Improved MAC address handling for onboard Ethernet

First three bytes are ST OUI prefix, but with LAA bit set.
Last three bytes from a CRC32 hash of the 96 bit chip UID.

Optional new setting ($535) for overriding address.

LWIP/Target/ethernetif.c

@@ -33,7 +33,7 @@
 
 /* Within 'USER CODE' section, code will be kept by default at each generation */
 /* USER CODE BEGIN 0 */
-
+#include "networking/networking.h"
 /* USER CODE END 0 */
 
 /* Private define ------------------------------------------------------------*/
@@ -161,7 +161,7 @@ static void low_level_init(struct netif *netif)
   HAL_StatusTypeDef hal_eth_init_status = HAL_OK;
   /* Start ETH HAL Init */
 
-   uint8_t MACAddr[6] ;
+  uint8_t MACAddr[6] ;
   heth.Instance = ETH;
   MACAddr[0] = 0x00;
   MACAddr[1] = 0x80;
@@ -177,6 +177,11 @@ static void low_level_init(struct netif *netif)
 
   /* USER CODE BEGIN MACADDRESS */
 
+  uint8_t mac[6];
+
+  if(bmac_eth_get(mac))
+      heth.Init.MACAddr = &mac[0];
+
   /* USER CODE END MACADDRESS */
 
   hal_eth_init_status = HAL_ETH_Init(&heth);

Src/driver.c

@@ -1848,6 +1848,60 @@ void setPeriphPinDescription (const pin_function_t function, const pin_group_t g
     } while(ppin);
 }
 
+
+#if ETHERNET_ENABLE
+
+uint32_t crc32_bitwise(const void* data, size_t length)
+{
+  const uint32_t polynomial = 0xEDB88320;
+  uint32_t crc = 0xFFFFFFFF;
+  unsigned char* current = (unsigned char*) data;
+  while (length--)
+  {
+    crc ^= *current++;
+    for (unsigned int j = 0; j < 8; j++)
+      if (crc & 1)
+        crc = (crc >> 1) ^ polynomial;
+      else
+        crc =  crc >> 1;
+  }
+  return ~crc;
+}
+
+bool bmac_eth_get (uint8_t mac[6])
+{
+#if defined(_WIZCHIP_)
+    // WizNet OUI prefix
+    mac[0] = 0x00;
+    mac[1] = 0x08;
+    mac[2] = 0xDC;
+#else
+    // ST OUI prefix
+    mac[0] = 0x00;
+    mac[1] = 0x80;
+    mac[2] = 0xE1;
+#endif
+
+    // Set LAA bit
+    mac[0] |= 0x02;
+
+    // Get 96 bit unique device identifier
+    uint32_t uid[3];
+    uid[0] = HAL_GetUIDw0();
+    uid[1] = HAL_GetUIDw1();
+    uid[2] = HAL_GetUIDw2();
+
+    // Generate 32bit CRC from 96 bit UID
+    uint32_t crc = crc32_bitwise(uid, 12);
+
+    // Copy first 24bits of the CRC into the MAC address
+    memcpy(&mac[3], &crc, 3);
+
+    return true;
+}
+
+#endif // ETHERNET_ENABLE
+
 // Initializes MCU peripherals for Grbl use
 static bool driver_setup (settings_t *settings)
 {
@@ -2112,7 +2166,7 @@ bool driver_init (void)
     hal.info = "STM32H743";
 #endif
 
-    hal.driver_version = "240522";
+    hal.driver_version = "240624";
     hal.driver_url = "https://github.com/dresco/STM32H7xx";
 #ifdef BOARD_NAME
     hal.board = BOARD_NAME;

Src/enet.c

@@ -3,20 +3,20 @@
 
   Part of grblHAL
 
-  Copyright (c) 2021-2023 Terje Io
+  Copyright (c) 2021-2024 Terje Io
 
-  Grbl is free software: you can redistribute it and/or modify
+  grblHAL is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
-  Grbl is distributed in the hope that it will be useful,
+  grblHAL is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
-  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
+  along with grblHAL. If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "driver.h"
@@ -93,8 +93,15 @@ static void report_options (bool newopt)
             hal.stream.write(",SSDP");
 #endif
     } else {
+
+        network_info_t *network = networking_get_info();
+
+        hal.stream.write("[MAC:");
+        hal.stream.write(network->mac);
+        hal.stream.write("]" ASCII_EOL);
+
         hal.stream.write("[IP:");
-        hal.stream.write(IPAddress);
+        hal.stream.write(network->status.ip);
         hal.stream.write("]" ASCII_EOL);
 
         if(active_stream == StreamType_Telnet || active_stream == StreamType_WebSocket) {
@@ -141,7 +148,7 @@ network_info_t *networking_get_info (void)
             ip4addr_ntoa_r(netif_ip_netmask4(netif), info.status.mask, IP4ADDR_STRLEN_MAX);
         }
 
-        sprintf(info.mac, MAC_FORMAT_STRING, netif->hwaddr[0], netif->hwaddr[1], netif->hwaddr[2], netif->hwaddr[3], netif->hwaddr[4], netif->hwaddr[5]);
+        strcpy(info.mac, networking_mac_to_string(netif->hwaddr));
     }
 
 #if MQTT_ENABLE
@@ -381,6 +388,18 @@ static char *ethernet_get_ip (setting_id_t setting);
 static status_code_t ethernet_set_services (setting_id_t setting, uint_fast16_t int_value);
 static uint32_t ethernet_get_services (setting_id_t id);
 
+#ifdef HAS_MAC_SETTING
+static status_code_t ethernet_set_mac (setting_id_t setting, char *value)
+{
+	return networking_string_to_mac(value, ethernet.mac) ? Status_OK : Status_InvalidStatement;
+}
+
+static char *ethernet_get_mac (setting_id_t setting)
+{
+    return networking_mac_to_string(ethernet.mac);
+}
+#endif
+
 static const setting_group_detail_t ethernet_groups [] = {
     { Group_Root, Group_Networking, "Networking" }
 };
@@ -392,6 +411,9 @@ static const setting_detail_t ethernet_settings[] = {
     { Setting_IpAddress, Group_Networking, "IP Address", NULL, Format_IPv4, NULL, NULL, NULL, Setting_NonCoreFn, ethernet_set_ip, ethernet_get_ip, NULL, { .reboot_required = On } },
     { Setting_Gateway, Group_Networking, "Gateway", NULL, Format_IPv4, NULL, NULL, NULL, Setting_NonCoreFn, ethernet_set_ip, ethernet_get_ip, NULL, { .reboot_required = On } },
     { Setting_NetMask, Group_Networking, "Netmask", NULL, Format_IPv4, NULL, NULL, NULL, Setting_NonCoreFn, ethernet_set_ip, ethernet_get_ip, NULL, { .reboot_required = On } },
+#ifdef HAS_MAC_SETTING
+    { Setting_NetworkMAC, Group_Networking, "MAC Address", NULL , Format_String, "x(17)", "17", "17", Setting_NonCoreFn, ethernet_set_mac, ethernet_get_mac, NULL, { .allow_null = On, .reboot_required = On } },
+#endif
     { Setting_TelnetPort, Group_Networking, "Telnet port", NULL, Format_Int16, "####0", "1", "65535", Setting_NonCore, &ethernet.telnet_port, NULL, NULL, { .reboot_required = On } },
 #if FTP_ENABLE
     { Setting_FtpPort, Group_Networking, "FTP port", NULL, Format_Int16, "####0", "1", "65535", Setting_NonCore, &ethernet.ftp_port, NULL, NULL, { .reboot_required = On } },
@@ -417,6 +439,9 @@ static const setting_descr_t ethernet_settings_descr[] = {
     { Setting_IpAddress, "Static IP address." },
     { Setting_Gateway, "Static gateway address." },
     { Setting_NetMask, "Static netmask." },
+#ifdef HAS_MAC_SETTING
+    { Setting_NetworkMAC, "Optional MAC address. Tip: get from an unused device, e.g an old router." },
+#endif
     { Setting_TelnetPort, "(Raw) Telnet port number listening for incoming connections." },
 #if FTP_ENABLE
     { Setting_FtpPort, "FTP port number listening for incoming connections." },
@@ -561,6 +586,10 @@ void ethernet_settings_restore (void)
         set_addr(ethernet.mask, &addr);
 #endif
 
+#ifdef HAS_MAC_SETTING
+    bmac_eth_get(ethernet.mac);
+#endif
+
     ethernet.ftp_port = NETWORK_FTP_PORT;
     ethernet.telnet_port = NETWORK_TELNET_PORT;
     ethernet.http_port = NETWORK_HTTP_PORT;