[Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Ben Pfaff]

This is the minimal patch that, combined with my previous patch,
allows a Windows NT 4 guest to boot with qemu's PCI support
enabled.  It seems that WNT4 is pretty grumpy about the DSC
("device seek complete") bit in the status register.  If we don't
set it on WIN_SPECIFY, WNT4 times out and gives up on the device.

diff -u -p -u -r1.26 ide.c
--- hw/ide.c	25 Jun 2004 14:54:19 -0000	1.26
+++ hw/ide.c	14 Jul 2004 06:15:40 -0000
@@ -1477,7 +1477,7 @@ static void ide_ioport_write(void *opaqu
         case WIN_SPECIFY:
         case WIN_RECAL:
             s->error = 0;
-            s->status = READY_STAT;
+            s->status = READY_STAT | SEEK_STAT;
             ide_set_irq(s);
             break;
         case WIN_SETMULT:

-- 
Ben Pfaff 
email: blp@cs.stanford.edu
web: http://benpfaff.org

Re: [Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Johannes Schindelin]

Hi Ben,

great work! Out of curiosity: how did you manage to find out what is going
wrong? (may help others to debug similarly complicated situations...)

Ciao,
Dscho

Re: [Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Ben Pfaff]

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

> great work! Out of curiosity: how did you manage to find out what is going
> wrong? (may help others to debug similarly complicated situations...)

To tell that the lack of CMOS was a problem, I tried the WNT4
install under both Bochs (in which WNT4 worked) and qemu and set
up both to dump out IDE port reads and writes in the same trace
format.  Then I `diff'ed the outputs.  There were lots of
differences so I adjusted the qemu state machine until the traces
were bug-for-bug identical.  It still didn't work so I knew
something else had to be the problem, and eventually I thought of
the CMOS.

I did about the same thing for figuring out how to make PCI work.
I turned on lots of debug print statements, then ran installs
with PCI enabled and disabled, and looked at the `diff' between
the debug print outputs.  There was a particular point in the PCI
trace where the guest was sitting in a loop polling the IDE
status register until it timed out, so I figured that it was
looking for a bit that wasn't on.  Adding the "seek complete" bit
fixed it.
-- 
"...I've forgotten where I was going with this,
 but you can bet it was scathing."
--DesiredUsername

[Qemu-devel] Win98 network & cirrus logic success

[Johannes Schindelin]

Hi,

short warning at first: don't ping. It does not do what you think it does.
Try looking at a web page instead.

After long hours and nights, I finally got Win98 working as it should.
However, it was not easy: first of all, I forgot to update the rom images
in /usr/local/share/qemu. This resulted in several crashes. Even after
that, I had plenty of crashes, the network card would not be recognized,
and it was generally very frustrating. I then played with the device
manager and kept removing devices (especially that APM device...). A few
times Win98 then would "recognize" devices with very strange names (all
characters > 0x80 ASCII), which I removed at once. A few times the host
bridge was installed. At one time, the IDE controller was defunct, so
Win98 could not detect the cdrom. After that, however, things became much
more stable. Win98 recognized everything just fine. It forgot the HiColor
setting a couple of times, but then it worked. Without crashing.

Next came the network. I tried to ping, and it wouldn't. ipconfig showed
no 169.* rubbish, but the expected 10.* address. I now think the ping
fails, because the answer is not correctly routed back, being ICMP instead
of TCP. When I finally had that idea and just tried to surf to
www.google.de, it just worked...

In hindsight, I think it would have been easier to just reinstall
Windows98: The original installation was before cirrus logic and pci were
present in qemu.

Ciao,
Dscho

Re: [Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Hetz Ben Hamo]

On Wednesday 14 July 2004 09:18, Ben Pfaff wrote:
> This is the minimal patch that, combined with my previous patch,
> allows a Windows NT 4 guest to boot with qemu's PCI support
> enabled.  It seems that WNT4 is pretty grumpy about the DSC
> ("device seek complete") bit in the status register.  If we don't
> set it on WIN_SPECIFY, WNT4 times out and gives up on the device.

Fabrice, do you plan to commit Ben's patches soon, or should I put it on my 
web site for now?

Thanks,
Hetz

Re: [Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Fabrice Bellard]

Applied.

Fabrice.

Ben Pfaff wrote:
> This is the minimal patch that, combined with my previous patch,
> allows a Windows NT 4 guest to boot with qemu's PCI support
> enabled.  It seems that WNT4 is pretty grumpy about the DSC
> ("device seek complete") bit in the status register.  If we don't
> set it on WIN_SPECIFY, WNT4 times out and gives up on the device.
> 
> diff -u -p -u -r1.26 ide.c
> --- hw/ide.c	25 Jun 2004 14:54:19 -0000	1.26
> +++ hw/ide.c	14 Jul 2004 06:15:40 -0000
> @@ -1477,7 +1477,7 @@ static void ide_ioport_write(void *opaqu
>          case WIN_SPECIFY:
>          case WIN_RECAL:
>              s->error = 0;
> -            s->status = READY_STAT;
> +            s->status = READY_STAT | SEEK_STAT;
>              ide_set_irq(s);
>              break;
>          case WIN_SETMULT:
> 

Re: [Qemu-devel] [patch] make PCI work with Windows NT 4 guest

[Magnus Damm]

While at it, what about:

http://lists.gnu.org/archive/html/qemu-devel/2004-07/msg00574.html

/ magnus

On Sat, 2004-10-09 at 18:49, Fabrice Bellard wrote:
> Applied.
> 
> Fabrice.
> 
> Ben Pfaff wrote:
> > This is the minimal patch that, combined with my previous patch,
> > allows a Windows NT 4 guest to boot with qemu's PCI support
> > enabled.  It seems that WNT4 is pretty grumpy about the DSC
> > ("device seek complete") bit in the status register.  If we don't
> > set it on WIN_SPECIFY, WNT4 times out and gives up on the device.
> > 
> > diff -u -p -u -r1.26 ide.c
> > --- hw/ide.c	25 Jun 2004 14:54:19 -0000	1.26
> > +++ hw/ide.c	14 Jul 2004 06:15:40 -0000
> > @@ -1477,7 +1477,7 @@ static void ide_ioport_write(void *opaqu
> >          case WIN_SPECIFY:
> >          case WIN_RECAL:
> >              s->error = 0;
> > -            s->status = READY_STAT;
> > +            s->status = READY_STAT | SEEK_STAT;
> >              ide_set_irq(s);
> >              break;
> >          case WIN_SETMULT:
> > 
> 
> 
> 
> 
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