text: /* USER CODE BEGIN Header */
  /**
    ******************************************************************************
    * @file    usart.c
    * @brief   This file provides code for the configuration
    *          of the USART instances.
    ******************************************************************************
    * @attention
    *
    * Copyright (c) 2022 STMicroelectronics.
    * All rights reserved.
    *
    * This software is licensed under terms that can be found in the LICENSE file
    * in the root directory of this software component.
    * If no LICENSE file comes with this software, it is provided AS-IS.
    *
    ******************************************************************************
    */
  /* USER CODE END Header */
  /* Includes ------------------------------------------------------------------*/
  #include "usart1.h"
  #include <sys/unistd.h> // STDOUT_FILENO, STDERR_FI
  #include <errno.h>
  
  /* USER CODE BEGIN 0 */
  
  /* USER CODE END 0 */
  
  UART_HandleTypeDef huart1;
  
  /* USART1 init function */
  
  void USART1_initUart(void)
  {
  
    /* USER CODE BEGIN USART1_Init 0 */
  
    /* USER CODE END USART1_Init 0 */
  
    /* USER CODE BEGIN USART1_Init 1 */
  
    /* USER CODE END USART1_Init 1 */
    huart1.Instance = USART1;
    huart1.Init.BaudRate = 115200;
    huart1.Init.WordLength = UART_WORDLENGTH_8B;
    huart1.Init.StopBits = UART_STOPBITS_1;
    huart1.Init.Parity = UART_PARITY_NONE;
    huart1.Init.Mode = UART_MODE_TX_RX;
    huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart1.Init.OverSampling = UART_OVERSAMPLING_16;
    huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
    huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_SWAP_INIT;
    huart1.AdvancedInit.Swap = UART_ADVFEATURE_SWAP_ENABLE;
    if (HAL_UART_Init(&huart1) != HAL_OK)
    {
      __disable_irq();
      while (1)
      {
      }
    }
    /* USER CODE BEGIN USART1_Init 2 */
  
    /* USER CODE END USART1_Init 2 */
  
  }
  
  void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
  {
  
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    if(uartHandle->Instance==USART1)
    {
    /* USER CODE BEGIN USART1_MspInit 0 */
  
    /* USER CODE END USART1_MspInit 0 */
      /* USART1 clock enable */
      __HAL_RCC_USART1_CLK_ENABLE();
  
      __HAL_RCC_GPIOB_CLK_ENABLE();
      /**USART1 GPIO Configuration
      PB6     ------> USART1_TX
      PB7     ------> USART1_RX
      */
      GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
      GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
      GPIO_InitStruct.Pull = GPIO_NOPULL;
      GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
      GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
      HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
  
    /* USER CODE BEGIN USART1_MspInit 1 */
  
    /* USER CODE END USART1_MspInit 1 */
    }
  }
  
  void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
  {
  
    if(uartHandle->Instance==USART1)
    {
    /* USER CODE BEGIN USART1_MspDeInit 0 */
  
    /* USER CODE END USART1_MspDeInit 0 */
      /* Peripheral clock disable */
      __HAL_RCC_USART1_CLK_DISABLE();
  
      /**USART1 GPIO Configuration
      PB6     ------> USART1_TX
      PB7     ------> USART1_RX
      */
      HAL_GPIO_DeInit(GPIOB, GPIO_PIN_6|GPIO_PIN_7);
  
    /* USER CODE BEGIN USART1_MspDeInit 1 */
  
    /* USER CODE END USART1_MspDeInit 1 */
    }
  }
  
  int Usart1_Send(int file, char *data, int len){
    if ((file != STDOUT_FILENO) && (file != STDERR_FILENO))
      {
          errno = EBADF;
          return -1;
      }
  
      // arbitrary timeout 1000
      HAL_StatusTypeDef status = HAL_UART_Transmit(&huart1, (uint8_t *)data, len, 1000);
  
      // return # of bytes written - as best we can tell
      return (status == HAL_OK ? len : 0);
  }