Re: What to do with slow Chip/ST RAM

["David Brownlee" <abs%absd.org@localhost>]

From:  <mlelstv%serpens.de@localhost>

> 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.

So the simplest way to have some ordering would be to assign priorities to each 
memory segment passed by the bootloader - does it pass it in fastest first?

Are there specific ranges known to be slow/fast ram which would help to 
adjust/merge the list?

> 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.

So would that memory be used by anything (devices etc), if not its a perfect 
candidate to be exposed as altmem... What happens to such memory now?