Re: What to do with slow Chip/ST RAM

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

On Fri, Mar 13, 2009 at 06:53:07AM +0000, Michael van Elst wrote:
> abs%NetBSD.org@localhost (David Brownlee) writes:
> 
> >     So would this grouping make sense?
> 
> >     - 32bit "local" RAM on accelerator board (fastest)
> >     - 32bit "local" RAM on motherboard (next fastest)
> >     - Ranger memory/Zorro-II RAM/16bit RAM (slow)
> 
> >     - 32bit Chip RAM / 16bit Chip ram (not used for running programs)
> 
> Yes. And now for the tricky part to find out which is which.
> 
> If you forget about the 'grouping' you can just rely on the sorting
> of AmigaOS, the bootloader will pass the sorted list of memory
> regions. On some systems you will see multiple areas of the same type
> if e.g. there are several Zorro-II memory boards that cannot
> be coalesced into a single region.
> 
> There is one caveat, you cannot easily distinguish non-Chip RAM
> and Ranger memory. Both are presented as 'Fast RAM' and may
> use the same address space, non-Chip RAM however should not
> be used. The easiest solution is to forget about both by
> filtering out any memory region between 0x00A00000 and 0x00FFFFFF.

Uhm... what's exactly the purpose, again? If it is for prioritized
used of main system RAM, I think ZII RAM (at least) isn't accessible
to (at least some of) the SCSI DMA drivers.

Regards,
        -is