Re: MMU questions?

From: Doug Little <doug_at_innerworkings.co.uk>
Date: Mon, 8 Jun 1998 09:34:02 +0100

>But the PMMU is already in use on the AB, to remap/write-protect the
>RAM-image of the patched ROM, and to remap the fastRAM. Won't this
>crash with other PMMU-stuff?


Yes, but only if the kernel is loaded into remapped-ram (FastRAM), otherwise
the AB hacked TOS will suddenly vanish and be replaced with old TOS until
Linux finishes setting itself up. No major problem there, so long as the
caches
are off while loading from SCSI in the meantime.

However, if FastRAM is enabled under TOS, and Linux is loaded into FastRAM
then the first thing that happens when Linux fiddles with the PMMU is this:
It will
completely knacker itself because the code being executed will teleport to
another
location as soon as the PMMU gets turned off/changed. It will literally pull
the rug
from under its own feet.

Doug.
Received on ma. juni 08 1998 - 18:34:00 CEST

This archive was generated by hypermail 2.3.0 : ti. nov. 03 2015 - 20:07:54 CET