Is it possible to hack the 39gs?

[Claudio L.]

(08-19-2014 08:34 AM)Waon Shinyoe Wrote:  

(08-19-2014 07:31 AM)walter b Wrote:  Waon, xiè xiè ni(3) - so it's a clone of the 39gs in almost every aspect. Too large for my interest. May be interesting for others.

d

Hmm that's not a clone! But 39gs ITSELF! The hardware is confirmed the same. And we are just trying to flash a third-party firmware.
Thanks for all the enthusiastic guys and reply!

Here's an old page where there's a memory map of how things are in a hp49G+, the memory map would be almost identical on the 39gs.

http://lebonpoint.chez-alice.fr/hp49gp/reverse.htm

Basically, your firmware image will be loaded at address 0x4000, and the bootloader will jump into your code at 0x4018.
Exception handlers are pointing to 0x0 (in ROM), but the ROM relocates them to RAM (0x08000000), it's all handled transparently, so for all you care, just set your exception handlers in RAM and set your entry point at 0x4018, then you can do whatever you want.

Claudio