Shorter paths to HAL, ExtUI (#17156)

Marlin/src/HAL/STM32F1/SoftwareSerial.h

@@ -0,0 +1,44 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+#include <stdint.h>
+
+#ifndef HAVE_SW_SERIAL
+   #define SW_SERIAL_PLACEHOLDER 1
+#endif
+
+class SoftwareSerial {
+public:
+  SoftwareSerial(int8_t RX_pin, int8_t TX_pin);
+
+  void begin(const uint32_t baudrate);
+
+  bool available();
+
+  uint8_t read();
+  uint16_t write(uint8_t byte);
+  void flush();
+
+  void listen();
+  void stopListening();
+
+protected:
+  bool listening;
+};