As too getting debian running on the 3100 ... I feel your pain, it was much more of an effort than the C1K for me to get debian on the unit. Here's the steps I took to get there.
In my experience I have found that the rootfs for PdaXrom 198 and the udated kernel.img's can't be flashed from the CF card without some effort. Where as they work fine from the SD card. In addition I found that the "emergency linux boot" console has a DEVIL of a time dealling with the internal drive. In my personal case it gave me fits for days before a kind soul pointed me in PdaXii13's way of pre-setting things up.
BIG FIRST - Restore the unit back to the basic setup (cf card with systc310.dbk), press "fn+d+m" and proceed to the nand restore options. Restore the nand.
Step two reflash the unit with PdaXii13, make sure once its installed that you grab bzip2 (ipkg install bzip2). If you have an SD card or CF card with thats at 256MB or bigger we can continue to the next step.
Step three; copy the rootfs provided
here. Fdisk the hda1 into one full partition, mkfs.ext3 on it and the remount it. Copy the zaurus_eabi_rootfs_071201.tar.bz2 file to the hda partition. cd into the root of the hda partition and use "tar jxvf zaurus_eabi_rootfs_071201.tar.bz2" to uncompress the image and form the root you need. Make any changes prescribed in the wiki here. Once all set, proceed on. Make sure to cd into the hda1 dev directory and MAKEDEV console.
Step four; copy the u-boot files to the root of the SD card, flash u-boot from a fat16 paritioned SD card (partition size of about 256MB should do fine). Once the solid lights go out, pull the power and SD card. Make a folder on the card called u-boot and move all of the uboot files into it.
Step five; copy the rootfs & pdax kernel to the root of the SD card, flash rootfs & kernel from the same fat16 partitioned SD card. Place the card back in, press "ok" and plug the power back in. Keep holding the ok button until it comes to the emergency menu. When asked answer "y" to the question and allow it to complete the flash of PdaX198. Once done it will reboot. Allow it too complete the reboot fully to the prompt. Once it does, make a folder on the SD card called "rootfs" and copy all of the pdaxrom files into it. Copy the autoboot.sh and this
kernel to the SD card, pull the power, press and hold "ok" and plug the power back in ... she will boot into emergency mode and ask a question, answer "y" and it will quickly flash your new kernel. The unit will reboot.
Note: I mention the older 2.6.22 kernel because it will boot straight too the hda debian partition without requiring you to press and hold keys. The newer kernels require you to press and hold a number key to boot into the hda1 partition. Once you have all up and running you can flash to one of the newer ones
Step six; Should boot through (YMMV)
