[Ipodlinux-devel] ipod reverse engineering

[Samuel O. <or...@fa...>]

Hi guys,

I got a 2.4.24-uc0 + latest ipodlinux cvs booting on my 3G ipod this 
weekend. This is an impressive work !
I was even more impressed when I started to look at the code. IMHO, 
writing this code without documentation nor JTAG interface is not a 
piece of cake...
Since I now would like to contribute to this project, I need some kind 
of help. I am interested in adding some power management features to 
this kernel. Portalplayer claims that its chipset provides many power 
management hooks, but how can I get some informations about it, without 
having any useful PP5002 docs ?  More generally, how did you manage to 
reverse engineer this machine ? As an example, how did you manage to 
understand that, in order to set the CPU speed to 75 Mhz, you'd have to 
do this:

    outl(0x02, 0xcf005008);
    outl(0x55, 0xcf00500c);
    outl(0x6000, 0xcf005010);
    outl(24, 0xcf005018);
    outl(75, 0xcf00501c);

How did you know that you have to write to this specific ports ? Did you 
get all this information from Apple's firmware ?

Thanks in advance for your time and answers !

Cheers,
Samuel.