[core] Refactor SerialClass as API library

cores/common/arduino/libraries/api/Serial/Serial.cpp

@@ -0,0 +1,34 @@
+/* Copyright (c) Kuba Szczodrzyński 2023-05-23. */
+
+#include "Serial.h"
+
+SerialClass::SerialClass(uint32_t port) {
+	this->port = port;
+	this->buf  = NULL;
+	this->data = NULL;
+}
+
+#if LT_AUTO_DOWNLOAD_REBOOT && defined(LT_UART_ADR_PATTERN)
+static uint8_t adrState = 0;
+static uint8_t adrCmd[] = {LT_UART_ADR_PATTERN};
+
+void SerialClass::adrParse(uint8_t c) {
+	adrState = (adrState + 1) * (c == adrCmd[adrState]);
+	if (adrState == sizeof(adrCmd) / sizeof(uint8_t)) {
+		LT_I("Auto download mode: rebooting");
+		LT.restartDownloadMode();
+	}
+}
+#endif
+
+int SerialClass::available() {
+	return this->buf && this->buf->available();
+}
+
+int SerialClass::peek() {
+	return this->buf ? this->buf->peek() : -1;
+}
+
+int SerialClass::read() {
+	return this->buf ? this->buf->read_char() : -1;
+}

cores/common/arduino/libraries/api/Serial/Serial.h

@@ -0,0 +1,46 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-06-23. */
+
+#pragma once
+
+#include <Arduino.h>
+#include <api/HardwareSerial.h>
+#include <api/RingBuffer.h>
+
+using namespace arduino;
+
+class SerialClass : public HardwareSerial {
+  private:
+	uint32_t port;
+	RingBuffer *buf;
+
+  public:
+	void *data;
+
+  public:
+	SerialClass(uint32_t port);
+
+	inline void begin(unsigned long baudrate) {
+		begin(baudrate, SERIAL_8N1);
+	}
+
+	void begin(unsigned long baudrate, uint16_t config);
+	void end();
+	int available();
+	int peek();
+	int read();
+	void flush();
+	size_t write(uint8_t c);
+
+	operator bool() {
+		return !!buf;
+	}
+
+  public:
+#if LT_AUTO_DOWNLOAD_REBOOT
+	static void adrParse(uint8_t c);
+#endif
+
+	using Print::write;
+};
+
+#define HAS_SERIAL_CLASS 1

cores/common/arduino/src/Arduino.h

@@ -42,6 +42,7 @@ using std::min;
 #if defined(__cplusplus) && LT_ARD_HAS_SERIAL
 #include <Serial.h>
 
+#if HAS_SERIAL_CLASS
 #if HAS_SERIAL0
 extern SerialClass Serial0;
 #endif
@@ -51,6 +52,7 @@ extern SerialClass Serial1;
 #if HAS_SERIAL2
 extern SerialClass Serial2;
 #endif
+#endif
 
 #define SerialN(x) Serial##x
 #define SerialM(x) SerialN(x)

cores/common/arduino/src/wiring_custom.h

@@ -21,6 +21,8 @@ extern "C" {
 #define PIN_SWD	 (1 << 10)
 #define PIN_UART (1 << 11)
 
+#define PIN_INVALID 255
+
 typedef struct {
 	/**
 	 * @brief GPIO name in the family SDK.