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

Finn Thain
2014-04-04T06:09:07Z

On Thu, 3 Apr 2014, Scott Holder wrote:

> On 4/1/2014 8:23 AM, Finn Thain wrote:
>
> > It may be possible to boot Linux with MacOS running in 24-bit mode,
> > and ISTR that this leads to a large number of memory chunks. The
> > Penguin documentation says use 32-bit mode (which means installing
> > Mode32 if you have old MacOS and old ROMs). The only Mac I have here
> > is running MacOS 7.6 so I can't test 24-bit mode. You can see the
> > debug output from Penguin below.
>
> I happen to have my crazy PearPC/Mac OS X-booting LC475 still up and
> running with a 7.5.5 system folder on it. I rebooted it into 24-bit mode
> and loading Penguin does give a warning that 32-bit mode works better.
> Attempting to boot generates:
>
> *** Too many memory ranges!!!
> Error:
> *** setup_ram_mappings() failure - too many mappings

>From the Penguin source, MMU/MMU_V2.c, that means more than 32 chunks.

>
> I have a 64mb simm in this LC475; I tried popping it out (leaving me
> with 4mb) and it actually did attempt to unpack the kernel, but there's
> too little memory to do it. I have a bagful of smaller 72-pin simms
> kicking around somewhere; I'll have to dig it out of the closet and try
> it again.

You should be able to get Penguin to list the mappings even when it
doesn't have room to unpack a kernel.

But there's probably no need: it seems highly likely that you'd see
no 16 MB chunk on a 16 MB machine in 24-bit mode.

Finn