TMXR, PDP11, PDP10, VAX: Add DDCMP sync framer support

This adds support for the "framer" device, which is a USB-connected device built around a Raspberry Pico that connects to a synchronous line, either RS-232 or DEC "integral modem" coax connection. It implements the framing portion of DDCMP: clock recovery for the integral modem case, byte sync, and DDCMP frame handling including CRC. The actual DDCMP protocol state machine, with its handling of sequencing, timeout and retransmit, etc. is left to the host software. All the design files for the framer may be found at https://github.com/pkoning2/ddcmp . This commit adds code to drive the framer from the TMXR library, allowing it to be used either from simulated DMC-11 or simulated DUP-11 devices. Both have been tested, using RSTS/E, RSX-11/M+, and TOPS-20. Fixed the one-digit limit on eth<n> device names, the limit is now 2.
2026-01-25 11:55:43 +00:00 · 2022-01-08 14:24:42 -08:00
parent 030a47bdb4
commit 5cd1e8b7ac
9 changed files with 601 additions and 86 deletions
--- a/sim_ether.c
+++ b/sim_ether.c
@@ -383,6 +383,9 @@

 /* Internal routine - forward declaration */
 static int _eth_get_system_id (char *buf, size_t buf_size);
+static void eth_get_nic_hw_addr(ETH_DEV* dev, const char *devname, int set_on);
+
+static const unsigned char framer_oui[3] = { 0xaa, 0x00, 0x03 };

 /*============================================================================*/
 /*                  OS-independant ethernet routines                          */
@@ -780,13 +783,11 @@ return eth_show (st, uptr, val, NULL);
 }

 #if defined (USE_NETWORK) || defined (USE_SHARED)
-/* Internal routine - forward declaration */
-static int _eth_devices (int max, ETH_LIST* dev);   /* get ethernet devices on host */

 static const char* _eth_getname(int number, char* name, char *desc)
 {
  ETH_LIST  list[ETH_MAX_DEVICE];
-  int count = _eth_devices(ETH_MAX_DEVICE, list);
+  int count = eth_devices(ETH_MAX_DEVICE, list, FALSE);

  if ((number < 0) || (count <= number))
      return NULL;
@@ -803,7 +804,7 @@ static const char* _eth_getname(int number, char* name, char *desc)
 const char* eth_getname_bydesc(const char* desc, char* name, char *ndesc)
 {
  ETH_LIST  list[ETH_MAX_DEVICE];
-  int count = _eth_devices(ETH_MAX_DEVICE, list);
+  int count = eth_devices(ETH_MAX_DEVICE, list, FALSE);
  int i;
  size_t j=strlen(desc);

@@ -829,7 +830,7 @@ const char* eth_getname_bydesc(const char* desc, char* name, char *ndesc)
 char* eth_getname_byname(const char* name, char* temp, char *desc)
 {
  ETH_LIST  list[ETH_MAX_DEVICE];
-  int count = _eth_devices(ETH_MAX_DEVICE, list);
+  int count = eth_devices(ETH_MAX_DEVICE, list, FALSE);
  size_t n;
  int i, found;

@@ -849,7 +850,7 @@ char* eth_getname_byname(const char* name, char* temp, char *desc)
 char* eth_getdesc_byname(char* name, char* temp)
 {
  ETH_LIST  list[ETH_MAX_DEVICE];
-  int count = _eth_devices(ETH_MAX_DEVICE, list);
+  int count = eth_devices(ETH_MAX_DEVICE, list, FALSE);
  size_t n;
  int i, found;

@@ -894,7 +895,7 @@ t_stat eth_show (FILE* st, UNIT* uptr, int32 val, CONST void* desc)
  ETH_LIST  list[ETH_MAX_DEVICE];
  int number;

-  number = _eth_devices(ETH_MAX_DEVICE, list);
+  number = eth_devices(ETH_MAX_DEVICE, list, FALSE);
  fprintf(st, "ETH devices:\n");
  if (number == -1)
    fprintf(st, "  network support not available in simulator\n");
@@ -965,6 +966,8 @@ t_stat eth_filter_hash (ETH_DEV* dev, int addr_count, ETH_MAC* const addresses,
  {return SCPE_NOFNC;}
 const char *eth_version (void)
  {return NULL;}
+int eth_devices(int max, ETH_LIST* list, ETH_BOOL framers)
+  {return 0;}
 void eth_show_dev (FILE* st, ETH_DEV* dev)
  {}
 t_stat eth_show (FILE* st, UNIT* uptr, int32 val, CONST void* desc)
@@ -1112,13 +1115,14 @@ for (i=0; i<used; i++) {
 return used;
 }

-static int _eth_devices(int max, ETH_LIST* list)
+int eth_devices(int max, ETH_LIST* list, ETH_BOOL framers)
 {
 int used = 0;
 char errbuf[PCAP_ERRBUF_SIZE] = "";
 #ifndef DONT_USE_PCAP_FINDALLDEVS
 pcap_if_t* alldevs;
 pcap_if_t* dev;
+ETH_DEV edev;

 memset(list, 0, max*sizeof(*list));
 errbuf[0] = '\0';
@@ -1129,7 +1133,11 @@ if (pcap_findalldevs(&alldevs, errbuf) == -1) {
  }
 else {
  /* copy device list into the passed structure */
-  for (used=0, dev=alldevs; dev && (used < max); dev=dev->next, ++used) {
+  for (used=0, dev=alldevs; dev && (used < max); dev=dev->next) {
+    edev.eth_api = ETH_API_PCAP;
+    eth_get_nic_hw_addr (&edev, dev->name, 0);
+    if ((memcmp (edev.host_nic_phy_hw_addr, framer_oui, 3) == 0) != framers)
+      continue;
    if ((dev->flags & PCAP_IF_LOOPBACK) || (!strcmp("any", dev->name)))
      continue;
    strlcpy(list[used].name, dev->name, sizeof(list[used].name));
@@ -1137,6 +1145,7 @@ else {
      strlcpy(list[used].desc, dev->description, sizeof(list[used].desc));
    else
      strlcpy(list[used].desc, "No description available", sizeof(list[used].desc));
+    ++used;
    }

  /* free device list */
@@ -1152,6 +1161,9 @@ if ((used == 0) && (errbuf[0])) {
    sim_printf ("Eth: pcap_findalldevs warning: %s\n", errbuf);
    }

+if (framers)
+    return used;    /* don't add pseudo-ethernet devices */
+
 #ifdef HAVE_TAP_NETWORK
 if (used < max) {
 #if defined(__OpenBSD__)
@@ -1736,7 +1748,7 @@ static int pcap_mac_if_vms(const char *AdapterName, unsigned char MACAddress[6])
 }
 #endif /* defined (__VMS) && !defined(__VAX) */

-static void eth_get_nic_hw_addr(ETH_DEV* dev, const char *devname)
+static void eth_get_nic_hw_addr(ETH_DEV* dev, const char *devname, int set_on)
 {
  memset(&dev->host_nic_phy_hw_addr, 0, sizeof(dev->host_nic_phy_hw_addr));
  dev->have_host_nic_phy_addr = 0;
@@ -1766,13 +1778,15 @@ static void eth_get_nic_hw_addr(ETH_DEV* dev, const char *devname)
        NULL};

    memset(command, 0, sizeof(command));
-    /* try to force an otherwise unused interface to be turned on */
-    for (i=0; turnon[i]; ++i) {
-      snprintf(command, sizeof(command), turnon[i], (int)(sizeof(command) - (2 + strlen(patterns[i]))), devname);
-      get_glyph_nc (command, tool, 0);
-      if (sim_get_tool_path (tool)[0]) {
-        if (NULL != (f = popen(command, "r")))
-          pclose(f);
+    if (set_on) {
+      /* try to force an otherwise unused interface to be turned on */
+      for (i=0; turnon[i]; ++i) {
+        snprintf(command, sizeof(command), turnon[i], (int)(sizeof(command) - (2 + strlen(patterns[i]))), devname);
+        get_glyph_nc (command, tool, 0);
+        if (sim_get_tool_path (tool)[0]) {
+          if (NULL != (f = popen(command, "r")))
+            pclose(f);
+          }
        }
      }
    for (i=0; patterns[i] && (0 == dev->have_host_nic_phy_addr); ++i) {
@@ -2500,12 +2514,13 @@ if (bufsz < ETH_MAX_JUMBO_FRAME)
 /* initialize device */
 eth_zero(dev);

-/* translate name of type "ethX" to real device name */
-if ((strlen(name) == 4)
+/* translate name of type "eth<num>" to real device name */
+if ((strlen(name) == 4 || strlen(name) == 5)
    && (tolower(name[0]) == 'e')
    && (tolower(name[1]) == 't')
    && (tolower(name[2]) == 'h')
    && isdigit(name[3])
+    && (strlen(name) == 4 || isdigit(name[4]))
   ) {
  num = atoi(&name[3]);
  savname = _eth_getname(num, temp, desc);
@@ -2545,7 +2560,7 @@ if (!strcmp (desc, "No description available"))
 sim_messagef (SCPE_OK, "Eth: opened OS device %s%s%s\n", savname, desc[0] ? " - " : "", desc);

 /* get the NIC's hardware MAC address */
-eth_get_nic_hw_addr(dev, savname);
+eth_get_nic_hw_addr(dev, savname, 1);

 /* save name of device */
 dev->name = (char *)malloc(strlen(savname)+1);
@@ -4368,7 +4383,7 @@ int bpf_compile_skip_count = 0;


 memset (&eth_tst, 0, sizeof(eth_tst));
-eth_device_count = _eth_devices(ETH_MAX_DEVICE, eth_list);
+eth_device_count = eth_devices(ETH_MAX_DEVICE, eth_list, FALSE);
 eth_opened = 0;
 for (eth_num=0; eth_num<eth_device_count; eth_num++) {
  char eth_name[32];