[9fans] plan 9 on qemu

[Russ Cox <russcox@gmail.com>]

I rebuilt the install floppy (it had been a year), so any
new hardware support should be present in it.  In particular,
it contains the vgadb entry for the QEMU vga card.

The CD-ROM is rebuilt every night so it was already up-to-date.

Jim and I looked at the QEMU disk issue today.  The problem
is that QEMU doesn't implement the (required) execute device
diagnostics command.  The following patch fixes QEMU.  I will
send it to the QEMU guys too.

*** hw/old.ide.c	Thu Dec 23 18:02:08 2004
--- hw/ide.c	Thu Dec 23 18:03:00 2004
***************
*** 1477,1482 ****
--- 1477,1489 ----
              }
              ide_set_irq(s);
              break;
+         case WIN_DIAGNOSE:
+             ide_set_signature(s);
+             s->status = READY_STAT;
+             /* 0x01: both devices passed or not present */
+             s->error = 0x01;
+             ide_set_irq(s);
+             break;
          case WIN_SPECIFY:
          case WIN_RECAL:
              s->error = 0;

Enjoy.
Russ