Just a one byte parameter works better in this case.

cmd/handlers.c

@@ -303,8 +303,11 @@ static void ICACHE_FLASH_ATTR cmdWifiSignalStrength(CmdPacket *cmd) {
     return;
   }
 
-  int32_t i;
-  cmdPopArg(&req, (uint8_t*)&i, 4);
+  char x;
+  // int32_t i;
+  // cmdPopArg(&req, (uint8_t*)&i, 4);
+  cmdPopArg(&req, (uint8_t*)&x, 1);
+  int i = x;
   os_printf("cmdWifiSignalStrength: argc %d, ", argc);
   os_printf("i %d\n", i);
 

esp-link/cgiwifi.c

@@ -979,5 +979,12 @@ ICACHE_FLASH_ATTR int wifiSignalStrength(int i) {
     rssi = 0;				// FIX ME
   else
     rssi = cgiWifiAps.apData[i]->rssi;	// Signal strength of any known network
+
+  os_printf("RSSIs : ");
+  for (int j=0; j<cgiWifiAps.noAps; j++) {
+    int rssi = cgiWifiAps.apData[j]->rssi;
+    os_printf("%d ", rssi);
+  }
+  os_printf("\n");
   return rssi;
 }