magic update usbkey

Sridhar Dhanapalan sridhar at
Thu Feb 10 08:57:59 EST 2011

On 11 February 2011 00:26, Martin Langhoff <martin.langhoff at> wrote:
> On Thu, Feb 10, 2011 at 1:09 AM, Sridhar Dhanapalan
> <sridhar at> wrote:
>> We're also using a olpc.fth file to make some other things easier for
>> teachers. Since our XOs are developer unlocked, there's nothing
> Intriguing. What do you do with an olpc.fth that a teacher would need?

We wanted to allow teachers to easily:

  1. upgrade the firmware
  2. get our filesystem deployment key (skey) onto the XOs
  3. install our signed OS image
  4. NANDblast the image to other XOs (nb-secure)

The file structure on the USB drive looks like this:

|-- boot
|   |--
|   |-- olpc.fth
|   `--
|-- fs.zd

Step 1 is already handled by placing into /boot on a USB
drive. The others are handled by olpc.fth.

If you insert the USB drive into the XO and power-on, it will:

  1. install the firmware, then reboot
  2. install the skey (, then reboot

On the next reboot, the user gets a menu:

  Security key already installed.

  Press 1 to write the fs.zd operating system image from the USB drive
to the XO.
  Press 2 to start a NANDblaster broadcast of the signed fs.zd
operating system image from the USB drive.
  Press any other key to power off the XO.

Then the teacher can pick 1 to flash their own XO. After the reboot,
they can pick 2 to start nb-secure.

On the children's XOs, you use the same USB stick to upgrade the
firmware and install the skey. As early adopters of the XO-1.5s, we
have many XOs that don't have NANDblaster-capable firmware. Then turn
them on again with the four game keys held to put them into
NANDblaster receive mode.

This is being developed at:


More information about the Devel mailing list