On 28.03.2013, at 16:10, Fabien Chouteau wrote: > On 03/28/2013 12:46 PM, Alexander Graf wrote: >> >> On 28.03.2013, at 12:42, Fabien Chouteau wrote: >> >>> >>> While working on a patch to remove env->hreset_excp_prefix, I'm looking >>> at which instruction should be the fetched first at power-on. I'm lost >>> in all the PPC version and configuration, can anyone (Alex :) can help >>> me with this mess? >> >> Phew - I'd say just keep the targets you don't know exactly as they are :). >> That way you at least don't break anything that wasn't broken before. >> >> For the targets where you do know better (like 7x0), change its behavior to >> be correct according to the respective spec. >> > > Here's what I found in the UM of almost all the cores supported by QEMU: > > Every CPU should start at the hreset address (i.e. excp_prefix + 0x100). > > However, some cores don't have a hreset exception (4xx and Book E (e200, > e500)), those cores start at 0xFFFF_FFFC.
At least the G5 and I think also more recent POWER CPUs have either a small command stream or a full blown service processor that initialize initial CPU state like the PC. So there, the CPU starts at a board defined address. I don't think we need to worry too much about that for now though. Alex
