[Qemu-devel] [PATCH] ne2000 and Netware 3.11

[Mark Jonckheere <mark.jonckheere@easynet.be>]

I installed an old Netware 3.11 distribution in a qemu virtual machine
and MSdos 5.0 and a Netware client in an other one.

The network connection was tested with VDE using following commands:

as user root:

    vde_switch -tap tap0 -hub -daemon
    chmod 766 /tmp/vde.ctl
    ethereal &

as non-privileged user:

    vdeqemu novell.img -localtime -isa &
    vdeqemu msdos5.img -localtime -isa -macaddr 52:54:00:22:44:66 &

Ethereal showed me that the IPX packets from Netware where malformed,
and after a lot of tracing and debugging I found out that the netware
ne2000 driver initializes the TPSR register with value 0xc0. This makes
the transmitter point to memory offset 48K where there is only memory
defined between offset 16K and 48K.

Since the TPSR register can address 64K memory and the NIC has only
32K "physical" memory available, the most logical solution is to
consider the most significant bit as a non-connected addressline and
make the memory adresses wrap around.

the following patch makes the ne2000 NIC work correctly under Netware 3.11

++++++++++++++++++++++++
diff -wurb qemu/hw/ne2000.c qemu-patched/hw/ne2000.c
--- qemu/hw/ne2000.c    Sun Oct  3 15:56:00 2004
+++ qemu-patched/hw/ne2000.c    Tue Mar 22 20:13:07 2005
@@ -268,6 +268,7 @@
                  /* signal end of transfert */
                  s->tsr = ENTSR_PTX;
                  s->isr |= ENISR_TX;
+                s->cmd &= ~E8390_TRANS;
                  ne2000_update_irq(s);
              }
          }
@@ -289,7 +290,8 @@
              ne2000_update_irq(s);
              break;
          case EN0_TPSR:
-            s->tpsr = val;
+            /* XXX: only 32K memory available, ignore bit 8 */
+            s->tpsr = val & 0x7f;
              break;
          case EN0_TCNTLO:
              s->tcnt = (s->tcnt & 0xff00) | val;
++++++++++++++++++++++++

Note:this patch also includes the patch I proposed on 24-12-2004
with title: "[PATCH] ne2000: Reset TXP bit after sending packet."
since it is also needed to make Netware recognise the ne2000 card.

see also:
    http://lists.gnu.org/archive/html/qemu-devel/2004-12/msg00292.html

groeten,
Mark.
-- 
:wq