Split into main/net/tusb_config, extract ring_buffer and usb_cdc headers

net.cpp

@@ -0,0 +1,24 @@
+#include "net.h"
+#include "pico/unique_id.h"
+#include "w6300.h"
+
+bool net_init() {
+    w6300::init_spi();
+    w6300::init_critical_section();
+    w6300::reset();
+    w6300::init();
+    if (!w6300::check()) return false;
+
+    pico_unique_board_id_t uid;
+    pico_get_unique_board_id(&uid);
+    w6300::net_info info = {};
+    info.mac[0] = (uid.id[0] & 0xFC) | 0x02;
+    info.mac[1] = uid.id[1];
+    info.mac[2] = uid.id[2];
+    info.mac[3] = uid.id[3];
+    info.mac[4] = uid.id[4];
+    info.mac[5] = uid.id[5];
+    w6300::init_net(info);
+
+    return true;
+}