Recovery

Recovering the Joggler

It is pretty hard to brick the joggler - you have to overwrite the internal nvram bootloader (not just the mmc partition 1 fat fs with the efi bootloaders on it)

Recovery is not trivial, but not that hard.

Getting EFI Shell Access

When the Joggler boots it runs an internal EFI which is capable of seeing both the mmc (internal flash) and external usb storage.

This shell can also see an external USB keyboard and will listen to it.

You will need:

• usb hub
• usb keyboard (ideally one with a caps-lock light)
• usb stick

Create a fat partition on the stick with:

\grub.efi
\grub.cfg
\efi\tools\Shell.efi
\Screen.efi

The ext3 partition should have a linux distro with a suitable kernel. I use MeeGo

Plug in the hub, keyboard & stick and apply power. The screen flashes and an O2 logo appears; moments later the caps-lock light appears. Tap the <esc> key rapidly for 5 secs.

Now type blind:

fs1:screen<return>

You should get a screen-full of text - press <escape>

You now have EFI shell prompt.

The EFI shell lets you look at the fat32 partitions and you can edit files (the builtin editor is quite good!)

This Minimal-efi-tools.zip file contains the required binaries.

Boot a recovery system

Starting from an EFI shell you'll need a linux image installed into the 2nd partition on the stick.

The grub entry will look something like:

menuentry "MeeGo" {
  # Set the root device for GNU/Linux.
  root=(hd0,2)
  # Load the kernel and initrd.
  # The rootdelay is needed to allow the USB stick to settle
#  linux /boot/bzImage rootdelay=10 root=/dev/sda2 acpi=force netconsole=@10.0.0.11/,@/
  linux /boot/bzImage rootdelay=10 root=/dev/sda2 acpi=force
#  initrd /boot/initrd
}