AMiRo-OS

/************************************************************************************//**

* \file         Demo\ARMCM3_STM32_Olimex_STM32P103_GCC\Boot\main.c

* \brief        Bootloader application source file.

* \ingroup      Boot_ARMCM3_STM32_Olimex_STM32P103_GCC

* \internal

*----------------------------------------------------------------------------------------

*                          C O P Y R I G H T

*----------------------------------------------------------------------------------------

*   Copyright (c) 2012  by Feaser    http://www.feaser.com    All rights reserved

*

*----------------------------------------------------------------------------------------

*                            L I C E N S E

*----------------------------------------------------------------------------------------

* This file is part of OpenBLT. OpenBLT 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.

*

* OpenBLT 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 OpenBLT.

* If not, see <http://www.gnu.org/licenses/>.

*

* A special exception to the GPL is included to allow you to distribute a combined work

* that includes OpenBLT without being obliged to provide the source code for any

* proprietary components. The exception text is included at the bottom of the license

* file <license.html>.

*

* \endinternal

****************************************************************************************/

/****************************************************************************************

* Include files

****************************************************************************************/

#include "boot.h"                                /* bootloader generic header          */

#include "timer.h"

#include "ARMCM3_STM32/types.h"

#include "AMiRo/amiroblt.h"

#include "helper.h"

#include "iodef.h"

/****************************************************************************************

* Defines

****************************************************************************************/

/****************************************************************************************

* Function prototypes

****************************************************************************************/

static void Init(void);

static void initGpio();

static void initExti();

void configGpioForShutdown();

ErrorStatus handleWarmReset();

ErrorStatus shutdownDisambiguationProcedure(const uint8_t type);

void shutdownToTransportation(const blt_bool exec_disambiguation);

void shutdownToDeepsleep(const blt_bool exec_disambiguation);

void shutdownToHibernate(const blt_bool exec_disambiguation);

void shutdownAndRestart(const blt_bool exec_disambiguation);

volatile blBackupRegister_t backup_reg;

/****************************************************************************************

* Callback configuration

****************************************************************************************/

void blCallbackShutdownTransportation(void);

void blCallbackShutdownDeepsleep(void);

void blCallbackShutdownHibernate(void);

void blCallbackShutdownRestart(void);

void blCallbackHandleShutdownRequest(void);

const blCallbackTable_t cbtable __attribute__ ((section ("_callback_table"))) = {

  .magicNumber = BL_MAGIC_NUMBER,

  .vBootloader = {BL_VERSION_ID_AMiRoBLT_Beta, BL_VERSION_MAJOR, BL_VERSION_MINOR, 0},

  .vSSSP = {BL_VERSION_ID_SSSP, BL_SSSP_VERSION_MAJOR, BL_SSSP_VERSION_MINOR, 0},

  .vCompiler = {BL_VERSION_ID_GCC, __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__},  // currently only GCC is supported

  .cbShutdownHibernate = blCallbackShutdownHibernate,

  .cbShutdownDeepsleep = blCallbackShutdownDeepsleep,

  .cbShutdownTransportation = blCallbackShutdownTransportation,

  .cbShutdownRestart = blCallbackShutdownRestart,

  .cbHandleShutdownRequest = blCallbackHandleShutdownRequest,

  .cb5 = (void*)0,

  .cb6 = (void*)0,

  .cb7 = (void*)0,

  .cb8 = (void*)0,

  .cb9 = (void*)0,

  .cb10 = (void*)0,

  .cb11 = (void*)0

};

/************************************************************************************//**

** \brief     This is the entry point for the bootloader application and is called

**            by the reset interrupt vector after the C-startup routines executed.

** \return    Program return code.

**

****************************************************************************************/

int main(void)

{

  /* initialize the microcontroller */

  Init();

  /* activate some required clocks */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD, ENABLE);

  /* initialize GPIOs and EXTI lines */

  initGpio();

  setLed(BLT_TRUE);

  initExti();

  /* initialize the timer */

  TimerInit();

  /* detect the primary reason for this wakeup/restart */

  backup_reg.wakeup_pri_reason =

      ((RCC_GetFlagStatus(RCC_FLAG_LPWRRST) == SET) ? BL_WAKEUP_PRI_RSN_LPWRRST : 0) |

      ((RCC_GetFlagStatus(RCC_FLAG_WWDGRST) == SET) ? BL_WAKEUP_PRI_RSN_WWDGRST : 0) |

      ((RCC_GetFlagStatus(RCC_FLAG_IWDGRST) == SET) ? BL_WAKEUP_PRI_RSN_IWDGRST : 0) |

      ((RCC_GetFlagStatus(RCC_FLAG_SFTRST) == SET) ? BL_WAKEUP_PRI_RSN_SFTRST : 0)   |

      ((RCC_GetFlagStatus(RCC_FLAG_PORRST) == SET) ? BL_WAKEUP_PRI_RSN_PORRST : 0)   |

      ((RCC_GetFlagStatus(RCC_FLAG_PINRST) == SET) ? BL_WAKEUP_PRI_RSN_PINRST : 0)   |

      ((PWR_GetFlagStatus(PWR_FLAG_WU) == SET) ? BL_WAKEUP_PRI_RSN_WKUP : 0);

  /* for this module there is no secondary wakeup reason */

  backup_reg.wakeup_sec_reason = BL_WAKEUP_SEC_RSN_UNKNOWN;

  /* clear the flags */

  RCC_ClearFlag();

  PWR_ClearFlag(PWR_FLAG_WU);

  setLed(BLT_FALSE);

  /* handle different wakeup/reset reasons */

  ErrorStatus status = ERROR;

  if (backup_reg.wakeup_pri_reason & BL_WAKEUP_PRI_RSN_PINRST) {

    /* system was woken via NRST pin */

    status = handleWarmReset();

  } else {

    /* system was woken/reset for an unexpected reason */

    blinkSOS(1);

    status = handleWarmReset();

  }

  /* if something went wrong, signal this failure */

  if (status != SUCCESS) {

    blinkSOSinf();

  }

  return 0;

} /*** end of main ***/

/************************************************************************************//**

** \brief     Initializes the microcontroller.

** \return    none.

**

****************************************************************************************/

static void Init(void)

{

  volatile blt_int32u StartUpCounter = 0, HSEStatus = 0;

  blt_int32u pll_multiplier;

#if (BOOT_FILE_LOGGING_ENABLE > 0) && (BOOT_COM_UART_ENABLE == 0) && (BOOT_GATE_UART_ENABLE == 0)

  GPIO_InitTypeDef  GPIO_InitStruct;

  USART_InitTypeDef USART_InitStruct;

#endif

  /* reset the RCC clock configuration to the default reset state (for debug purpose) */

  /* set HSION bit */

  RCC->CR |= (blt_int32u)0x00000001;

  /* reset SW, HPRE, PPRE1, PPRE2, ADCPRE and MCO bits */

  RCC->CFGR &= (blt_int32u)0xF8FF0000;

  /* reset HSEON, CSSON and PLLON bits */

  RCC->CR &= (blt_int32u)0xFEF6FFFF;

  /* reset HSEBYP bit */

  RCC->CR &= (blt_int32u)0xFFFBFFFF;

  /* reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE/OTGFSPRE bits */

  RCC->CFGR &= (blt_int32u)0xFF80FFFF;

  /* disable all interrupts and clear pending bits  */

  RCC->CIR = 0x009F0000;

  /* enable HSE */

  RCC->CR |= ((blt_int32u)RCC_CR_HSEON);

  /* wait till HSE is ready and if Time out is reached exit */

  do

  {

    HSEStatus = RCC->CR & RCC_CR_HSERDY;

    StartUpCounter++;

  }

  while((HSEStatus == 0) && (StartUpCounter != 1500));

  /* check if time out was reached */

  if ((RCC->CR & RCC_CR_HSERDY) == RESET)

  {

    /* cannot continue when HSE is not ready */

    ASSERT_RT(BLT_FALSE);

  }

  /* enable flash prefetch buffer */

  FLASH->ACR |= FLASH_ACR_PRFTBE;

  /* reset flash wait state configuration to default 0 wait states */

  FLASH->ACR &= (blt_int32u)((blt_int32u)~FLASH_ACR_LATENCY);

#if (BOOT_CPU_SYSTEM_SPEED_KHZ > 48000)

  /* configure 2 flash wait states */

  FLASH->ACR |= (blt_int32u)FLASH_ACR_LATENCY_2;

#elif (BOOT_CPU_SYSTEM_SPEED_KHZ > 24000)

  /* configure 1 flash wait states */

  FLASH->ACR |= (blt_int32u)FLASH_ACR_LATENCY_1;

#endif

  /* HCLK = SYSCLK */

  RCC->CFGR |= (blt_int32u)RCC_CFGR_HPRE_DIV1;

  /* PCLK2 = HCLK/2 */

  RCC->CFGR |= (blt_int32u)RCC_CFGR_PPRE2_DIV2;

  /* PCLK1 = HCLK/2 */

  RCC->CFGR |= (blt_int32u)RCC_CFGR_PPRE1_DIV2;

  /* reset PLL configuration */

  RCC->CFGR &= (blt_int32u)((blt_int32u)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | \

                                          RCC_CFGR_PLLMULL));

  /* assert that the pll_multiplier is between 2 and 16 */

  ASSERT_CT((BOOT_CPU_SYSTEM_SPEED_KHZ/BOOT_CPU_XTAL_SPEED_KHZ) >= 2);

  ASSERT_CT((BOOT_CPU_SYSTEM_SPEED_KHZ/BOOT_CPU_XTAL_SPEED_KHZ) <= 16);

  /* calculate multiplier value */

  pll_multiplier = BOOT_CPU_SYSTEM_SPEED_KHZ/BOOT_CPU_XTAL_SPEED_KHZ;

  /* convert to register value */

  pll_multiplier = (blt_int32u)((pll_multiplier - 2) << 18);

  /* set the PLL multiplier and clock source */

  RCC->CFGR |= (blt_int32u)(RCC_CFGR_PLLSRC_HSE | pll_multiplier);

  /* enable PLL */

  RCC->CR |= RCC_CR_PLLON;

  /* wait till PLL is ready */

  while((RCC->CR & RCC_CR_PLLRDY) == 0)

  {

  }

  /* select PLL as system clock source */

  RCC->CFGR &= (blt_int32u)((blt_int32u)~(RCC_CFGR_SW));

  RCC->CFGR |= (blt_int32u)RCC_CFGR_SW_PLL;

  /* wait till PLL is used as system clock source */

  while ((RCC->CFGR & (blt_int32u)RCC_CFGR_SWS) != (blt_int32u)0x08)

  {

  }

#if (BOOT_COM_CAN_ENABLE > 0 || BOOT_GATE_CAN_ENABLE > 0)

  /* enable clocks for CAN transmitter and receiver pins (GPIOB and AFIO) */

  RCC->APB2ENR |= (blt_int32u)(0x00000004 | 0x00000001);

  /* configure CAN Rx (GPIOA11) as alternate function input */

  /* first reset the configuration */

  GPIOA->CRH &= ~(blt_int32u)((blt_int32u)0xf << 12);

  /* CNF8[1:0] = %01 and MODE8[1:0] = %00 */

  GPIOA->CRH |= (blt_int32u)((blt_int32u)0x4 << 12);

  /* configure CAN Tx (GPIOA12) as alternate function push-pull */

  /* first reset the configuration */

  GPIOA->CRH &= ~(blt_int32u)((blt_int32u)0xf << 16);

  /* CNF9[1:0] = %11 and MODE9[1:0] = %11 */

  GPIOA->CRH |= (blt_int32u)((blt_int32u)0xb << 16);

  /* remap CAN1 pins to PortA */

  AFIO->MAPR &= ~(blt_int32u)((blt_int32u)0x3 << 13);

  AFIO->MAPR |=  (blt_int32u)((blt_int32u)0x0 << 13);

  /* enable clocks for CAN controller peripheral */

  RCC->APB1ENR |= (blt_int32u)0x02000000;

#endif

#if (BOOT_COM_UART_ENABLE > 0 || BOOT_GATE_UART_ENABLE > 0)

  /* enable clocks for USART1 peripheral, transmitter and receiver pins (GPIOA and AFIO) */

  RCC->APB2ENR |= (blt_int32u)(0x00004000 | 0x00000004 | 0x00000001);

  /* configure USART1 Tx (GPIOA9) as alternate function push-pull */

  /* first reset the configuration */

  GPIOA->CRH &= ~(blt_int32u)((blt_int32u)0xf << 4);

  /* CNF2[1:0] = %10 and MODE2[1:0] = %11 */

  GPIOA->CRH |= (blt_int32u)((blt_int32u)0xb << 4);

  /* configure USART1 Rx (GPIOA10) as alternate function input floating */

  /* first reset the configuration */

  GPIOA->CRH &= ~(blt_int32u)((blt_int32u)0xf << 8);

  /* CNF2[1:0] = %01 and MODE2[1:0] = %00 */

  GPIOA->CRH |= (blt_int32u)((blt_int32u)0x4 << 8);

#if (BOOT_DEBUGGING_UART2_ENABLE > 0)

  /* enable clocks for USART2 peripheral */

  RCC->APB1ENR |= (blt_int32u)(0x00020000);

  /* configure USART2 Tx (GPIOA2) as alternate function push-pull */

  /* first reset the configuration */

  GPIOA->CRL &= ~(blt_int32u)((blt_int32u)0xf << 8);

  /* CNF2[1:0] = %10 and MODE2[1:0] = %11 */

  GPIOA->CRL |= (blt_int32u)((blt_int32u)0xb << 8);

  /* configure USART2 Rx (GPIOA3) as alternate function input floating */

  /* first reset the configuration */

  GPIOA->CRL &= ~(blt_int32u)((blt_int32u)0xf << 12);

  /* CNF2[1:0] = %01 and MODE2[1:0] = %00 */

  GPIOA->CRL |= (blt_int32u)((blt_int32u)0x4 << 12);

#endif

#elif (BOOT_FILE_LOGGING_ENABLE > 0)

  /* enable UART peripheral clock */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

  /* enable GPIO peripheral clock for transmitter and receiver pins */

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);

  /* configure USART Tx as alternate function push-pull */

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_2;

  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* Configure USART Rx as alternate function input floating */

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN_FLOATING;

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_3;

  GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* configure UART communcation parameters */

  USART_InitStruct.USART_BaudRate = BOOT_COM_UART_BAUDRATE;

  USART_InitStruct.USART_WordLength = USART_WordLength_8b;

  USART_InitStruct.USART_StopBits = USART_StopBits_1;

  USART_InitStruct.USART_Parity = USART_Parity_No;

  USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

  USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

  USART_Init(USART2, &USART_InitStruct);

  /* enable UART */

  USART_Cmd(USART2, ENABLE);

#endif

} /*** end of Init ***/

/*

 * Initializes all GPIO used by the bootloader

 */

static void initGpio() {

  GPIO_InitTypeDef gpio_init;

  /*

   * OUTPUTS

   */

  /* initialize the pseudo LED and push it up (inactive) */

  GPIO_SetBits(PSEUDO_LED_GPIO, PSEUDO_LED_PIN);

  gpio_init.GPIO_Pin    = PSEUDO_LED_PIN;

  gpio_init.GPIO_Mode   = GPIO_Mode_Out_PP;

  gpio_init.GPIO_Speed  = GPIO_Speed_50MHz;

  GPIO_Init(PSEUDO_LED_GPIO, &gpio_init);

  /* initialize SYS_PD_N and let it go (inactive) */

  GPIO_SetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  gpio_init.GPIO_Pin    = SYS_PD_N_PIN;

  gpio_init.GPIO_Mode   = GPIO_Mode_Out_OD;

  gpio_init.GPIO_Speed  = GPIO_Speed_50MHz;

  GPIO_Init(SYS_PD_N_GPIO, &gpio_init);

  /* initialize SYS_SYNC_N and pull it down (active) */

  GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  gpio_init.GPIO_Pin    = SYS_SYNC_N_PIN;

  gpio_init.GPIO_Mode   = GPIO_Mode_Out_OD;

  gpio_init.GPIO_Speed  = GPIO_Speed_50MHz;

  GPIO_Init(SYS_SYNC_N_GPIO, &gpio_init);

  /*

   * INPUTS

   */

} /*** end of initGpio ***/

/*

 * Initialize all EXTI lines

 */

static void initExti() {

  /* configure EXTI lines */

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOD, GPIO_PinSource2); // SYS_SYNC_N

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource5); // LASER_OC_N

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource6); // SYS_UART_DN

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource8); // WL_GDO2

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource9); // WL_GDO0

  GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource14); // SYS_PD_N

  return;

} /*** end of initExti ***/

/*

 * Signals, which type of low-power mode the system shall enter after the shutdown sequence.

 */

ErrorStatus shutdownDisambiguationProcedure(const uint8_t type) {

  GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  ErrorStatus ret_val = ERROR;

  switch (type) {

    case BL_SHUTDOWN_PRI_RSN_UNKNOWN:

    case BL_SHUTDOWN_PRI_RSN_HIBERNATE:

    case BL_SHUTDOWN_PRI_RSN_DEEPSLEEP:

    case BL_SHUTDOWN_PRI_RSN_TRANSPORT:

    {

      // broadcast a number of pulses, depending on the argument

      uint8_t pulse_counter = 0;

      for (pulse_counter = 0; pulse_counter < type; ++pulse_counter) {

        msleep(1);

        GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

        msleep(1);

        GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

      }

      // wait for timeout

      msleep(10);

      ret_val = SUCCESS;

      break;

    }

    case BL_SHUTDOWN_PRI_RSN_RESTART:

    {

      // since there is no ambiguity for restart requests, no pulses are generated

      msleep(10);

      ret_val = SUCCESS;

      break;

    }

    default:

      ret_val = ERROR;

      break;

  }

  return ret_val;

} /*** end of shutdownDisambiguationProcedure ***/

/*

 * Final shutdown of the system to enter transportation mode.

 */

void shutdownToTransportation(const blt_bool exec_disambiguation) {

  /* configure some criticpal GPIOs as input

   * This is required, because otherwise some hardware might be powered through these signals */

  configGpioForShutdown();

  /* wait for all boards to be ready for shutdown */

  GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  // this must no be skipped, since the pull-up voltage for SYS_SYNC_N (VIO3.3) must be configured at this point by definition.

  setLed(BLT_TRUE);

  waitForSignal(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_SET);

  setLed(BLT_FALSE);

  if (exec_disambiguation == BLT_TRUE) {

    /* execute disambiguation procedure and signal all modules to enter transportation mode */

    if (shutdownDisambiguationProcedure(BL_SHUTDOWN_PRI_RSN_TRANSPORT) != SUCCESS) {

      blinkSOS(1);

      msleep(10);

    }

  }

  /* morse 'OK' via the LED to signal that shutdown was successful */

  blinkOK(1);

  /* enter standby mode */

  PWR_EnterSTANDBYMode();

  return;

} /*** end of shutdownToTransportation ***/

/*

 * Final shutdown of the system to enter deepsleep mode.

 */

void shutdownToDeepsleep(const blt_bool exec_disambiguation) {

  /* configure some criticpal GPIOs as input

   * This is required, because otherwise some hardware might be powered through these signals */

  configGpioForShutdown();

  /* wait for all boards to be ready for shutdown */

  GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  // this must no be skipped, since the pull-up voltage for SYS_SYNC_N (VIO3.3) must be configured at this point by definition.

  setLed(BLT_TRUE);

  waitForSignal(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_SET);

  setLed(BLT_FALSE);

  if (exec_disambiguation == BLT_TRUE) {

    /* execute disambiguation procedure and signal all modules to enter deepsleep mode */

    if (shutdownDisambiguationProcedure(BL_SHUTDOWN_PRI_RSN_DEEPSLEEP) != SUCCESS) {

      blinkSOS(1);

      msleep(10);

    }

  }

  /* morse 'OK' via the LED to signal that shutdown was successful */

  blinkOK(1);

  /* enter standby mode */

  PWR_EnterSTANDBYMode();

  return;

} /*** end of shutdownToDeepsleep ***/

/*

 * Final shutdown of the system to enter hibernate mode.

 */

void shutdownToHibernate(const blt_bool exec_disambiguation) {

  /* configure some criticpal GPIOs as input

   * This is required, because otherwise some hardware might be powered through these signals */

  configGpioForShutdown();

  /* wait for all boards to be ready for shutdown */

  GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  // this must no be skipped, since the pull-up voltage for SYS_SYNC_N (VIO3.3) must be configured at this point by definition.

  setLed(BLT_TRUE);

  waitForSignal(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_SET);

  setLed(BLT_FALSE);

  if (exec_disambiguation == BLT_TRUE) {

    /* execute disambiguation procedure and signal all modules to enter hibernate mode */

    if (shutdownDisambiguationProcedure(BL_SHUTDOWN_PRI_RSN_HIBERNATE) != SUCCESS) {

      blinkSOS(1);

      msleep(10);

    }

  }

  /* morse 'OK' via the LED to signal that shutdown was successful */

  blinkOK(1);

  /* enter standby mode */

  PWR_EnterSTANDBYMode();

  return;

} /*** end of shutdownToHibernate ***/

void shutdownAndRestart(const blt_bool exec_disambiguation) {

  /* configure some criticpal GPIOs as input

   * This is required, because otherwise some hardware might be powered through these signals */

  configGpioForShutdown();

  /* wait for all boards to be ready for shutdown */

  GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  // this must no be skipped, since the pull-up voltage for SYS_SYNC_N (VIO3.3) must be configured at this point by definition.

  setLed(BLT_TRUE);

  waitForSignal(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_SET);

  setLed(BLT_FALSE);

  if (exec_disambiguation == BLT_TRUE) {

    /* execute disambiguation procedure and signal all modules to restart in default mode */

    if (shutdownDisambiguationProcedure(BL_SHUTDOWN_PRI_RSN_RESTART) != SUCCESS) {

      blinkSOS(1);

      msleep(10);

    }

  }

  /* morse 'OK' via the LED to signal that shutdown was successful */

  blinkOK(1);

  /* enter standby mode */

  PWR_EnterSTANDBYMode();

  /*

   * Even though this module will not restart the system by its own, the PowerManagement will reset the system.

   */

  return;

} /*** end of shutdownAndRestart***/

/*

 * Configures some GPIO pins as inputs for safety reasons.

 * Under certain circumstances, these pins might power hardware that is supposed to be shut down.

 */

void configGpioForShutdown() {

  /* setup the configuration */

  GPIO_InitTypeDef gpio_init;

  gpio_init.GPIO_Mode   = GPIO_Mode_IN_FLOATING;

  gpio_init.GPIO_Speed  = GPIO_Speed_50MHz;

  /* configure SYS_UART_TX */

  gpio_init.GPIO_Pin = SYS_UART_TX_PIN;

  GPIO_Init(SYS_UART_TX_GPIO, &gpio_init);

  /* configure CAN_TX */

  gpio_init.GPIO_Pin = CAN_TX_PIN;

  GPIO_Init(CAN_TX_GPIO, &gpio_init);

  /* configure all LASER signals */

  gpio_init.GPIO_Pin = LASER_EN_PIN;

  GPIO_Init(LASER_EN_GPIO, &gpio_init);

  gpio_init.GPIO_Pin = LASER_TX_PIN;

  GPIO_Init(LASER_TX_GPIO, &gpio_init);

  /* configure all LIGHT (SPI) signals */

  gpio_init.GPIO_Pin = LIGHT_SCLK_PIN;

  GPIO_Init(LIGHT_SCLK_GPIO, &gpio_init);

  gpio_init.GPIO_Pin = LIGHT_MOSI_PIN;

  GPIO_Init(LIGHT_MOSI_GPIO, &gpio_init);

  gpio_init.GPIO_Pin = LIGHT_XLAT_PIN;

  GPIO_Init(LIGHT_XLAT_GPIO, &gpio_init);

  gpio_init.GPIO_Pin = LIGHT_BLANK_PIN;

  GPIO_Init(LIGHT_BLANK_GPIO, &gpio_init);

  /* configure all WL (SPI) signals */

  gpio_init.GPIO_Pin = WL_SS_N_PIN;

  GPIO_Init(WL_SS_N_GPIO, &gpio_init);

  gpio_init.GPIO_Pin = WL_SCLK_PIN;

  GPIO_Init(WL_SCLK_GPIO, &gpio_init);

  gpio_init.GPIO_Pin = WL_MOSI_PIN;

  GPIO_Init(WL_MOSI_GPIO, &gpio_init);

  return;

} /*** end of configGpioForShutdown ***/

/*

 * System was reset via the NRST pin or the reason could not be detected.

 * In this case, the system enters the boot loop and starts the OS.

 */

ErrorStatus handleWarmReset() {

  /* initialize the bootloader */

  BootInit();

  /* start the infinite program loop */

  uint32_t loopStartTime = 0;

  saTimerUpdate(&loopStartTime);

  uint32_t currentTime = loopStartTime;

  while (1)

  {

//    /* make the pseudo LED "double-blink" */

//    saTimerUpdate(&currentTime);

//    if (currentTime < loopStartTime + 50) {

//      setLed(BLT_TRUE);

//    } else if (currentTime < loopStartTime + 50+100) {

//      setLed(BLT_FALSE);

//    } else if (currentTime < loopStartTime + 50+100+50) {

//      setLed(BLT_TRUE);

//    } else if ( currentTime < loopStartTime + 50+100+50+300) {

//      setLed(BLT_FALSE);

//    } else {

//      loopStartTime = currentTime;

//    }

    /* run the bootloader task */

    BootTask();

    /* check the SYS_PD_N signal */

    if (GPIO_ReadInputDataBit(SYS_PD_N_GPIO, SYS_PD_N_PIN) == Bit_RESET) {

      blCallbackHandleShutdownRequest();

      return SUCCESS;

    }

  }

  return ERROR;

} /*** end of handleWarmReset ***/

/*

 * Callback function that handles the system shutdown and enters transportation mode.

 * When called from a multithreaded environment, it must be ensured that no other thread will preempt this function.

 * In transportation low-power mode the system can only be woken up by pulling down the NRST signal.

 * Furthermore, the system can not be charged when in transportation mode.

 */

void blCallbackShutdownTransportation() {

  /* make sure that the required clocks are activated */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD, ENABLE);

  /* set/keep the SYS_SYNC and SYS_PD signals active */

  GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  GPIO_ResetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  saTimerInit();

  setLed(BLT_TRUE);

  shutdownToTransportation(BLT_TRUE);

  return;

} /*** end of blCallbackShutdownTransportation ***/

/*

 * Callback function that handles the system shutdown and enters deepsleep mode.

 * When called from a multithreaded environment, it must be ensured that no other thread will preempt this function.

 * In deepsleep low-power mode the system can only be woken up via the NRST or the WKUP signal, or the RTC or IWDG, if configured.

 */

void blCallbackShutdownDeepsleep(void) {

  /* make sure that the required clocks are activated */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD, ENABLE);

  /* set/keep the SYS_SYNC and SYS_PD signals active */

  GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  GPIO_ResetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  saTimerInit();

  setLed(BLT_TRUE);

  shutdownToDeepsleep(BLT_TRUE);

  return;

} /*** end of blCallbackShutdownDeepsleep ***/

/*

 * Callback function that handles the system shutdown and enters hibernate mode.

 * When called from a multithreaded environment, it must be ensured that no other thread will preempt this function.

 */

void blCallbackShutdownHibernate(void) {

  /* make sure that the required clocks are activated */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD, ENABLE);

  /* set/keep the SYS_SYNC and SYS_PD signals active */

  GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  GPIO_ResetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  saTimerInit();

  setLed(BLT_TRUE);

  shutdownToHibernate(BLT_TRUE);

  return;

} /*** end of blCallbackShutdownHibernate ***/

/*

 * Callback function that handles the system shutdown and initializes a restart.

 * When called from a multithreaded environment, it must be ensured that no other thread will preempt this function.

 */

void blCallbackShutdownRestart(void) {

  /* make sure that the required clocks are activated */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD, ENABLE);

  /* set/keep the SYS_SYNC and SYS_PD signals active */

  GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  GPIO_ResetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  /* ensure that all modules had a chance to detect the pulse on SYS_PD_N */

  saTimerInit();

  msleep(1);

  GPIO_SetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  msleep(1);

  shutdownAndRestart(BLT_TRUE);

  return;

} /** end of blCallbackShutdownRestart ***/

/*

 * Callback function that handles a system shutdown/restart request from another module.

 * Depending on the result of the disambiguation procedure, the module will enter the according low-power mode or restart.

 * When called from a multithreaded environment, it must be ensured that no other thread will preempt this function.

 */

void blCallbackHandleShutdownRequest(void) {

  /* make sure that the required clocks are activated */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD, ENABLE);

  /* set/keep the SYS_SYNC and SYS_PD signals active */

  GPIO_ResetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  GPIO_ResetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  /* ensure that all modules had a chance to detect the pulse on SYS_PD_N */

  saTimerInit();

  msleep(1);

  GPIO_SetBits(SYS_PD_N_GPIO, SYS_PD_N_PIN);

  msleep(1);

  /* wait for all boards to be ready for shutdown */

  GPIO_SetBits(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN);

  // this must not be skipped, since the pull-up voltage for SYS_SYNC_N (VIO3.3) must be configured at this point by definition.

  setLed(BLT_TRUE);

  waitForSignal(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_SET);

  setLed(BLT_FALSE);

  /* check ths SYS_PD_N signal, whether the system shall shutdown or restart */

  blt_bool shutdown_nrestart = (GPIO_ReadInputDataBit(SYS_PD_N_GPIO, SYS_PD_N_PIN) == Bit_RESET) ? BLT_TRUE : BLT_FALSE;

  /* disambiguation procedure (passive) */

  uint32_t pulse_counter = 0;

  while (waitForSignalTimeout(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_RESET, 10)) {

    waitForSignal(SYS_SYNC_N_GPIO, SYS_SYNC_N_PIN, Bit_SET);

    ++pulse_counter;

  }

  /* evaluate and hanlde disambiguation result */

  if (shutdown_nrestart == BLT_TRUE) {

    /* shutdown request */

    /* handle special cases */

    if (pulse_counter == BL_SHUTDOWN_PRI_RSN_UNKNOWN) {

      /* no pulse at all was received */

      pulse_counter = BL_SHUTDOWN_PRI_RSN_DEFAULT;

    } else if (pulse_counter != BL_SHUTDOWN_PRI_RSN_HIBERNATE &&

               pulse_counter != BL_SHUTDOWN_PRI_RSN_DEEPSLEEP &&

               pulse_counter != BL_SHUTDOWN_PRI_RSN_TRANSPORT) {

      /* invalid number of pulses received */

      blinkSOS(1);

      pulse_counter = BL_SHUTDOWN_PRI_RSN_DEFAULT;

    }

    switch (pulse_counter) {

      case BL_SHUTDOWN_PRI_RSN_HIBERNATE:

        shutdownToHibernate(BLT_FALSE);

        break;

      case BL_SHUTDOWN_PRI_RSN_DEEPSLEEP:

        shutdownToDeepsleep(BLT_FALSE);

        break;

      case BL_SHUTDOWN_PRI_RSN_TRANSPORT:

        shutdownToTransportation(BLT_FALSE);

        break;

    }

  } else {

    /* restart request */

    /* there is no ambiguity for restart, so it is ignored */

    shutdownAndRestart(BLT_FALSE);

  }

  /* if this code is reached, the system did neither shut down, nor restart.

   * This must never be the case!

   */

  blinkSOSinf();

  return;

} /*** end of blCallbackHandleShutdownRequest ***/

/*********************************** end of main.c *************************************/