Zaurus
Some technical information about the Zaurus machines from http://linuxtogo.org/gowiki/LinuxDevices
zaurus-installer
For the Zaurus a special kernel+initramfs has been developed. This special-purpose kernel is small enough to be flashed on NAND and features a framebuffer graphical menu for the selection of boot media containing the kernel to be kexec'ed.
Multi-partition cards and lots of filesystems are supported. The kernels to be launched are searched for in /boot of each available partition. There is a also a configuration file (/boot/boot.cfg) which allows selection of other kernels, custom kernel command lines, and specifies the label and the icon for each instance.
How to install:
Just unpack zaurus-installer-YOURMACHINE.tar.gz on a free partition: the package contains the kexecboot-kernel and the updater.sh utility. Then proceed as usual for flashing (switch off, pull battery out, insert battery again, before inserting AC plug press OK+Power On. In the Japanese Menu select 4 and finally 3 for SD card or 4 for CF). Screenshot
For the SL-5500 (collie) and optionally for other Zaurus too, flashing is possible just using the routines of the original firmware: reset the unit, Press C, and D button during restart.
See: Flashing-collie