We have a 5D3 now and start on that since the 650D/t4i requires a firmware update to get started.
nonsense

I should be getting my EOS M within the next week, and I plan to have ML started on that well before canon releases a firmware update.
plan:
- use 5d3 dump (both cameras have Digic5) to map the bootloader functions for reading / writing the bootflag (like the method I had to use for the 5dc).
- blindly find the matching functions in the EOS M bootloader (all i need to do is find the LED address [brute force method]).
- check a few lines near cstart and verify that the boot code is identical to the 5d3 (expecting it to be).
- apply boot code to EOS M like it's done on the 5d3
It's like a challenge / game for me
