Get informations about partitions in image:
fdisk -lu Udoo.img
Output may looked like this:
Disk Udoo.img: 7,4 GiB, 7948206080 bytes, 15523840 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xbf31fe90 Device Boot Start End Sectors Size Id Type Udoo.img1 8192 15523839 15515648 7,4G 83 Linux
On my Udoo.img I have one partition, when I want mount this partition need to know position in bytes, where start the partition in image file. My partition start on 8192 block, default block size is 512B then start position is 8192 * 512B = 4194304B
Now we can mount partition:
mount -o ro,loop,offset=4194304 Udoo.img /mnt/temp