IPv6 initial support from @oddstr13 (#748)

* Apply @oddstr13 multicast patch to cyw43 driver
* Initial work for enabling IPv6
* Allow accessing CYW43 stats when LWIP_SYS_CHECK_MS is not set
* Use cyw43_set_allmulti to allow receiving multicast
* Add tools/libpico/build to gitignore
Co-authored-by: Odd Stråbø <oddstr13@openshell.no>

.gitignore

 .DS_Store
 system
 tools/dist
+tools/libpico/build

.gitmodules

@@ -3,7 +3,7 @@
 	url = https://github.com/earlephilhower/ArduinoCore-API.git
 [submodule "pico-sdk"]
 	path = pico-sdk
-	url = https://github.com/raspberrypi/pico-sdk.git
+	url = https://github.com/earlephilhower/pico-sdk.git
 [submodule "system/pyserial"]
 	path = tools/pyserial
 	url = https://github.com/pyserial/pyserial.git

cores/rp2040/sdkoverride/cyw43_arch_threadsafe_background.c

@@ -89,7 +89,7 @@ semaphore_t cyw43_irq_sem;
 
 // Called in low priority pendsv interrupt only to do lwip processing and check cyw43 sleep
 static void periodic_worker(void) {
-#if CYW43_USE_STATS
+#if CYW43_USE_STATS && LWIP_SYS_CHECK_MS
     static uint32_t counter;
     if (counter++ % (30000 / LWIP_SYS_CHECK_MS) == 0) {
         cyw43_dump_stats();

include/lwipopts.h

@@ -53,6 +53,10 @@ extern void interrupts();
 #define DHCP_DOES_ARP_CHECK         0
 #define LWIP_DHCP_DOES_ACD_CHECK    0
 
+#if LWIP_IPV6
+#define LWIP_IPV6_DHCP6             1
+#endif
+
 // NTP
 extern void __setSystemTime(unsigned long long sec, unsigned long us);
 #define SNTP_SET_SYSTEM_TIME_US(sec, us)  __setSystemTime(sec, us)

libraries/lwIP_CYW43/src/utility/CYW43shim.cpp

@@ -50,6 +50,10 @@ bool CYW43::begin(const uint8_t* address, netif* netif) {
             authmode = CYW43_AUTH_OPEN;
         }
 
+        // Not currently possible to hook up igmp_mac_filter and mld_mac_filter
+        // TODO: implement igmp_mac_filter and mld_mac_filter
+        cyw43_set_allmulti(_self, true);
+
         if (cyw43_arch_wifi_connect_timeout_ms(_ssid, _password, authmode, _timeout)) {
             return false;
         } else {

libraries/lwIP_Ethernet/src/LwipIntfDev.h

@@ -32,7 +32,9 @@
 #include <lwip/init.h>
 #include <lwip/netif.h>
 #include <lwip/etharp.h>
+#include <lwip/ethip6.h>
 #include <lwip/dhcp.h>
+#include <lwip/dhcp6.h>
 #include <lwip/dns.h>
 #include <lwip/raw.h>
 #include <lwip/icmp.h>
@@ -366,6 +368,14 @@ boolean LwipIntfDev<RawDev>::begin(const uint8_t* macAddress, const uint16_t mtu
         netif_set_up(&_netif);
     }
 
+#if LWIP_IPV6
+    netif_create_ip6_linklocal_address(&_netif, true);
+#endif
+#if LWIP_IPV6_DHCP6_STATELESS
+    err_t __res = dhcp6_enable_stateless(&_netif);
+    DEBUGV("LwipIntfDev: Enabled DHCP6 stateless: %d\n", __res);
+#endif
+
     _started = true;
 
     if (_intrPin >= 0) {
@@ -444,11 +454,19 @@ err_t LwipIntfDev<RawDev>::netif_init() {
     _netif.chksum_flags = NETIF_CHECKSUM_ENABLE_ALL;
     _netif.flags = NETIF_FLAG_ETHARP | NETIF_FLAG_IGMP | NETIF_FLAG_BROADCAST | NETIF_FLAG_LINK_UP;
 
+#if LWIP_IPV6_MLD
+    _netif.flags |= NETIF_FLAG_MLD6;
+#endif
+
     // lwIP's doc: This function typically first resolves the hardware
     // address, then sends the packet.  For ethernet physical layer, this is
     // usually lwIP's etharp_output()
     _netif.output = etharp_output;
 
+#if LWIP_IPV6
+    _netif.output_ip6 = ethip6_output;
+#endif
+
     // lwIP's doc: This function outputs the pbuf as-is on the link medium
     // (this must points to the raw ethernet driver, meaning: us)
     _netif.linkoutput = linkoutput_s;

pico-sdk @ 453cae23

-Subproject commit 2e6142b15b8a75c1227dd3edbe839193b2bf9041
+Subproject commit 453cae2399959361bbbb941fd52abe2452dcb16c

tools/libpico/lwipopts.h

@@ -53,6 +53,10 @@ extern void interrupts();
 #define DHCP_DOES_ARP_CHECK         0
 #define LWIP_DHCP_DOES_ACD_CHECK    0
 
+#if LWIP_IPV6
+#define LWIP_IPV6_DHCP6             1
+#endif
+
 // NTP
 extern void __setSystemTime(unsigned long long sec, unsigned long us);
 #define SNTP_SET_SYSTEM_TIME_US(sec, us)  __setSystemTime(sec, us)