realview: create sd card image for qemu

enables a real rootfs with custom size

use qemu with:
qemu-system-arm -M realview-pbx-a9 \
-kernel openwrt-realview-vmlinux.elf \
-nographic -m 1024M \
-sd openwrt-realview-sdcard.img \
--append "console=ttyAMA0 root=/dev/mmcblk0p1"

modified script from brcm2708 target

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>

SVN-Revision: 46924

target/linux/realview/image/Makefile

@@ -21,7 +21,16 @@ endef
 
 define Image/Build
 	$(call Image/Build/$(1))
+	$(call Build/sdcard-img)
 	dd if=$(KDIR)/root.$(1) of=$(BIN_DIR)/$(IMG_PREFIX)-root.$(1) bs=128k conv=sync
 endef
 
+define Build/sdcard-img
+	./gen_realview_sdcard_img.sh \
+	$(BIN_DIR)/$(IMG_PREFIX)-$(PROFILE)sdcard.img \
+	$(KDIR)/root.ext4 \
+	$(CONFIG_TARGET_ROOTFS_PARTSIZE)
+endef
+
+
 $(eval $(call BuildImage))

target/linux/realview/image/gen_realview_sdcard_img.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+set -x
+[ $# -eq 3 ] || {
+    echo "SYNTAX: $0 <file> <rootfs image> <rootfs size>"
+    exit 1
+}
+
+OUTPUT="$1"
+ROOTFS="$2"
+ROOTFSSIZE="$3"
+
+head=4
+sect=63
+
+set `ptgen -o $OUTPUT -h $head -s $sect -l 4096 -t 83 -p ${ROOTFSSIZE}M`
+
+ROOTFSOFFSET="$(($1 / 512))"
+ROOTFSSIZE="$(($2 / 512))"
+
+dd bs=512 if="$ROOTFS" of="$OUTPUT" seek="$ROOTFSOFFSET" conv=notrunc
+
+