I like to play with the BeagleBone Black (BBB) board. Sometimes I need to edit or add files to the image before running on the board so it's useful to be able to mount the image directly on my Linux PC to work on it.

First download the image from http://beagleboard.org/latest-images. To download and use a BBB image you can follow the instruction on the post: "Getting started with BeagleBone Black".

After you extracted the image you must use fdisk to find the offset we'll use to mount the image partition:

fdisk bone-debian-8.2-console-armhf-2015-11-29-2gb.img

Press 'p' to print image detail and you get:

Command (m for help): p

Disk bone-debian-8.2-console-armhf-2015-11-29-2gb.img: 1782 MB, 1782579200 bytes
184 heads, 31 sectors/track, 610 cylinders, total 3481600 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
Disk identifier: 0x77b67e54

                                           Device Boot      Start         End      Blocks   Id  System
bone-debian-8.2-console-armhf-2015-11-29-2gb.img1   *        2048     3481599     1739776   83  Linux

Command (m for help): 

you need the partition start sector: 2048 . Then you must multiply it with the sector size (512):

2048 * 512 = 1048576

that number must be used as offset to mount the image:

mkdir /mnt/bbb-image
mount -o loop,offset=1048576 bone-debian-8.2-console-armhf-2015-11-29-2gb.img /mnt/bbb-image

That's all.

Now whatever you do in the mounted partition will be available when you'll run the image on a real BBB.

For example I usually mount the image partition as explained to have a local sysroot to build Qt libs for my BBB. In a next article I'll explain better how to built Qt.