From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Mon,  7 Apr 1997 08:24:26 -0500
From: Brian L. Stuart stuart@colossus.mathcs.rhodes.edu
Subject: Plan 9 on Sun IPC + cgthree?
Topicbox-Message-UUID: 5619e908-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19970407132426.DUQ5dO6z9R63Pd7Ejucj_rgf67Gtc-lLZF6s1_Bt4Rs@z>

>I found that although my cgthree is in a lower slot than the
>onboard bwtwo the kernel hardcodes bwtwo for SLC and IPC systems,
>rather than scanning the slots. Compiled a new kernel with quick
>hack: case IPC hardcode my cgthree instead. With this kernel the
>numbers go up to 7ec00 but otherwise no change.
>My first thought was that it was switching to the bwtwo after
>reaching the 7ea00, but the new kernel doesn't help. Any ideas
>where else to look?

I found exactly the same behavior with the original kernel,
but as it turned out, I did have a bwtwo only machine I
could try it on and it worked there.  The kernel hack I
did was to allow the IPC to be picked up by the same code
as the SPARC 2 and let the kernel figure it out.  It seems
to work fine.

In particular, I just commented out the case 0x52: label
in the switch statement and let the default: case pick it
up.  That has booted correctly on an IPC with a cgthree.

Hope this helps,
Brian L. Stuart
Math/CS Dept, Rhodes College, Memphis, TN
stuartb@acm.org
http://www.mathcs.rhodes.edu/~stuart/