text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * Development of the code in this file was sponsored by Microbric Pty Ltd
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdio.h>
  #include <string.h>
  
  #include "freertos/FreeRTOS.h"
  #include "freertos/task.h"
  #include "rom/uart.h"
  
  #include "py/obj.h"
  #include "py/mpstate.h"
  #include "py/mphal.h"
  #include "extmod/misc.h"
  #include "lib/utils/pyexec.h"
  #include "mphalport.h"
  
  #include "service_nus.h"
  
  TaskHandle_t mp_main_task_handle;
  
  STATIC uint8_t stdin_ringbuf_array[256];
  ringbuf_t stdin_ringbuf = {stdin_ringbuf_array, sizeof(stdin_ringbuf_array)};
  
  int mp_hal_stdin_rx_chr(void) {
      for (;;) {
          int c = ringbuf_get(&stdin_ringbuf);
          if (c != -1) {
              return c;
          }
          MICROPY_EVENT_POLL_HOOK
          ulTaskNotifyTake(pdFALSE, 1);
      }
  }
  
  void mp_hal_stdout_tx_str(const char *str) {
      mp_hal_stdout_tx_strn(str, strlen(str));
  }
  
  void mp_hal_stdout_tx_strn(const char *str, uint32_t len) {
      // Only release the GIL if many characters are being sent
      bool release_gil = len > 20;
      if (release_gil) {
          MP_THREAD_GIL_EXIT();
      }
      for (uint32_t i = 0; i < len; ++i) {    // Send via UART
          uart_tx_one_char(str[i]);
      }
      nus_rx_notify( str, len );              // Send via BLE NUS
  
      if (release_gil) {
          MP_THREAD_GIL_ENTER();
      }
      mp_uos_dupterm_tx_strn(str, len);
  }
  
  // Efficiently convert "\n" to "\r\n"
  void mp_hal_stdout_tx_strn_cooked(const char *str, size_t len) {
      const char *last = str;
      while (len--) {
          if (*str == '\n') {
              if (str > last) {
                  mp_hal_stdout_tx_strn(last, str - last);
              }
              mp_hal_stdout_tx_strn("\r\n", 2);
              ++str;
              last = str;
          } else {
              ++str;
          }
      }
      if (str > last) {
          mp_hal_stdout_tx_strn(last, str - last);
      }
  }
  
  uint32_t mp_hal_ticks_ms(void) {
      return esp_timer_get_time() / 1000;
  }
  
  uint32_t mp_hal_ticks_us(void) {
      return esp_timer_get_time();
  }
  
  void mp_hal_delay_ms(uint32_t ms) {
      uint64_t us = ms * 1000;
      uint64_t dt;
      uint64_t t0 = esp_timer_get_time();
      for (;;) {
          uint64_t t1 = esp_timer_get_time();
          dt = t1 - t0;
          if (dt + portTICK_PERIOD_MS * 1000 >= us) {
              // doing a vTaskDelay would take us beyond requested delay time
              break;
          }
          MICROPY_EVENT_POLL_HOOK
          if( (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) ){
              t1 = esp_timer_get_time();
              dt = t1 - t0;
              vTaskDelay( ((us - dt)/1000) / portTICK_PERIOD_MS ); // since scheduler is idle we can vTaskDelay
          }
          ulTaskNotifyTake(pdFALSE, 1);
      }
      if (dt < us) {
          // do the remaining delay accurately
          mp_hal_delay_us(us - dt);
      }
  }
  
  void mp_hal_delay_us(uint32_t us) {
      // these constants are tested for a 240MHz clock
      const uint32_t this_overhead = 5;
      const uint32_t pend_overhead = 150;
  
      // return if requested delay is less than calling overhead
      if (us < this_overhead) {
          return;
      }
      us -= this_overhead;
  
      uint64_t t0 = esp_timer_get_time();
      for (;;) {
          uint64_t dt = esp_timer_get_time() - t0;
          if (dt >= us) {
              return;
          }
          if (dt + pend_overhead < us) {
              // we have enough time to service pending events
              // (don't use MICROPY_EVENT_POLL_HOOK because it also yields)
              mp_handle_pending();
          }
      }
  }
  
  /*
  extern int mp_stream_errno;
  int *__errno() {
      return &mp_stream_errno;
  }
  */
  
  // Wake up the main task if it is sleeping
  void mp_hal_wake_main_task_from_isr(void) {
      BaseType_t xHigherPriorityTaskWoken = pdFALSE;
      vTaskNotifyGiveFromISR(mp_main_task_handle, &xHigherPriorityTaskWoken);
      if (xHigherPriorityTaskWoken == pdTRUE) {
          portYIELD_FROM_ISR();
      }
  }
  