Add Pico W WiFi support (#670)

* Add support for the WiFi chip on the Pico W board.
* USB interrupt now no longer hard coded (conflicted with the WiFi IRQ).
* Add in Pico W board to makeboards.py
* Add in GPIO and variant support
* Initialize WiFi in the Variant
* Use manual LWIP, fix size accounting
* Remove the SDK WiFi overrides
* Pulling in work done in the ESP8266 core.
* Make IPAddress support IPv6
* Build LWIP with IPv4 and IPv6 support
* Use proper MAC
* Avoid cyw_warn crash.  Make macro to a comment while building
* Add WiFiServer
* Add WiFiUdp
* Move LWIP-specific support files to LWIP_Ethernet
* Add WiFi::ping (ICMP ping)
* Move ICMP echo (ping) to LWIPIntfDev
* Move hostByName to LwipIntfDev
* Add AP mode with simple DHCP server
* Add some examples and basic ESP8266 compat hacks
* Update Adafruit TinyUSB to fix crash
* Set DHCP hostname
* Make Wifi.begin() return CONNECTED with link + IP
* Return connected() on WiFi::begin
* Fix spurious TCP retransmission
* Protect LWIP from reentrancy

The Pico SDK calls "sys_check_timeouts() from inside a periodic interrupt.
This appears unsafe, as the interrupt could happen while already in the
(non-reentrant) LWIP code.

Block the interrupt from calling sys_check_timeouts by using a global flag
manually set via an RAII recursive lock.

Add interrupt protection macros around critical sections inside LWIP via
the standard defines.

These two changes should make LWIP significantly more stable and long
running.

* Support disconnecting and reconnecting WiFi
* Add WiFiServer simple example
* Update documentation

Fixes #666
Fixed #665

Author: earlephilhower

README.md

@@ -11,6 +11,7 @@ See https://arduino-pico.readthedocs.io/en/latest/ along with the examples for m
 
 # Supported Boards
 * Raspberry Pi Pico
+* Raspberry Pi Pico W
 * Adafruit Feather RP2040
 * Adafruit ItsyBitsy RP2040
 * Adafruit KB2040
@@ -177,8 +178,10 @@ If you want to contribute or have bugfixes, drop me a note at <earlephilhower@ya
 * [Arduino-Pico](https://github.com/earlephilhower/arduino-pico) core files are licensed under the LGPL.
 * [LittleFS](https://github.com/ARMmbed/littlefs) library written by ARM Limited and released under the [BSD 3-clause license](https://github.com/ARMmbed/littlefs/blob/master/LICENSE.md).
 * [UF2CONV.PY](https://github.com/microsoft/uf2) is by Microsoft Corporation and licensed under the MIT license.
-* Some filesystem code taken from the [ESP8266 Arduino Core](https://github.com/esp8266/Arduino) and licensed under the LGPL.
+* Networking and filesystem code taken from the [ESP8266 Arduino Core](https://github.com/esp8266/Arduino) and licensed under the LGPL.
+* DHCP server for AP host mode from the [Micropython Project](https://micropython.org), distributed under the MIT License.
 * [FreeRTOS](https://freertos.org) is Copyright Amazon.com, Inc. or its affiliates, and distributed under the MIT license.
+* [lwIP](https://savannah.nongnu.org/projects/lwip/) is (c) the Swedish Institute of Computer Science and licenced under the BSD license.
 
 -Earle F. Philhower, III
  [email protected]

boards.txt

@@ -18,8 +18,7 @@
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#ifndef Arduino_h
-#define Arduino_h
+#pragma once
 
 #include <stdint.h>
 #include <stdlib.h>
@@ -112,5 +111,3 @@ constexpr uint32_t __bitset(const int (&a)[N], size_t i = 0U) {
     return i < N ? (1L << a[i]) | __bitset(a, i + 1) : 0;
 }
 #endif
-
-#endif // Arduino_h

cores/rp2040/Arduino.h

@@ -18,8 +18,7 @@
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#ifndef FS_H
-#define FS_H
+#pragma once
 
 #include <memory>
 #include <Arduino.h>
@@ -264,5 +263,3 @@ using fs::SeekEnd;
 using fs::FSInfo;
 using fs::FSConfig;
 #endif //FS_NO_GLOBALS
-
-#endif //FS_H

cores/rp2040/FS.h

@@ -17,8 +17,8 @@
     License along with this library; if not, write to the Free Software
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
-#ifndef FSIMPL_H
-#define FSIMPL_H
+
+#pragma once
 
 #include <stddef.h>
 #include <stdint.h>
@@ -149,5 +149,3 @@ class FSImpl {
 };
 
 } // namespace fs
-
-#endif //FSIMPL_H

cores/rp2040/FSImpl.h

@@ -0,0 +1,41 @@
+/*
+    WiFiMutex.h - Ensure the timer-driven sys_check_timeouts doesn't
+                  get executed while we're in the user-level TCP stack.
+    Copyright (c) 2022 Earle F. Philhower, III.  All rights reserved.
+
+    Implements the API defined by the Arduino WiFiNINA library,
+    copyright (c) 2018 Arduino SA. All rights reserved.
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library 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 GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+
+extern "C" volatile bool __inLWIP;
+
+class LWIPMutex {
+public:
+    LWIPMutex() {
+        __inLWIP = true;
+        _ref++;
+    }
+    ~LWIPMutex() {
+        if (0 == --_ref) {
+            __inLWIP = false;
+        }
+    }
+private:
+    static int _ref;
+};

cores/rp2040/LWIPMutex.h

@@ -40,7 +40,7 @@ mutex_t __usb_mutex;
 
 // USB processing will be a periodic timer task
 #define USB_TASK_INTERVAL 1000
-#define USB_TASK_IRQ 31
+static int __usb_task_irq;
 
 // USB VID/PID (note that PID can change depending on the add'l interfaces)
 #define USBD_VID (0x2E8A) // Raspberry Pi
@@ -284,7 +284,7 @@ static void usb_irq() {
 }
 
 static int64_t timer_task(__unused alarm_id_t id, __unused void *user_data) {
-    irq_set_pending(USB_TASK_IRQ);
+    irq_set_pending(__usb_task_irq);
     return USB_TASK_INTERVAL;
 }
 
@@ -303,8 +303,9 @@ void __USBStart() {
 
     tusb_init();
 
-    irq_set_exclusive_handler(USB_TASK_IRQ, usb_irq);
-    irq_set_enabled(USB_TASK_IRQ, true);
+    __usb_task_irq = user_irq_claim_unused(true);
+    irq_set_exclusive_handler(__usb_task_irq, usb_irq);
+    irq_set_enabled(__usb_task_irq, true);
 
     add_alarm_in_us(USB_TASK_INTERVAL, timer_task, NULL, true);
 }

cores/rp2040/RP2040USB.cpp

@@ -18,8 +18,7 @@
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#ifndef __SERIALUSB_H__
-#define __SERIALUSB_H__
+#pragma once
 
 #include <Arduino.h>
 #include "api/HardwareSerial.h"
@@ -54,5 +53,3 @@ extern SerialUSB Serial;
 namespace arduino {
 extern void serialEventRun(void) __attribute__((weak));
 };
-
-#endif