diff options
| -rwxr-xr-x | mkusbimg | 75 |
1 files changed, 26 insertions, 49 deletions
@@ -16,25 +16,6 @@ # You should have received a copy of the GNU General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. -# next_avail_loop() -# prints the next available loopback device -# returns 0 on success -# 1 on failure -# XXX: this is only necessary because -# the cryptoloop patch for losetup -# destroys losetup -f -next_avail_loop() -{ - for i in /dev/loop/*; do - echo $(losetup -a|cut -d':' -f1) | grep -q $i - if [ $? -eq 1 ]; then - echo $i - return 0 - fi - done - return 1 -} - # usage(exitvalue) # outputs a usage message and exits with value APPNAME=$(basename "${0}") @@ -50,52 +31,48 @@ if [ $# -ne 2 ]; then usage 1 fi -IMG="${2}" +DISKIMG="${2}" IMGROOT="${1}" -LOOPDEV=$(next_avail_loop) TMPDIR=$(mktemp -d) +FSIMG=$(mktemp) -# TODO: there are better ways to do this -# than adding 25% to the rootsize -# XXX: doesn't seem to boot if we cut it too -# close. even if everything fits... -# IMGSZ >= filesystem overhead + rootsize + 512bytes -# must hold or there will be insufficient space +# ext2 overhead's upper bound is 6% +# empirically tested up to 1GB rootsize=$(du -bs ${IMGROOT}|cut -f1) -IMGSZ=$(( (${rootsize}*5)/4 + 512 )) - -# create the image file -dd if=/dev/zero of="$IMG" bs="$IMGSZ" count=1 +IMGSZ=$(( (${rootsize}*106)/100/512 + 1)) # image size in sectors -# loop mount the disk image -losetup "$LOOPDEV" "$IMG" - -# create a partition table -# if this looks like voodoo, it's because it is -echo "63,,,*,"|sfdisk -uS "$LOOPDEV" +# create the filesystem image file +dd if=/dev/zero of="$FSIMG" bs=512 count="$IMGSZ" -# loop mount the partition we just made -# that magic number (offset in bytes to first partition) is more voodoo -losetup -d "$LOOPDEV" -losetup -o32256 "$LOOPDEV" "$IMG" - -# create a filesystem on our partition -mke2fs -m 0 "$LOOPDEV" +# create a filesystem on the image +mke2fs -m 0 -F "$FSIMG" # mount the filesystem and copy data -mount "$LOOPDEV" "$TMPDIR" +mount -o loop "$FSIMG" "$TMPDIR" cp -a "$IMGROOT"/* "$TMPDIR" -# unmount filesystem and loopback +# unmount filesystem umount "$TMPDIR" -losetup -d "$LOOPDEV" + +# add sectors 0-62, then glue together +dd if=/dev/zero of="$DISKIMG" bs=512 count=63 +cat "$FSIMG" >> "$DISKIMG" + +# create a partition table +# if this looks like voodoo, it's because it is +sfdisk -uS -f "$DISKIMG" << EOF +63,$IMGSZ,83,* +0,0,00 +0,0,00 +0,0,00 +EOF # install grub on the image grub --no-floppy --batch << EOF -device (hd0) $IMG +device (hd0) $DISKIMG root (hd0,0) setup (hd0) EOF # all done :) -rm -fr "$TMPDIR" +rm -fr "$TMPDIR" "$FSIMG" |