isa0 at pcib0

isa0 at pcib0

Post by Marc D Simps » Sat, 19 Jul 2003 15:24:17



Hey guys,

A quick question ... I've got the following output in dmesg:

isa0 at pcib0
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64
lpt0 at isa0 port 0x378-0x37b irq 7
[snip]
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
[snip]
wss2 at isapnp0 port 0x534/4,0x388/4,0x220/16 irq 5 drq 1,0
[snip]

--- my question being this; why is everything from my modem to my
sound card (which is built into my Intel SE440BX motherboard) running
on an isa channel; and additionally, that very first line suggests
that the isa channel, isa0, is running on top of, or being emulated
by, the first pci bus.

Perhaps I'm being a little dumb, but I can't quit eunderstand why on
my modern (ish) x86 (333 Celeron) most things are running on isa, when
PCI has long since surplanted it as the major bus technology.

Is this a case of emulation by NetBSD --- "isa0 at pcib0" --- or am I
being incredibly dopey?

appreciate the time,
cheers,
Marc

 
 
 

isa0 at pcib0

Post by Martijn van Buu » Sat, 19 Jul 2003 15:41:04


It occurred to me that Marc D Simpson wrote in comp.unix.bsd.netbsd.misc:

Quote:> --- my question being this; why is everything from my modem to my
> sound card (which is built into my Intel SE440BX motherboard) running
> on an isa channel;

Legacy I/O. And it *is* running on ISA.

Quote:> and additionally, that very first line suggests that the isa channel, isa0,
> is running on top of, or being emulated by, the first pci bus.

The ISA bus connects to an ISA-to-PCI-bridge, yes.

Quote:> Perhaps I'm being a little dumb, but I can't quit eunderstand why on
> my modern (ish) x86 (333 Celeron) most things are running on isa, when
> PCI has long since surplanted it as the major bus technology.

Backward compatibility, for instance, in combination with the fact that
there is absolutely no need to dedicate precious PCI nodes to it. A serial
or parallel port is not limited by the ISA architecture. Neither is a keyboard
controller, or a mouse port, or a simple soundcard.

--

         Geek code: G--  - Visit OuterSpace: mud.stack.nl 3333
  Research is what I'm doing when I don't know what I'm doing (W. von Braun)

 
 
 

isa0 at pcib0

Post by Marc D Simps » Sat, 19 Jul 2003 22:41:34


Martijn,

Your reply is much appreciated, and very informative ... thank you.

As you may have noted, my knowledge of modern PC architecture is
somewhat lacking, and hence your explanation, and the consequent
searching and reading than ensued on my end, have proved incredibly
beneficial.

cheers for the help,
regards,
Marc

[snip]

Quote:

> Legacy I/O. And it *is* running on ISA.

> > and additionally, that very first line suggests that the isa channel, isa0,
> > is running on top of, or being emulated by, the first pci bus.

> The ISA bus connects to an ISA-to-PCI-bridge, yes.

[snip]

> Backward compatibility, for instance, in combination with the fact that
> there is absolutely no need to dedicate precious PCI nodes to it. [...]

 
 
 

isa0 at pcib0

Post by Rene Schickbaue » Tue, 22 Jul 2003 06:04:10



>> and additionally, that very first line suggests that the isa channel,
>> isa0, is running on top of, or being emulated by, the first pci bus.

> The ISA bus connects to an ISA-to-PCI-bridge, yes.

So to say: Most of the On-Board-*is running ISA because it's *ing
cheap to recycle old 486-chips :-)

What i really hate on that computers: You *have* ISA but can't use
ISA-cards. Wouldn't even take more slots away: The old Alpha-stations do
have 3 ISA and 3 PCI-connectors - but only 3 slots at all at the same time
:-)

LLAP & LG
Rene

 
 
 

1. 4.1-RELEASE: isa0: too many dependent configs (8)

I just installed 4.1-RELEASE onto a SCSI drive.  Because it is for a
very busy machine (which was running 2.2.7), I actually put the (new)
drive in another computer to do the installation and update all the
user programs we need.  Then we put the disk into the real machine,
and (after a few glitches) got most everything working.

One thing that is NOT working, however, is the second SCSI board in
the target machine.  The one I did the installation on had only the
one scsi adapter, but the target machine has two, one PCI the other
ISA.  The PCI one works fine, but the ISA one (which has only a DAT
drive on it) does not.  I get error messages as follows on bootup:

...
Sep 21 12:39:16 chemsun /kernel: isa0: too many dependant configs (8)
...
Sep 21 12:39:16 chemsun /kernel: adv1: Invalid baseport of 0x340 specified.
        Nearest valid baseport is 0x330.  Failing probe.
Sep 21 12:39:16 chemsun /kernel: unknown0: <SCSI Controller> at port
        0x340-0x35f irq 11 on isa0
...

I suppose I may be able to change jumpers on the ISA scsi board, to
use lower address, but I am not clear why it is necessary, nor what
the first message means, and whether it has anything to do with the
problem.  Under 2.2.7, the bootup message was:

Sep 15 12:35:58 chemsun /kernel: aic0 at 0x340-0x35f irq 11 on isa

My main problem is that this is not a machine I can shut down easily
and experiment with; when I do shut it down I would like to be
confident that what I do will fix the problem.

Any advice or information would be welcome.

--

Director NMR Lab        612-626-0297
Chemistry Dept.         University of Minnesota

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