gemini: Generate harddisk image for DNS-313

This makes OpenWrt build an Ext2+Ext4 partitioned image
for the D-Link DNS-313 with two blank partitions, a boot
partition on /dev/sda3 and a rootfs partition on
/dev/sda4.

This uses the methods already used in apm821xx including
the tricks to convert the generated Ext2 filesystem
partition to version 1 so that the firmware bootloader
will properly recognize it.

We patch a bit around the build files to make sure we
get the rootfs size set and that genext2fs is properly
built.

Tested on the D-Link DNS-313.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
[Fixing and tricksing]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 50 insertions, 7 deletions

diff --git a/target/linux/gemini/Makefile b/target/linux/gemini/Makefile
index 7c573c7c6d..304e515980 100644
--- a/target/linux/gemini/Makefile
+++ b/target/linux/gemini/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=arm
 BOARD:=gemini
 BOARDNAME:=Cortina Systems CS351x
-FEATURES:=squashfs pci rtc usb dt gpio display
+FEATURES:=squashfs pci rtc usb dt gpio display ext4 rootfs-part boot-part
 CPU_TYPE:=fa526
 MAINTAINER:=Roman Yeryomin <roman@advem.lv>
 
diff --git a/target/linux/gemini/image/Makefile b/target/linux/gemini/image/Makefile
index a612cf706d..7fcac8051f 100644
--- a/target/linux/gemini/image/Makefile
+++ b/target/linux/gemini/image/Makefile
@@ -28,6 +28,7 @@ endef
 # the only real content.
 define Build/dns313-images
 	mkdir -p $@.tmp/.boot
+	chmod 755 $@.tmp/.boot
 
 	echo "dummy" > $@.tmp/dummyfile
 
@@ -38,9 +39,20 @@ define Build/dns313-images
 	dns313-header $(IMAGE_KERNEL) \
 		$@.tmp/.boot/zImage
 
-	tar --sort=name --owner=0 --group=0 --numeric-owner -czf $@ \
-		-C $@.tmp .boot \
-		$(if $(SOURCE_DATE_EPOCH),--mtime="@$(SOURCE_DATE_EPOCH)")
+	rm $@.tmp/dummyfile
+
+	genext2fs --block-size $(BLOCKSIZE:%k=%Ki) \
+		--size-in-blocks $$((1024 * $(CONFIG_TARGET_KERNEL_PARTSIZE))) \
+		--squash-uids \
+		--root $@.tmp $@.tmp-boot
+
+	# The device firmware needs revision 1 of EXT2
+	tune2fs -O filetype $@.tmp-boot
+	e2fsck -pDf $@.tmp-boot > /dev/null
+
+	./dns313_gen_hdd_img.sh $@ $@.tmp-boot $(IMAGE_ROOTFS) \
+		$(CONFIG_TARGET_KERNEL_PARTSIZE) \
+		$(CONFIG_TARGET_ROOTFS_PARTSIZE)
 
 	rm -rf $@.tmp
 endef
@@ -106,7 +118,8 @@ GEMINI_NAS_PACKAGES:=kmod-md-mod kmod-md-linear kmod-md-multipath \
 		kmod-fs-btrfs kmod-fs-cifs kmod-fs-nfs \
 		kmod-fs-nfsd kmod-fs-ntfs kmod-fs-reiserfs kmod-fs-vfat \
 		kmod-nls-utf8 kmod-usb-storage-extras \
-		samba36-server mdadm cfdisk fdisk e2fsprogs badblocks
+		samba36-server mdadm cfdisk fdisk e2fsprogs badblocks \
+		partx-utils
 
 define Device/dlink_dir-685
 	DEVICE_TITLE := D-Link DIR-685 Xtreme N Storage Router
@@ -123,8 +136,10 @@ define Device/dlink_dns-313
 	DEVICE_TITLE := D-Link DNS-313 1-Bay Network Storage Enclosure
 	DEVICE_DTS := gemini-dlink-dns-313
 	DEVICE_PACKAGES := $(GEMINI_NAS_PACKAGES)
-	IMAGES := bootpart.tar.gz
-	IMAGE/bootpart.tar.gz := dns313-images
+	BLOCKSIZE := 1k
+	FILESYSTEMS := ext4
+	IMAGES := factory.bin.gz
+	IMAGE/factory.bin.gz := dns313-images | gzip
 endef
 TARGET_DEVICES += dlink_dns-313
 
diff --git a/target/linux/gemini/image/dns313_gen_hdd_img.sh b/target/linux/gemini/image/dns313_gen_hdd_img.sh
new file mode 100755
index 0000000000..1eb2c7c575
--- /dev/null
+++ b/target/linux/gemini/image/dns313_gen_hdd_img.sh
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+set -x
+[ $# -eq 5 ] || {
+	echo "SYNTAX: $0 <file> <bootfs image> <rootfs image> <bootfs size> <rootfs size>"
+	exit 1
+}
+
+OUTPUT="$1"
+BOOTFS="$2"
+ROOTFS="$3"
+BOOTFSSIZE="$4"
+ROOTFSSIZE="$5"
+
+head=4
+sect=63
+
+# Create two empty partitions followed by the boot partition with
+# the ./boot/zImage and then the rootfs partition.
+set `ptgen -o $OUTPUT -h $head -s $sect -t 83 -n -p 0 -p 0 -p ${BOOTFSSIZE}M -p ${ROOTFSSIZE}M`
+
+BOOTOFFSET="$(($1 / 512))"
+BOOTSIZE="$(($2 / 512))"
+ROOTFSOFFSET="$(($3 / 512))"
+ROOTFSSIZE="$(($4 / 512))"
+
+dd bs=512 if="$BOOTFS" of="$OUTPUT" seek="$BOOTOFFSET" conv=notrunc
+dd bs=512 if="$ROOTFS" of="$OUTPUT" seek="$ROOTFSOFFSET" conv=notrunc