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

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

[Mark Jonckheere]

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

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

[Fabrice Bellard]

Mark Jonckheere wrote:
> ++++++++++++++++++++++++
> 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
> @@ -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;

This patch is not correct: it limits the memory to 16K, not 32K because 
the memory starts at a 16K offset. A possible solution could be to wrap
to 16K only if (tpsr << 8) >= 48K. Moreover, it should be done in the 
packet transmit code.

> 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.

OK for this one.

Fabrice.

[Qemu-devel] Re: [PATCH] ne2000 and Netware 3.11 (Revised patch)

[Mark Jonckheere]

Fabrice Bellard wrote:
> 
> This patch is not correct: it limits the memory to 16K, not 32K because 
> the memory starts at a 16K offset. A possible solution could be to wrap
> to 16K only if (tpsr << 8) >= 48K. Moreover, it should be done in the 
> packet transmit code.

The patch worked because standard drivers know that an original ne2000
card only has 16K RAM. I wonder if Netware works with a 32K ne2000-clone.

I include two possible revised patches:

The first one is just a more consistent rewrite of the previous patch:

++8<++cut+here++>8++
--- ne2000.c	Sun Oct  3 15:56:00 2004
+++ ne2000-p1.c	Fri Apr  8 15:05:52 2005
@@ -103,7 +103,7 @@
  #define ENTSR_CDH 0x40	/* The collision detect "heartbeat" signal was lost. */
  #define ENTSR_OWC 0x80  /* There was an out-of-window collision. */

-#define NE2000_PMEM_SIZE    (32*1024)
+#define NE2000_PMEM_SIZE    (16*1024)
  #define NE2000_PMEM_START   (16*1024)
  #define NE2000_PMEM_END     (NE2000_PMEM_SIZE+NE2000_PMEM_START)
  #define NE2000_MEM_SIZE     NE2000_PMEM_END
@@ -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 16K memory available, ignore bit 8 */
+            s->tpsr = val & 0x7f;
              break;
          case EN0_TCNTLO:
              s->tcnt = (s->tcnt & 0xff00) | val;
++8<++cut+here++>8++

in the second one the correction is in the packet transmit code as you asked

++8<++cut+here++>8++
--- ne2000.c	Sun Oct  3 15:56:00 2004
+++ ne2000-p2.c	Fri Apr  8 15:06:01 2005
@@ -247,6 +247,7 @@
  {
      NE2000State *s = opaque;
      int offset, page;
+    int index;

      addr &= 0xf;
  #ifdef DEBUG_NE2000
@@ -264,10 +265,15 @@
                  ne2000_update_irq(s);
              }
              if (val & E8390_TRANS) {
-                qemu_send_packet(s->nd, s->mem + (s->tpsr << 8), s->tcnt);
+                /* XXX: next 3 lines are a hack to make netware 3.11 work */
+                index = s->tpsr << 8;
+                if (index >= NE2000_PMEM_END)
+                    index -= NE2000_PMEM_SIZE;
+                qemu_send_packet(s->nd, s->mem + index, s->tcnt);
                  /* signal end of transfert */
                  s->tsr = ENTSR_PTX;
                  s->isr |= ENISR_TX;
+                s->cmd &= ~E8390_TRANS;
                  ne2000_update_irq(s);
              }
          }
++8<++cut+here++>8++

greetings
Mark.
-- 
:wq