Re: proposal: millicode

[Ignatios Souvatzis <is%netbsd.org@localhost>]

On Sat, Jan 19, 2008 at 06:27:49PM +0100, Frank Wille wrote:
> Ignatios Souvatzis wrote:
> 
> > On Sat, Jan 19, 2008 at 09:02:33AM -0700, Tim Rightnour wrote:
> >> 
> >> On 19-Jan-2008 Ignatios Souvatzis wrote:
> >> Because at that address there is only Slooooooooooow RAM. You don't want
> >> to use it for anything else but DMA buffers for the audio device, the
> >> built-in graphics, and the built-in floppy, that are connected to it.
> >> 
> >> Where is that ram range on amigappc?  How far up does it extend?
> 
> The slow RAM (called "Chip-RAM") is from 0 to 0x1fffff (2MB). After that we
> have a gap, followed by memory-mapped I/O and the ROM. All below 0x01000000.
> 
> 
> > THose are Amiga 3000 and Amiga 4000 machines with on-mainboard fast
> > ram from 0x7000 0000 to 0x7fff ffff (max) and CPUboard RAM from
> > 0x8000 0000 up, where the last 512 kBytes are also (or instead -
> > I'm not sure) accessible at 0xFsomething, so you can put PPC trap
> > vectors there.
> 
> Although 256MB onboard RAM would be nice, it is only 16MB from 0x07000000 to
> 0x07ffffff. And a maximum of 128MB on the (PPC) CPU board at 0x08000000.
> 
> 
> > There are alos Amiga 1200 ppc boards, that have the RAM somewhere 
> > else.
> > 
> > Frank will know the exact numbers by heart, I guess ;-)
> 
> Not really. I never owned an A1200, but I heard there are CPU board revisions
> with different locations, mostly in the 0x60000000 area.
> 
> Of course, all that is not really important when regarding the current state
> of the port. But, when possible, Tim may want to keep it in mind.

My idea "back then" was to write a small relocator, which relocates the kernel
addresses at startup. Didn't I publish a prototype on port-amigappc?

        -is
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