A small loopback mount utility using FUSE.
Mainly intended to allow creating of virtual disk images by giving specific offset/size access so that mke2fs can be run on less than the entire file.
Once a virtual disk image has been partitioned and had the filesystems created, fuseext2 can be used to mount it.
Example:
# Create a new file for our disk image (300M in size)
truncate -s 300M mydisk.img
# Use fdisk to create a 100M partition
# If we use 64/32/512 for heads/sectors/sectorsize cylinders=$DISK_SIZE_IN_M
/sbin/fdisk -c -u -C 300 -H 64 -S 32 -b 512 mydisk.img << EOF
n
p
1
+100M
a
w
EOF
# Use fdisk to give us the correct offset and size values to use with fuseloop
line=`/sbin/fdisk -c -u -l -C 300 -H 64 -S 32 -b 512 mydisk.img | grep mydisk.img | grep Linux | sed 's/\*//'`
set -- $line
sectorsize=512
offs=$(($2*$sectorsize))
size=$((($3-$2)*$sectorsize))
# Random name for partition dev
part=part.$$
touch "$part"
# Use fuseloop to expose the partition as an individual file/device
./fuseloop -O "$offs" -S "$size" mydisk.img "$part"
# Create the file system
/sbin/mke2fs -F "$part"
# If you want, you can install the SYSLinux MBR to get a bootable image (remember to mark partition 1 as 'active' too!)
dd if=/usr/lib/syslinux/mbr/mbr.bin of=mydisk.img conv=notrunc
# With the filesystem laid down on the partition, fuseext2 can be used to mount it
mkdir mnt
fuseext2 -o rw,force $part mnt
# ... copy file to partition ...
# Unmount the partition
fusermount -u "$part"
fusermount -u mnt
# Clean up the partition file we mounted on
rm -f "$part"
rmdir mnt