Copy an image file to the SD card
Given you have file with a name like e300.direct.xz and you need to copy it onto an SD card, there are a couple of methods. Copying the image onto the card has all the needed partition information, saving you from lots of potential errors, on the other hand it can be slower.
In the past we used the dd command like this:
$ xzdec e300.direct.xz $ sudo dd if=e300.direct of=/dev/sdX
where /dev/sdX is the device the card is mounted as. This works, but can be slow.
Recently, we have started working with the bmaptool (http://lwn.net/Articles/563355/) So lets install bmaptool and copy an image that way.
$ git clone git://git.infradead.org/users/dedekind/bmap-tools.git $ cd bmap-tools $ sudo python setup.py install
If you can't run git through your firewall, I places a tarball at https://dl.dropboxusercontent.com/u/14618236/bmap-tools-3.2.tar.gz.
Now you should be able to run bmaptool from your path.
$ sudo bmaptool copy e300.direct.xz /dev/sdX --nobmap
While writing this, I saw that it is possible bmaptool might install from http urls. I need to test this