[source] ar71xx: clean up SEAMA image build code

[LEDE Commits]

neoraider pushed a commit to source.git, branch master:
https://git.lede-project.org/fce0b5d8938ae900057766679139e6eb8b0f8c54

commit fce0b5d8938ae900057766679139e6eb8b0f8c54
Author: Matthias Schiffer <mschiffer at universe-factory.net>
AuthorDate: Tue Oct 11 20:32:24 2016 +0200

    ar71xx: clean up SEAMA image build code
    
    Split seama-factory and seama-sysupgrade into smaller pieces (similar to
    the ramips code) to make the image generation more flexible.
    
    Also use standard pad-offset instead of adding a block of zeros at the
    beginning of the image that is later cut off again. Standard pad-rootfs can
    be used as the seal header doesn't contain an image size or checksum.
    
    Signed-off-by: Matthias Schiffer <mschiffer at universe-factory.net>
---
 target/linux/ar71xx/image/generic.mk | 52 +++++++++++++-----------------------
 1 file changed, 18 insertions(+), 34 deletions(-)

diff --git a/target/linux/ar71xx/image/generic.mk b/target/linux/ar71xx/image/generic.mk
index 0307b26..d1e847b 100644
--- a/target/linux/ar71xx/image/generic.mk
+++ b/target/linux/ar71xx/image/generic.mk
@@ -472,51 +472,35 @@ endef
 TARGET_DEVICES += hiwifi-hc6361
 
 
-# The pre-filled 64 bytes consist of
-# - 28 bytes seama_header
-# - 36 bytes of META data (4-bytes aligned)
-define Build/seama-factory
-	( dd if=/dev/zero bs=64 count=1; cat $(IMAGE_KERNEL) ) >$@.loader.tmp
-	( dd if=$@.loader.tmp bs=64k conv=sync; dd if=$(IMAGE_ROOTFS) ) >$@.tmp.0
-	tail -c +65 $@.tmp.0 >$@.tmp.1
-	$(STAGING_DIR_HOST)/bin/seama \
-		-i $@.tmp.1 \
-		-m "dev=/dev/mtdblock/1" -m "type=firmware"
-	$(STAGING_DIR_HOST)/bin/seama \
-		-s $@ \
-		-m "signature=$(1)" \
-		-i $@.tmp.1.seama
-	rm -f $@.loader.tmp $@.tmp.*
-endef
-
-define Build/seama-sysupgrade
-	$(STAGING_DIR_HOST)/bin/seama \
-		-i $(IMAGE_KERNEL) \
-		-m "dev=/dev/mtdblock/1" -m "type=firmware"
-	( dd if=$(IMAGE_KERNEL).seama bs=64k conv=sync; dd if=$(IMAGE_ROOTFS) ) >$@
-	rm -f $(IMAGE_KERNEL).seama
-endef
-
-define Build/seama-initramfs
-	$(STAGING_DIR_HOST)/bin/seama \
-		-i $@ \
-		-m "dev=/dev/mtdblock/1" -m "type=firmware"
+define Build/seama
+	$(STAGING_DIR_HOST)/bin/seama -i $@ $(if $(1),$(1),-m "dev=/dev/mtdblock/1" -m "type=firmware")
 	mv $@.seama $@
 endef
 
-define Build/seama-pad-rootfs
-	$(STAGING_DIR_HOST)/bin/padjffs2 $(IMAGE_ROOTFS) -c 64 >>$@
+define Build/seama-seal
+	$(call Build/seama,-s $@.seama $(1))
 endef
 
 define Device/seama
   CONSOLE := ttyS0,115200
   LOADER_TYPE := bin
+  BLOCKSIZE := 64k
   KERNEL := kernel-bin | lzma | loader-kernel-cmdline | lzma
-  KERNEL_INITRAMFS := kernel-bin | patch-cmdline | lzma | seama-initramfs
+  KERNEL_INITRAMFS := kernel-bin | patch-cmdline | lzma | seama
   KERNEL_INITRAMFS_SUFFIX = $$(KERNEL_SUFFIX).seama
   IMAGES := sysupgrade.bin factory.bin
-  IMAGE/sysupgrade.bin := seama-sysupgrade $$$$(SEAMA_SIGNATURE) | seama-pad-rootfs | check-size $$$$(IMAGE_SIZE)
-  IMAGE/factory.bin := seama-factory $$$$(SEAMA_SIGNATURE) | seama-pad-rootfs | check-size $$$$(IMAGE_SIZE)
+
+  # 64 bytes offset:
+  # - 28 bytes seama_header
+  # - 36 bytes of META data (4-bytes aligned)
+  IMAGE/default := append-kernel | pad-offset $$$$(BLOCKSIZE) 64 | append-rootfs
+  IMAGE/sysupgrade.bin := \
+	$$(IMAGE/default) | seama | pad-rootfs | \
+	check-size $$$$(IMAGE_SIZE)
+  IMAGE/factory.bin := \
+	$$(IMAGE/default) | seama | pad-rootfs | \
+	seama-seal -m "signature=$$$$(SEAMA_SIGNATURE)" | \
+	check-size $$$$(IMAGE_SIZE)
   SEAMA_SIGNATURE :=
   DEVICE_VARS += SEAMA_SIGNATURE
 endef