I've just started work on attempting to port CHDK to the 102b firmware based on neszt's beta builds.
My current progress is as follows:
* Decompiled firmware with IDA following the wiki
* Updated makefile.inc defines
* Found a few of the many symbols required (not all yet)
* Compiled sample code
* Booted camera with new firmware
* Camera rebooted and running code in boot(), checked with LED blinking
* Camera finally boots and runs with CHDK loading code commented out
* CHDK GUI loads, keyboard code seems to work.
Status: Trying to figure out why the CHDK menu doesn't refresh properly.