drivers/cyw43: Allow configuring the netif/mDNS hostname.

Allow boards to configure/override the default hostname used for netif and
mDNS.

drivers/cyw43/cyw43.h

@@ -47,6 +47,14 @@
 #define CYW43_LINK_NONET        (-2)
 #define CYW43_LINK_BADAUTH      (-3)
 
+#ifndef MICROPY_BOARD_HOSTNAME
+#define MICROPY_BOARD_HOSTNAME  "PYBD"
+#endif
+
+#ifndef MICROPY_BOARD_HOSTNAME_LENGTH
+#define MICROPY_BOARD_HOSTNAME_LENGTH 16
+#endif
+
 typedef struct _cyw43_t {
     cyw43_ll_t cyw43_ll;
 
@@ -76,6 +84,7 @@ typedef struct _cyw43_t {
     struct netif netif[2];
     struct dhcp dhcp_client;
     dhcp_server_t dhcp_server;
+    char hostname[MICROPY_BOARD_HOSTNAME_LENGTH];
 } cyw43_t;
 
 extern cyw43_t cyw43_state;

drivers/cyw43/cyw43_ctrl.c

@@ -101,6 +101,8 @@ void cyw43_init(cyw43_t *self) {
     self->ap_channel = 3;
     self->ap_ssid_len = 0;
     self->ap_key_len = 0;
+    strncpy(self->hostname, MICROPY_BOARD_HOSTNAME, MICROPY_BOARD_HOSTNAME_LENGTH);
+    self->hostname[MICROPY_BOARD_HOSTNAME_LENGTH - 1] = 0;
 
     cyw43_poll = NULL;
 }

drivers/cyw43/cyw43_lwip.c

@@ -117,7 +117,7 @@ void cyw43_tcpip_init(cyw43_t *self, int itf) {
     #else
     netif_add(n, &ipconfig[0], &ipconfig[1], &ipconfig[2], self, cyw43_netif_init, netif_input);
     #endif
-    netif_set_hostname(n, "PYBD");
+    netif_set_hostname(n, self->hostname);
     netif_set_default(n);
     netif_set_up(n);
 
@@ -132,8 +132,9 @@ void cyw43_tcpip_init(cyw43_t *self, int itf) {
     #if LWIP_MDNS_RESPONDER
     // TODO better to call after IP address is set
     char mdns_hostname[9];
-    memcpy(&mdns_hostname[0], "PYBD", 4);
-    mp_hal_get_mac_ascii(MP_HAL_MAC_WLAN0, 8, 4, &mdns_hostname[4]);
+    int len = MIN(strlen(self->hostname), 4);
+    memcpy(&mdns_hostname[0], self->hostname, len);
+    mp_hal_get_mac_ascii(MP_HAL_MAC_WLAN0, 4 + len, 8 - len, &mdns_hostname[len]);
     mdns_hostname[8] = '\0';
     mdns_resp_add_netif(n, mdns_hostname, 60);
     #endif