[source] image: when using the new image build code, gzip ext4 images by default

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/87b668765e1e987aebef8cf0aae657569b631477

commit 87b668765e1e987aebef8cf0aae657569b631477
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Jan 13 15:58:37 2017 +0100

    image: when using the new image build code, gzip ext4 images by default
    
    This reduces the amount of hacks in the makefile code.
    
    Remove the apm821xx code to do the same - it was broken and left both
    compressed and uncompressed images in $(BIN_DIR)
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/image.mk                     | 7 ++++++-
 target/linux/apm821xx/image/Makefile | 1 -
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/image.mk b/include/image.mk
index ab5b816..4bd923f 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -445,7 +445,8 @@ define Device/Build/kernel
 endef
 
 define Device/Build/image
-  $$(_TARGET): $(BIN_DIR)/$(call IMAGE_NAME,$(1),$(2))
+  GZ_SUFFIX := $(if $(filter %dtb %gz,$(2)),,$(if $(and $(findstring ext4,$(1)),$(CONFIG_TARGET_IMAGES_GZIP)),.gz))
+  $$(_TARGET): $(BIN_DIR)/$(call IMAGE_NAME,$(1),$(2))$$(GZ_SUFFIX)
   $(eval $(call Device/Export,$(KDIR)/tmp/$(call IMAGE_NAME,$(1),$(2)),$(1)))
   ROOTFS/$(1)/$(3) := \
 	$(KDIR)/root.$(1)$$(strip \
@@ -462,6 +463,10 @@ define Device/Build/image
 	$$(call concat_cmd,$(if $(IMAGE/$(2)/$(1)),$(IMAGE/$(2)/$(1)),$(IMAGE/$(2))))
 
   .IGNORE: $(BIN_DIR)/$(call IMAGE_NAME,$(1),$(2))
+
+  $(BIN_DIR)/$(call IMAGE_NAME,$(1),$(2)).gz: $(KDIR)/tmp/$(call IMAGE_NAME,$(1),$(2))
+	gzip -c -9n $$^ > $$@
+
   $(BIN_DIR)/$(call IMAGE_NAME,$(1),$(2)): $(KDIR)/tmp/$(call IMAGE_NAME,$(1),$(2))
 	cp $$^ $$@
 
diff --git a/target/linux/apm821xx/image/Makefile b/target/linux/apm821xx/image/Makefile
index 0ee9cdc..0ded83d 100644
--- a/target/linux/apm821xx/image/Makefile
+++ b/target/linux/apm821xx/image/Makefile
@@ -232,7 +232,6 @@ endef
 
 define Build/hdd-img
 	./mbl_gen_hdd_img.sh $@ $@.boot $(IMAGE_ROOTFS)
-	$(if $(CONFIG_TARGET_IMAGES_GZIP),gzip -9n -c $@ > $(BIN_DIR)/$(notdir $@).gz)
 endef
 
 define Device/MyBookLiveDefault