o.k. closer...

I extracted the initfs.osso-RX-44.2007-49.tgz file from initfs_flasher and rewrote all of the /dev/mmcblk* nodes to match the root fs. Then I recreated the tgz file and ran initfs_flash.

Success! (mostly)

Now can boot to mmc and df shows the correct devices for the root filesystem (mmcblk1p2) and the external mmc (mmcblk1p1) (Yes, I'm booting to the external card. I'm hacking this thing a lot right now.. If I wear out the flash, I'd like to be able to replace it.)

However, df now shows that the /mnt/initfs device is /dev/mmcblk1p2 (or if booted from flash /dev/mtdblock4), and not /dev/root??? But /etc/mtab correctly shows /mnt/initfs as /dev/root in either case...

Interesting eh?

kernelpanic

As /dev/root is mounted read-only, I'm not too worried about it...