[v2] mkefidisk.sh: Allow using a loopback mounted file

Submitted by Jason Wessel on Sept. 27, 2013, 1:01 a.m. | Patch ID: 59055


Message ID 1380243680-13770-1-git-send-email-jason.wessel@windriver.com
State Accepted
Commit 254899824900f2e8c6a34d2ad1b8cbea91acb4ae
Headers show

Commit Message

Jason Wessel Sept. 27, 2013, 1:01 a.m.
It should be possible to generate a disk to a file using a loopback
device with mkefidisk.sh, which is useful for booting simulators.  To
make this possible the partitions for the loop back need to work
similarly to the mmc devices.  The mkfs.vfat also requires and
additional argument to force it to write to something other then a
real disk.

  qemu-img create -f raw bigdisk 4G
  dev=`sudo losetup -f`
  sudo losetup $dev bigdisk
  mkefidisk.sh $dev tmp-eglibc/deploy/images/qemux86/core-image-minimal-qemux86.hddimg /dev/sda
  sudo losetup -d $dev

  Also a bug was fixed in the mkefidisk.sh where if the disk you are
  writing to initially has an invalid label the size of the first
  partition will be computed incorrectly.  For the simulator disk
  creation this is generally always the case, but this can happen with
  real hardware as well.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
 scripts/contrib/mkefidisk.sh |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

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diff --git a/scripts/contrib/mkefidisk.sh b/scripts/contrib/mkefidisk.sh
index af06b4b..c86849d 100755
--- a/scripts/contrib/mkefidisk.sh
+++ b/scripts/contrib/mkefidisk.sh
@@ -134,6 +134,11 @@  fi
 # Partition $DEVICE
 DEVICE_SIZE=$(parted $DEVICE unit mb print | grep ^Disk | cut -d" " -f 3 | sed -e "s/MB//")
+# If the device size is not reported there may not be a valid label
+if [ "$DEVICE_SIZE" = "" ] ; then
+	parted $DEVICE mklabel msdos
+	DEVICE_SIZE=$(parted $DEVICE unit mb print | grep ^Disk | cut -d" " -f 3 | sed -e "s/MB//")
@@ -142,7 +147,7 @@  SWAP_START=$((ROOTFS_END))
 # MMC devices use a partition prefix character 'p'
-if [ ! "${DEVICE#/dev/mmcblk}" = "${DEVICE}" ]; then
+if [ ! "${DEVICE#/dev/mmcblk}" = "${DEVICE}" ] || [ ! "${DEVICE#/dev/loop}" = "${DEVICE}" ]; then
@@ -197,7 +202,12 @@  unmount_device
 echo ""
 echo "Formatting $BOOTFS as vfat..."
-mkfs.vfat $BOOTFS -n "efi"
+if [ ! "${DEVICE#/dev/loop}" = "${DEVICE}" ]; then
+	mkfs.vfat -I $BOOTFS -n "efi"
+	mkfs.vfat $BOOTFS -n "efi"
 echo "Formatting $ROOTFS as ext3..."
 mkfs.ext3 $ROOTFS -L "root"