[yocto] [PATCH 1/1] ddimage: Add script for writing images to boot media

[Darren Hart]

Fixes [YOCTO #1806]

Standard practice is to use the Linux "dd" command to write images to boot
media. This can be error prone and the results of sloppy usage can be
disastrous. Locating the device you want to use is a clumsy process, especially
on a headless build system.

The ddimage script does the following:

o Check the image and device exist
o Check the device is writable
o Compare the device to a blacklist and abort if it's listed
  Blacklist defaults to "/dev/sda"
o Display useful identifying information about the image and device
o Prompt the user before commencing the write

The output looks something like this:

$ sudo ~/bin/ddimage tmp/deploy/images/core-image-sato-fri2-noemgd.hddimg /dev/sdk
Image details
=============
    image: `tmp/deploy/images/core-image-sato-fri2-noemgd.hddimg' -> `core-image-sato-fri2-noemgd-20111202214038.hddimg'
     size: 318568448 bytes
 modified: 2011-12-02 13:45:05.298897861 -0800
     type: x86 boot sector, code offset 0x58, OEM-ID "SYSLINUX", sectors/cluster 16, root entries 512, Media descriptor 0xf8, sectors/FAT 152, heads 64, hidden sectors 32, sectors 622204 (volumes > 32 MB) , serial number 0x4ed946e0, label: "boot       ", FAT (16 bit)

Device details
==============
  device: /dev/sdk
  vendor: Kingston
   model: DT 101 G2

Write tmp/deploy/images/core-image-sato-fri2-noemgd.hddimg to /dev/sdk [y/N]? y
Writing image...
303+1 records in
303+1 records out
318568448 bytes (319 MB) copied, 53.6766 s, 5.9 MB/s

Signed-off-by: Darren Hart <dvhart at linux.intel.com>
CC: Dexuan Cui <dexuan.cui at intel.com>
CC: Joshua Lock <josh at linux.intel.com>
CC: Kishore K Bodke <kishore.k.bodke at intel.com>
---
 scripts/contrib/ddimage |   87 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 87 insertions(+), 0 deletions(-)
 create mode 100755 scripts/contrib/ddimage

diff --git a/scripts/contrib/ddimage b/scripts/contrib/ddimage
new file mode 100755
index 0000000..2cba9b2
--- /dev/null
+++ b/scripts/contrib/ddimage
@@ -0,0 +1,87 @@
+#!/bin/sh
+
+#BLACKLIST_DEVICES="/dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde"
+BLACKLIST_DEVICES="/dev/sda"
+
+# 1MB blocksize
+BLOCKSIZE=1048576
+
+function usage() {
+	echo "Usage: $(basename $0) IMAGE DEVICE"
+}
+
+function image_details() {
+	IMG=$1
+	echo "Image details"
+	echo "============="
+	echo "    image: $(stat --printf '%N\n' $IMG)"
+	echo "     size: $(stat -L --printf '%s bytes\n' $IMG)"
+	echo " modified: $(stat -L --printf '%y\n' $IMG)"
+	echo "     type: $(file -L -b $IMG)"
+	echo ""
+}
+
+function device_details() {
+	DEV=$1
+	BLOCK_SIZE=512
+
+	echo "Device details"
+	echo "=============="
+	echo "  device: $DEVICE"
+	if [ -f "/sys/class/block/$DEV/device/vendor" ]; then
+		echo "  vendor: $(cat /sys/class/block/$DEV/device/vendor)"
+	else
+		echo "  vendor: UNKOWN"
+	fi
+	if [ -f "/sys/class/block/$DEV/device/model" ]; then
+		echo "   model: $(cat /sys/class/block/$DEV/device/model)"
+	else
+		echo "   model: UNKNOWN"
+	fi
+	if [ -f "/sys/class/block/$DEV/size" ]; then
+		echo "    size: $[$(cat /sys/class/block/$DEV/size)*BLOCK_SIZE] bytes"
+	else
+		echo "    size: UNKNOWN"
+	fi
+	echo ""
+}
+
+if [ $# -ne 2 ]; then
+	usage
+	exit 1
+fi
+
+IMAGE=$1
+DEVICE=$2
+
+if [ ! -e "$IMAGE" ]; then
+	echo "ERROR: Image $IMAGE does not exist"
+	usage
+	exit 1
+fi
+
+
+if [ "${BLACKLIST_DEVICES/${DEVICE}/ERROR}" != "$BLACKLIST_DEVICES" ]; then
+	echo "ERROR: Device $DEVICE is blacklisted"
+	exit 1
+fi
+
+if [ ! -w "$DEVICE" ]; then
+	echo "ERROR: Device $DEVICE does not exist or is not writable"
+	usage
+	exit 1
+fi
+
+image_details $IMAGE
+device_details $(basename $DEVICE)
+
+echo -n "Write $IMAGE to $DEVICE [y/N]? "
+read RESPONSE
+if [ "$RESPONSE" != "y" ]; then
+	echo "Write aborted"
+	exit 0
+fi
+
+echo "Writing image..."
+dd if="$IMAGE" of="$DEVICE" bs="$BLOCKSIZE"
+sync
-- 
1.7.6.5