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Re: Buying RAM expansion from project money



On Sun, Nov 3, 2013 at 8:20 AM, Michael Schmitz
<schmitz@biophys.uni-duesseldorf.de> wrote:
>> As I understood, the approval of approx. 500.- Euro to buy RAM expansions
>> for our buildds is given. Regarding to Adrian the DPL asked for a quote to
>> issue the money. So, the question is: how to proceed?
>>
>> The current situation:
>> We currently have 6 Amigas that have ZorroIII slots, namely: crest, elgar,
>> kullervo, arrakis, spice, vivaldi. Elgar and crest are remodded Desktop
>> Amigas built into Tower cases. That might work, but is not guaranteed. Would
>> both be brought back into original Desktop cases with genuine riser cards,
>> both ought to work fine as well.
>> Another "problem" is the kernel lacking SPARSEMEM support. There was some
>> discussion on this mailing list some weeks ago about this and additionally I
>> asked Geert in private what needs to be done to get this into the kernel. He
>> said it would probably mean a week of full time work when doing this on
>> Aranym, more when doing it on real hardware, but it is doable and most
>> likely needed to keep Debian on m68k alive.
>
>
> There's no reason why the sparsemem work has to be done on real hardware, is
> there?

Indeed. In private, I said:

"BTW, testing is not such a big issue: that can be done on ARAnyM as well.
E.g. for a virtual Atari with 256 MiB of FastRAM, you can hardcode it in
arch/m68k/kernel/setup_mm.c to have two chunks:
  - The first one being the last 128 MiB of FastRAM,
  - The second one being the first 127 MiB of FastRAM.
If that works, it should work on Amiga, too (hmm, fingers crossed)."

> What precisely is the memory layout when including the bigmem chunk?

A3000/4000 motherboard RAM: 0x07000000-0x07ffffff (max. 16 MiB,
    counting down from 0x08000000).
Zorro III memory: 0x40000000 (I think, I couldn't find ShowConfig output with
    a BigRamPlus)
CPU accelerator: depends on the board, e.g. 0x2000000 (?)

(slow) 16-bit Zorro II memory: 0x00200000-0x009fffff (if any)

Does BigRamPlus support RMW bus cycles? That's needed to use it as generic
RAM, as the MMU uses RMW bus cycles to update the page tables.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds


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