_DIR = $(BUILD_DIR)/rootfs-iso9660.tmp
 ISO9660_BOOT_MENU := $(call qstrip,$(BR2_TARGET_ROOTFS_ISO9660_BOOT_MENU))
 
 ROOTFS_ISO9660_DEPENDENCIES = grub host-cdrkit host-fakeroot linux rootfs-cpio
 
-$(BINARIES_DIR)/rootfs.iso9660: $(ROOTFS_ISO9660_DEPENDENCIES)
-	@$(call MESSAGE,"Generating root filesystem image rootfs.iso9660")
-	$(INSTALL) -D -m 0644 $(GRUB_DIR)/stage2/stage2_eltorito \
-		$(ISO9660_TARGET_DIR)/boot/grub/stage2_eltorito
-	$(INSTALL) -D -m 0644 $(ISO9660_BOOT_MENU) \
-		$(ISO9660_TARGET_DIR)/boot/grub/menu.lst
-ifeq ($(BR2_TARGET_GRUB_SPLASH),)
-	$(SED) '/^splashimage/d' $(ISO9660_TARGET_DIR)/boot/grub/menu.lst
-else
+ifeq ($(BR2_TARGET_GRUB_SPLASH),y)
+define ROOTFS_ISO9660_SPLASHSCREEN
 	$(INSTALL) -D -m 0644 boot/grub/splash.xpm.gz \
 		$(ISO9660_TARGET_DIR)/splash.xpm.gz
+endef
+else
+define ROOTFS_ISO9660_SPLASHSCREEN
+	$(SED) '/^splashimage/d' $(ISO9660_TARGET_DIR)/boot/grub/menu.lst
+endef
 endif
-	$(INSTALL) -D -m 0644 $(LINUX_IMAGE_PATH) $(ISO9660_TARGET_DIR)/kernel
+
 ifeq ($(BR2_TARGET_ROOTFS_INITRAMFS),y)
+define ROOTFS_ISO9660_INITRD
 	$(SED) '/initrd/d'  $(ISO9660_TARGET_DIR)/boot/grub/menu.lst
+endef
 else
+define ROOTFS_ISO9660_INITRD
 	$(INSTALL) -D -m 0644 $(BINARIES_DIR)/rootfs.cpio$(ROOTFS_CPIO_COMPRESS_EXT) \
 		$(ISO9660_TARGET_DIR)/initrd
+endef
 endif
-	# Use fakeroot to pretend all target binaries are owned by root
-	rm -f $(FAKEROOT_SCRIPT)
-	echo "chown -h -R 0:0 $(ISO9660_TARGET_DIR)" >> $(FAKEROOT_SCRIPT)
-	# Use fakeroot so mkisofs believes the previous fakery
-	echo "$(HOST_DIR)/usr/bin/genisoimage -R -b boot/grub/stage2_eltorito -no-emul-boot " \
-		"-boot-load-size 4 -boot-info-table -o $@ $(ISO9660_TARGET_DIR)" \
-		>> $(FAKEROOT_SCRIPT)
-	chmod a+x $(FAKEROOT_SCRIPT)
-	$(HOST_DIR)/usr/bin/fakeroot -- $(FAKEROOT_SCRIPT)
-	-@rm -f $(FAKEROOT_SCRIPT)
-	-@rm -rf $(ISO9660_TARGET_DIR)
 
-rootfs-iso9660: $(BINARIES_DIR)/rootfs.iso9660
+define ROOTFS_ISO9660_PREPARATION
+	$(RM) -rf $(ISO9660_TARGET_DIR)
+	mkdir -p $(ISO9660_TARGET_DIR)
+	$(INSTALL) -D -m 0644 $(GRUB_DIR)/stage2/stage2_eltorito \
+		$(ISO9660_TARGET_DIR)/boot/grub/stage2_eltorito
+	$(INSTALL) -D -m 0644 $(ISO9660_BOOT_MENU) \
+		$(ISO9660_TARGET_DIR)/boot/grub/menu.lst
+	$(INSTALL) -D -m 0644 $(LINUX_IMAGE_PATH) $(ISO9660_TARGET_DIR)/kernel
+	$(ROOTFS_ISO9660_SPLASHSCREEN)
+	$(ROOTFS_ISO9660_INITRD)
+endef
 
-rootfs-iso9660-show-depends:
-	@echo $(ROOTFS_ISO9660_DEPENDENCIES)
+ROOTFS_ISO9660_PRE_GEN_HOOKS += ROOTFS_ISO9660_PREPARATION
 
-.PHONY: rootfs-iso9660 rootfs-iso9660-show-depends
+define ROOTFS_ISO9660_CMD
+	$(HOST_DIR)/usr/bin/genisoimage -R -b boot/grub/stage2_eltorito \
+		-no-emul-boot -boot-load-size 4 -boot-info-table \
+		-o $@ $(ISO9660_TARGET_DIR)
+endef
 
-################################################################################
-#
-# Toplevel Makefile options
-#
-################################################################################
-ifeq ($(BR2_TARGET_ROOTFS_ISO9660),y)
-TARGETS_ROOTFS += rootfs-iso9660
-endif
+$(eval $(call ROOTFS_TARGET,iso9660))