PDP11, VAX: Use generated unique default MAC addresses for Ethernet devices

PDP11/pdp11_xq.c

@@ -2538,6 +2538,12 @@ t_stat xq_reset(DEVICE* dptr)
 
   sim_debug(DBG_TRC, xq->dev, "xq_reset()\n");
 
+  /* One time only initializations */
+  if (!xq->var->initialized) {
+    xq->var->initialized = TRUE;
+    /* Set an initial MAC address in the DEC range */
+    xq_setmac (dptr->units, 0, "08:00:2B:00:00:00/24", NULL);
+    }
   /* calculate MAC checksum */
   xq_make_checksum(xq);
 
@@ -3171,8 +3177,8 @@ const char helpString[] =
     " A Valid MAC address is comprised of 6 pairs of hex digits delimited by\n"
     " dashes, colons or period characters.\n"
     "\n"
-    " The default MAC address for the XQ device is 08-00-2B-AA-BB-CC.  The\n"
+    " The default MAC address for the %D device is set to a value in the range\n"
-    " default MAC address for the XQB device is 08-00-2B-BB-CC-DD.\n"
+    " from 08-00-2B-00-00-00 thru 08-00-2B-FF-FF-FF.\n"
     "\n"
     " The SET MAC command must be done before the %D device is attached to a\n"
     " network.\n"

PDP11/pdp11_xq.h

@@ -312,6 +312,7 @@ struct xq_device {
   ETH_QUE           ReadQ;
   int32             idtmr;                              /* countdown for ID Timer */
   uint32            must_poll;                          /* receiver must poll instead of counting on asynch polls */
+  t_bool            initialized;                        /* flag for one time initializations */
 };
 
 struct xq_controller {

PDP11/pdp11_xu.c

@@ -849,6 +849,12 @@ t_stat xu_reset(DEVICE* dptr)
   CTLR* xu = xu_dev2ctlr(dptr);
 
   sim_debug(DBG_TRC, xu->dev, "xu_reset()\n");
+  /* One time only initializations */
+  if (!xu->var->initialized) {
+    xu->var->initialized = TRUE;
+    /* Set an initial MAC address in the DEC range */
+    xu_setmac (dptr->units, 0, "08:00:2B:00:00:00/24", NULL);
+    }
   /* init read queue (first time only) */
   status = ethq_init (&xu->var->ReadQ, XU_QUE_MAX);
   if (status != SCPE_OK)
@@ -1903,9 +1909,10 @@ fprint_set_help (st, dptr);
 fprintf (st, "\nConfigured options and controller state can be displayed with:\n\n");
 fprint_show_help (st, dptr);
 fprintf (st, "\nMAC address octets must be delimited by dashes, colons or periods.\n");
-fprintf (st, "The controller defaults to 08-00-2B-CC-DD-EE, which should be sufficient if\n");
+fprintf (st, "The controller defaults to a relatively unique MAC address in the range\n");
-fprintf (st, "there is only one SIMH DEUNA/DELUA controller on your LAN.  Two cards with the\n");
+fprintf (st, "08-00-2B-00-00-00 thru 08-00-2B-FF-FF-FF, which should be sufficient\n");
-fprintf (st, "same MAC address will see each other's packets, resulting in a serious mess.\n\n");
+fprintf (st, "for most network environments.  If desired, the simulated MAC address\n");
+fprintf (st, "can be directly set.\n");
 fprintf (st, "To access the network, the simulated Ethernet controller must be attached to a\n");
 fprintf (st, "real Ethernet interface.\n\n");
 eth_attach_help(st, dptr, uptr, flag, cptr);

PDP11/pdp11_xu.h

@@ -159,6 +159,7 @@ struct xu_device {
   uint16          udb[UDBSIZE];                         /* copy of Unibus Data Block */
   uint16          rxhdr[4];                             /* content of RX ring entry, during wait */
   uint16          txhdr[4];                             /* content of TX ring entry, during xmit */
+  t_bool          initialized;                          /* flag for one time initializations */
 };
 
 struct xu_controller {