[OpenBIOS] [Qemu-ppc] Running client with MMU off

Alexander Graf agraf at suse.de
Thu Jun 26 13:23:58 CEST 2014


On 26.06.14 13:20, BALATON Zoltan wrote:
> On Thu, 26 Jun 2014, Alexander Graf wrote:
>> You could enable write protection on the first page before you enter 
>> the payload. Then you could unprotect it and disable interrupts as 
>> soon as someone wrote to it. I guess that'd be a pretty solid hack.
>
> Good idea, I'll look into this. But 0x00-0xff is reserved for 
> operating system use and MorphOS does write to 0x80 before touching 
> the vectors (that's why I can't just check from the DSI handler). Can 
> I selectively enable writes on a write protected page? (I'll need to 
> read about it some more.)

Not easily. You could emulate the 0x80 write maybe. Is it too early if 
you just disable DR/IR on the 0x80 touch? I don't think any other OS 
really accesses these ranges, but only time will tell ;).


Alex




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