STM32F1 HAL

Adding files for STM32F1 HAL based on libmaple/stm32duino core.
Current persistent_store uses cardreader changes to be sent in separate
commit, but could be changed to use i2c eeprom.

Marlin/src/HAL/HAL_STM32F1/HAL_Stm32f1.cpp

@@ -0,0 +1,138 @@
+/**
+ * Marlin 3D Printer Firmware
+ *
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2016 Bob Cousins bobcousins42@googlemail.com
+ * Copyright (c) 2015-2016 Nico Tonnhofer wurstnase.reprap@gmail.com
+ * Copyright (c) 2017 Victor Perez
+ *
+ * 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/>.
+ *
+ */
+
+/**
+ * HAL for stm32duino.com based on Libmaple and compatible (STM32F1)
+ */
+
+#ifdef __STM32F1__
+
+// --------------------------------------------------------------------------
+// Includes
+// --------------------------------------------------------------------------
+
+#include "../HAL.h"
+
+//#include <Wire.h>
+
+// --------------------------------------------------------------------------
+// Externals
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Local defines
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Types
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Variables
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Public Variables
+// --------------------------------------------------------------------------
+
+uint16_t HAL_adc_result;
+
+// --------------------------------------------------------------------------
+// Private Variables
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Function prototypes
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Private functions
+// --------------------------------------------------------------------------
+
+// --------------------------------------------------------------------------
+// Public functions
+// --------------------------------------------------------------------------
+
+/* VGPV Done with defines
+// disable interrupts
+void cli(void) { noInterrupts(); }
+
+// enable interrupts
+void sei(void) { interrupts(); }
+*/
+
+void HAL_clear_reset_source(void) { }
+
+/**
+ * TODO: Check this and change or remove.
+ * currently returns 1 that's equal to poweron reset.
+ */
+uint8_t HAL_get_reset_source(void) { return 1; }
+
+void _delay_ms(const int delay_ms) { delay(delay_ms); }
+
+extern "C" {
+  extern unsigned int _ebss; // end of bss section
+}
+
+/**
+ * TODO: Change this to correct it for libmaple
+ */
+
+// return free memory between end of heap (or end bss) and whatever is current
+
+/*
+#include "wirish/syscalls.c"
+//extern caddr_t _sbrk(int incr);
+#ifndef CONFIG_HEAP_END
+extern char _lm_heap_end;
+#define CONFIG_HEAP_END ((caddr_t)&_lm_heap_end)
+#endif
+
+extern "C" {
+  static int freeMemory() {
+    char top = 't';
+    return &top - reinterpret_cast<char*>(sbrk(0));
+  }
+  int freeMemory() {
+    int free_memory;
+    int heap_end = (int)_sbrk(0);
+    free_memory = ((int)&free_memory) - ((int)heap_end);
+    return free_memory;
+  }
+}
+*/
+
+// --------------------------------------------------------------------------
+// ADC
+// --------------------------------------------------------------------------
+
+void HAL_adc_start_conversion(const uint8_t adc_pin) {
+  HAL_adc_result = (analogRead(adc_pin) >> 2) & 0x3ff; // shift to get 10 bits only.
+}
+
+uint16_t HAL_adc_get_result(void) {
+  return HAL_adc_result;
+}
+
+#endif // __STM32F1__