Operating system image installation methods

We use a few different methods to install operating system images.

installation method	what files are required	how to install	references
block signed	.zd and fs.zip	hold down the four game pad buttons and then turn on the laptop	Release notes
block unsigned	.zd alone	check if security is enabled, if so obtain developer key and disable-security, interrupt boot, then use the fs-update command	Release notes
nand signed	.img and fs.zip	hold down the four game pad buttons and then turn on the laptop	Release notes Clean Install Procedure Nandblaster_for_XO-1
nand unsigned	.img and .crc	check if security is enabled, if so obtain developer key and disable-security, interrupt boot, then use the copy-nand command	Release notes Clean Install Procedure Nandblaster_for_XO-1
nand partitioned	.dat and .img	check if security is enabled, if so obtain developer key and disable-security, interrupt boot, then use the update-nand command	Used by DebXO. Used by UBIFS experiments. See also Technical description.

The signed installation methods are the same for XO-4, XO-1.75, XO-1.5 and XO-1. This was by design, since we do not wish to increase the training burden for the deployment teams, who will typically sign their builds and install deployment keys.

The unsigned installation methods depend on the type of internal storage. XO-1 has raw NAND Flash. XO-1.5, XO-1.75 and XO-4 have microSD or eMMC managed Flash.

See also Firmware/Storage.