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Remove paragraph describing problem with initialising VMEbus RAM cards' 

parity bits. Initialisation now handled during kernel startup.
This commit is contained in:
scw 1997-11-01 19:18:39 +00:00
parent db674c76eb
commit d0d3cc7965
1 changed files with 1 additions and 15 deletions
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16
sys/arch/mvme68k/README.VMEbus-RAM
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@ -1,4 +1,4 @@
$NetBSD: README.VMEbus-RAM,v 1.1 1997/10/12 15:45:12 scw Exp $
$NetBSD: README.VMEbus-RAM,v 1.2 1997/11/01 19:18:39 scw Exp $
NetBSD/mvme68k port: VMEbus RAM card configuration
@ -62,20 +62,6 @@ onboard RAM and will not attempt to use any VMEbus RAM.
Some extra notes on VMEbus RAM cards
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Most VMEbus RAM cards support parity checking in some form or another.
This can cause problems with the kernel. It's fairly normal for a card
to only initialise the parity bit on write accesses. This means that
the card can generate lots of parity errors following power-up. What's
happening is that NetBSD doesn't zero the RAM's contents on boot-up
so there's stale (and probably incorrect) parity data in the card.
If this happens with your card, try block-filling the card with zero
from the 147Bug> prompt (see the 'BF' command) before booting NetBSD.
If that cures the problem, see if there's a jumper on the RAM card to
disable parity checking. If not, you might have no choice but to block-
fill the memory following a power-up.
So... You've got your nice shiny VMEbus RAM card up and running with
NetBSD, and you're wondering why your system runs slower than it did
with less RAM!