This describes how to take an image file (origBBB.img) that has been extracted from a Beaglebone Black (BBB) – (see here for how to do that) – and shrink it so that it will fit onto a smaller SD card.

First we need to be able to inspect the file system locally.  We can inspect the image file with:

file origBBB.img
origBBB.img: x86 boot sector; partition 1: ID=0xc, active, starthead 1, startsector 63, 144522 sectors; partition 2: ID=0x83, starthead 45, startsector 147456, 6979584 sectors, code offset 0x0

Ok, so you’ve been playing with your BBB and you’ve installed this package and that package, oh and that package you forgot about.  So now you want to setup another BBB in exactly the same way but wait… oh no, what did you install again and how did you configure things… this could take some time.

That was me recently when I wanted to set up a second BBB.  I’d installed qt4-embedded on the eMMC as well as lots of other stuff and really didn’t want to start from scratch on another board.