Re: when and how to enable caches

[Frank Wille <frank%phoenix.owl.de@localhost>]

Tim Rightnour wrote:

>> [...] What I see there, with PMAPDEBUG=BOOT, is *very* strange: [...]
>> fff605e0: 20622d61 7661696c 5b305d20 73746172 b-avail[0] star
> 
> Is 0xfff anything a safe place? You have ram that far up?

Yes. It is hardware-mapped. The PPC board maps (mirrors) 512k of the normal
RAM to 0xfff00000, to have a place for the exception vectors.


> Does amgiappc have a bootloader, or does it somehow launch the kernel
> directly?

I wrote the bootloader myself, running under AmigaOS. The M68k loads the
kernel into memory and starts the PPC by copying a start-routine to
0xfff00000, then writes to a board-register to reset it.


> It might be worth trying to enable cache in the bootloader
> instead.

The bootloader is a 68k program (of course I'm flushing its caches before
giving control to the PPC). The PPC starts its life with locore.


-- 
    _  Frank Wille (frank%phoenix.owl.de@localhost)
 _ //  http://sun.hasenbraten.de/~frank/
 \X/   Phx @ #AmigaGer