Re: [PATCH 0/4] Atari kernel-in-FastRAM patches, take three

[schmitz <schmitz@biophys.uni-duesseldorf.de>]

Hi Geert,
> > > > do we know the size of the first memory chunk early enough in head.S?
> > > > Maybe it's time to increase INIT_MAPPED_SIZE at least in cases where
> > > > we know that there's more than 4 MB in the first memchunk ...
> > > >         
> > > How do you know?  You would have to reimplement the check paging_init
> > > does.
> > >       
> > I see - as a heuristic, we can probably assume that the first memchunk is
> > the relevant one, and especially in the case of FastRAM, also the larger
> > one.
> > Does this hold for Amiga/Mac/VME as well?
> >     
>
> People want to run the kernel in the fastest memory chunk, which is typically
> also the largest (slow Amiga mainboard memory may be 2 - 16 MiB for
> Linux-capable machines, accelerator memory may be larger).
>   

And the chunk the kernel runs from would always be the first chunk 
listed in bootinfo, since that's the one mapped at virtual address zero?

> Don't know about Mac, but I have some memories of interleaved banks
> and such...
>   

Not sure I've ever seen accelerators or memory upgrades on the Macs that 
I hacked on. 4 MB was sort of plenty in those days.

Cheers,

   Michael