Subject: Re: UVM/PMAP Problem & IBM NS 1000
To: None <>
From: John Gordon <>
List: tech-kern
Date: 04/15/2003 02:27:31
Hello folks,

I discovered the problem I was having earlier, and I now I find it impossible
to believe that any of the PREP ports are working with the
netbsd-1-6-PATCH001-RC2 tag code...

The cause of the problem was that the USER_SR value had been changed from 13 to
12 as part of the switch to the newer PMAP module for the 6xx CPUs.
Unfortunately, that segment address happens to overlap with the PREP memory
mapped I/O address, which is mapped using a BAT register.

Since BATs take precedence over the PTEs, the copyout was being mapped using
the BAT translation to essentially nowhere (clearly this hardware doesn't have
a h/w bus error facility!). Moving the USER_SR value to 11, which is where it
seems to be located in the -current code, makes it work perfectly.

I now have a ramdisk version of NetBSD running on the IBM NS 1000 device :-)

All that remains is to add the CRC tool into the build process somewhere (at
the moment I am doing that manually on my Linux box using the Linux version of
the tool).

I might also look at the work necessary to make it work in -current, but I
think that doing this outside of the PREP framework, as a separate platform
based on powerpc might be better long term.


Boot Message:

Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002
    The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 1.6.1_RC2 (EMBEDDED) #95: Tue Apr 15 02:11:52 PDT 2003
Model: IBM 8362-XXX
total memory = 65536 KB
avail memory = 56088 KB
using 844 buffers containing 3376 KB of memory
mainbus0 (root)
cpu0 at mainbus0: 603ev (Revision 2.6), ID 0 (primary)
cpu0: HID0 90c000<DOZE,DPM,ICE,DCE>
pci0 at mainbus0 bus 0: indirect configuration space access
pci0: i/o space, memory space enabled
pchb0 at pci0 dev 0 function 0
pchb0: vendor 0x1014 product 0x0037 (rev. 0x02)
pcib0 at pci0 dev 1 function 0
pcib0: PIRQ[0-3] not used
pcib0: vendor 0x1014 product 0x000a (rev. 0x03)
pcn0 at pci0 dev 2 function 0: AMD PCnet-PCI Ethernet
pcn0: Am79c971 PCnet-FAST rev 5, Ethernet address ff:b9:ff:f9:7c:7f
pcn0: interrupting at irq 15
ukphy0 at pcn0 phy 0: Generic IEEE 802.3u media interface
ukphy0: OUI 0x00a0be, model 0x0002, rev. 3
ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
vendor 0x5333 product 0x8901 (VGA display, revision 0x14) at pci0 dev 4
function 0 not configured
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com0: console
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
biomask 0 netmask 8000 ttymask 8000

md0: internal 2048 KB image area
boot device: <unknown>
root on md0a dumps on md0b
WARNING: preposterous clock chip time
root file system type: ffs

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