About two years ago I was working on a PowerPC Simulator/Emulator and got so far (where it executed a few million instructions) and then - for whatever reason - start executing a string table. Debugging said million assembly instructions put me off working on it again for a while.
I picked up the code again and got it compiling and running rather quickly and even noticed two rather large and glaring errors.
Firstly, the device I'm simulating is a Curtiss Wright (DY4) DMV-179 with a PowerPC 750 processor. The device uses a GT64130 memory controller which you can setup for big or little endian. This wasn't setup correctly so was copying from Flash memory to RAM in the wrong endianness.
Strangly enough, when said inverted instructions are executed, it goes bat-s**t crazy.
So, fixing that I've started to work on getting that fired up again and seeing if I can get it to the point where the firmware (aka bios) starts talking on the serial link. Should be interesting...