Create a loopback device file with lofiadm:
sol# /usr/sbin/lofiadm -a/img.iso
This will create, for example, /dev/lofi/1 . It can be mounted as follows:
sol# mount -F hsfs -o ro /dev/lofi/1 /mnt/dir1
In general, you can use following command too,
for who want to use short hand method,
sol# mount -F hsfs -o ro
`/usr/sbin/lofiadm -a/img.iso` /mnt/dir1