View partition table of disk.img:
fdisk -lu disk.img
Disk disk.img: 1.3 GiB, 1361051648 bytes, 2658304 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: 0x6f92008e Device Boot Start End Sectors Size Id Type disk.img1 8192 131071 122880 60M c W95 FAT32 (LBA) disk.img2 131072 2658303 2527232 1.2G 83 Linux
Mount partition by using start multiplied by sector size as offset
mount -o loop,offset=$((131072 * 512)) disk.img /mnt