Stéphane Charette, stephanecharette@gmail.com
In a continuing series of posts on BeagleBone, I decided to look into the various BeagleBone images available. For reference, my previous BeagleBone posts include:
I'm assuming you've already downloaded a BB installation image file, or at the very least you know where to find the images. If not, the BB test images can be found at https://rcn-ee.com/rootfs/bb.org/testing/.
Mounting .iso disk images is relatively simple. Mounting the BeagleBone .img files is similar, but requires one additional step. The .img files are full disk images, so when mounting them you need to specify the byte offset to the filesystem in the first partition. This is what happens if you try to use the loopback device to mount one of the BB .img files:
To get this working correctly, find the offset using the file command:
At 512 bytes per sector, the start offset is 512 * 8192 = 4194304 bytes. So modify the usual mount command and specify the exact offset. For example, in the case above with a startsector value of 8192:
You can now fully explore and even modify the content of .img file.
Once finished, remember to unmount the loopback image:
At the time I wrote this post, the latest images from Robert C. Nelson are dated 2017-01-17: https://rcn-ee.com/rootfs/bb.org/testing/2017-01-17/. There are two main categories of BB images -- a text-mode console image, and a X11 graphical desktop image.
| Filename | X Desktop | Flasher Script (/opt/scripts/tools/eMMC/) |
Free Space | Description |
|---|---|---|---|---|
| bone-debian-8.7-iot-armhf-2017-01-17-4gb.img | no | none | 1.8 GiB | Base for Debian 8.7 console image. The flasher script at the end of /boot/uEnv.txt is commented out, and thus wont overwrite the eMMC on boot. |
| BBB-blank-debian-8.7-iot-armhf-2017-01-17-4gb.img | no | init-eMMC-flasher-v3.sh | 1.8 GiB | Debian 8.7 console image. The only difference is the flasher script on the last line in /boot/uEnv.txt. |
| BBBL-blank-debian-8.7-iot-armhf-2017-01-17-4gb.img | no | init-eMMC-flasher-v3-bbbl.sh | 1.8 GiB | Debian 8.7 console image. The only difference is the flasher script on the last line in /boot/uEnv.txt. |
| Filename | X Desktop | Flasher Script (/opt/scripts/tools/eMMC/) |
Free Space | Description |
|---|---|---|---|---|
| bone-debian-8.7-lxqt-4gb-armhf-2017-01-17-4gb.img | lxqt | none | 379 MiB | Base for Debian 8.7 with X11 desktop. The flasher script at the end of /boot/uEnv.txt is commented out, and thus wont overwrite the eMMC on boot. |
| BBBW-blank-debian-8.7-lxqt-4gb-armhf-2017-01-17-4gb.img | lxqt | init-eMMC-flasher-v3-bbbw.sh | 379 MiB | Debian 8.7 X11 desktop image. The only difference is the flasher script on the last line in /boot/uEnv.txt. |
| BBB-blank-debian-8.7-lxqt-4gb-armhf-2017-01-17-4gb.img | lxqt | init-eMMC-flasher-v3.sh | 379 MiB | Debian 8.7 X11 desktop image. The only difference is the flasher script on the last line in /boot/uEnv.txt. |
When I say the only difference between these builds is the last line of /boot/uEnv.txt, I mean it really is the only difference. I generated the MD5 hash of every file in the images and used diff to locate the differences:
In the end, the biggest difference is whether the installation image includes X11.
Most BeagleBone end users can ignore the images that start with bone-debian-... With the flasher script commented out, it is better to stick to the BBx-blank-debian-... installation images.