AMiRo-OS

/*

AMiRo-OS is an operating system designed for the Autonomous Mini Robot (AMiRo) platform.

Copyright (C) 2016..2018  Thomas Schöpping et al.

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/>.

*/

#include <aos_system.h>

#include <chprintf.h>

#include <amiroos.h>

#include <amiroblt.h>

#include <string.h>

#include <stdarg.h>

#if (AMIROOS_CFG_TESTS_ENABLE == true)

#include <ch_test.h>

#endif

/**

 * @brief   Period of the system timer.

 */

#define SYSTIMER_PERIOD               (TIME_MAXIMUM - CH_CFG_ST_TIMEDELTA)

/**

 * @brief   Width of the printable system info text.

 */

#define SYSTEM_INFO_WIDTH             70

/**

 * @brief   Width of the name column of the system info table.

 */

#define SYSTEM_INFO_NAMEWIDTH         14

/* forward declarations */

static void _printSystemInfo(BaseSequentialStream* stream);

#if (AMIROOS_CFG_SHELL_ENABLE == true)

static int _shellcmd_configcb(BaseSequentialStream* stream, int argc, char* argv[]);

static int _shellcmd_infocb(BaseSequentialStream* stream, int argc, char* argv[]);

static int _shellcmd_shutdowncb(BaseSequentialStream* stream, int argc, char* argv[]);

#endif /* AMIROOS_CFG_SHELL_ENABLE == true */

#if (AMIROOS_CFG_TESTS_ENABLE == true)

static int _shellcmd_kerneltestcb(BaseSequentialStream* stream, int argc, char* argv[]);

#endif /* AMIROOS_CFG_TESTS_ENABLE == true */

/**

 * @brief   PD signal GPIO.

 */

static apalControlGpio_t* _gpioPd;

/**

 * @brief   Sync signal GPIO.

 */

static apalControlGpio_t* _gpioSync;

/**

 * @brief   Timer to accumulate system uptime.

 */

static virtual_timer_t _systimer;

/**

 * @brief   Accumulated system uptime.

 */

static aos_timestamp_t _uptime;

/**

 * @brief   Timer register value of last accumulation.

 */

static systime_t _synctime;

#if (AMIROOS_CFG_SSSP_MASTER == true) || defined(__DOXYGEN__)

/**

 * @brief   Timer to drive the SYS_SYNC signal for system wide time synchronization according to SSSP.

 */

static virtual_timer_t _syssynctimer;

/**

 * @brief   Last uptime of system wide time synchronization.

 */

static aos_timestamp_t _syssynctime;

#endif

#if (AMIROOS_CFG_SHELL_ENABLE == true) || defined(__DOXYGEN__)

/**

 * @brief   System shell.

 */

static aos_shell_t _shell;

/**

 * @brief   Shell thread working area.

 */

THD_WORKING_AREA(_shell_wa, AMIROOS_CFG_SHELL_STACKSIZE);

/**

 * @brief   Shell input buffer.

 */

static char _shell_line[AMIROOS_CFG_SHELL_LINEWIDTH];

/**

 * @brief   Shell argument buffer.

 */

static char* _shell_arglist[AMIROOS_CFG_SHELL_MAXARGS];

/**

 * @brief   Shell command to retrieve system information.

 */

static aos_shellcommand_t _shellcmd_info = {

  /* name     */ "module:info",

  /* callback */ _shellcmd_infocb,

  /* next     */ NULL,

};

/**

 * @brief   Shell command to set or retrieve system configuration.

 */

static aos_shellcommand_t _shellcmd_config = {

  /* name     */ "module:config",

  /* callback */ _shellcmd_configcb,

  /* next     */ NULL,

};

/**

 * @brief   Shell command to shutdown the system.

 */

static aos_shellcommand_t _shellcmd_shutdown = {

  /* name     */ "system:shutdown",

  /* callback */ _shellcmd_shutdowncb,

  /* next     */ NULL,

};

#endif /* AMIROOS_CFG_SHELL_ENABLE == true */

#if (AMIROOS_CFG_TESTS_ENABLE == true) || defined(__DOXYGEN__)

/**

 * @brief   Shell kommand to run a test of the ChibiOS/RT kernel.

 */

static aos_shellcommand_t _shellcmd_kerneltest = {

  /* name     */ "kernel:test",

  /* callback */ _shellcmd_kerneltestcb,

  /* next     */ NULL,

};

#endif /* AMIROOS_CFG_TESTS_ENABLE == true */

/**

 * @brief   Global system object.

 */

aos_system_t aos = {

  /* SSSP stage       */ AOS_SSSP_STARTUP_2_1,

  /* I/O stream       */ {

    /* channel          */ NULL,

  },

  /* event            */ {

    /* I/O              */ {

      /* source           */ {

        /* next listener    */ NULL,

      },

      /* flagsSignalPd    */ 0,

      /* flagsSignalSync  */ 0,

    },

    /* OS               */ {

      /* source           */ {

        /* next listener    */ NULL,

      }

    },

  },

#if (AMIROOS_CFG_SHELL_ENABLE == true)

  /* shell            */ &_shell,

#endif

};

/**

 * @brief   Print a separator line.

 *

 * @param[in] stream    Stream to print to or NULL to print to all system streams.

 * @param[in] c         Character to use.

 * @param[in] n         Length of the separator line.

 *

 * @return  Number of characters printed.

 */

static unsigned int _printSystemInfoSeparator(BaseSequentialStream* stream, const char c, const unsigned int n)

{

  aosDbgCheck(stream != NULL);

  // print the specified character n times

  for (unsigned int i = 0; i < n; ++i) {

    streamPut(stream, c);

  }

  streamPut(stream, '\n');

  return n+1;

}

/**

 * @brief   Print a system information line.

 * @details Prints a system information line with the following format:

 *            "<name>[spaces]fmt"

 *          The combined width of "<name>[spaces]" can be specified in order to align <fmt> on multiple lines.

 *          Note that there is not trailing newline added implicitely.

 *

 * @param[in] stream      Stream to print to or NULL to print to all system streams.

 * @param[in] name        Name of the entry/line.

 * @param[in] namewidth   Width of the name column.

 * @param[in] fmt         Formatted string of information content.

 *

 * @return  Number of characters printed.

 */

static unsigned int _printSystemInfoLine(BaseSequentialStream* stream, const char* name, const unsigned int namewidth, const char* fmt, ...)

{

  aosDbgCheck(stream != NULL);

  aosDbgCheck(name != NULL);

  unsigned int n = 0;

  va_list ap;

  va_start(ap, fmt);

  n += chprintf(stream, name);

  while (n < namewidth) {

    streamPut(stream, ' ');

    ++n;

  }

  n += chvprintf(stream, fmt, ap);

  va_end(ap);

  return n;

}

/**

 * @brief   Prints information about the system.

 *

 * @param[in] stream    Stream to print to.

 */

static void _printSystemInfo(BaseSequentialStream* stream)

{

  aosDbgCheck(stream != NULL);

  _printSystemInfoSeparator(stream, '=', SYSTEM_INFO_WIDTH);

  _printSystemInfoLine(stream, "Module", SYSTEM_INFO_NAMEWIDTH, "%s (v%s)\n", BOARD_NAME, BOARD_VERSION);

#ifdef PLATFORM_NAME

  _printSystemInfoLine(stream, "Platform", SYSTEM_INFO_NAMEWIDTH, "%s\n", PLATFORM_NAME);

#endif

#ifdef PORT_CORE_VARIANT_NAME

  _printSystemInfoLine(stream, "Core Variant", SYSTEM_INFO_NAMEWIDTH, "%s\n", PORT_CORE_VARIANT_NAME);

#endif

  _printSystemInfoLine(stream, "Architecture", SYSTEM_INFO_NAMEWIDTH, "%s\n", PORT_ARCHITECTURE_NAME);

  _printSystemInfoSeparator(stream, '-', SYSTEM_INFO_WIDTH);

  _printSystemInfoLine(stream, "AMiRo-OS" ,SYSTEM_INFO_NAMEWIDTH, "%u.%u.%u %s (SSSP %u.%u)\n", AMIROOS_VERSION_MAJOR, AMIROOS_VERSION_MINOR, AMIROOS_VERSION_PATCH, AMIROOS_RELEASE_TYPE, AOS_SYSTEM_SSSP_MAJOR, AOS_SYSTEM_SSSP_MINOR);

  _printSystemInfoLine(stream, "AMiRo-LLD" ,SYSTEM_INFO_NAMEWIDTH, "%u.%u.%u %s (periphAL %u.%u)\n", AMIRO_LLD_VERSION_MAJOR, AMIRO_LLD_VERSION_MINOR, AMIRO_LLD_VERSION_PATCH, AMIRO_LLD_RELEASE_TYPE, PERIPHAL_VERSION_MAJOR, PERIPHAL_VERSION_MINOR);

  _printSystemInfoLine(stream, "ChibiOS/RT" ,SYSTEM_INFO_NAMEWIDTH, "%u.%u.%u %s\n", CH_KERNEL_MAJOR, CH_KERNEL_MINOR, CH_KERNEL_PATCH, (CH_KERNEL_STABLE == 1) ? "stable" : "non-stable");

  _printSystemInfoLine(stream, "ChibiOS/HAL",SYSTEM_INFO_NAMEWIDTH, "%u.%u.%u %s\n", CH_HAL_MAJOR, CH_HAL_MINOR, CH_HAL_PATCH, (CH_HAL_STABLE == 1) ? "stable" : "non-stable");

  _printSystemInfoLine(stream, "build type",SYSTEM_INFO_NAMEWIDTH,"%s\n", (AMIROOS_CFG_DBG == true) ? "debug" : "release");

  _printSystemInfoLine(stream, "Compiler" ,SYSTEM_INFO_NAMEWIDTH, "%s %u.%u.%u\n", "GCC", __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__); // TODO: support other compilers than GCC

  _printSystemInfoLine(stream, "Compiled" ,SYSTEM_INFO_NAMEWIDTH, "%s - %s\n", __DATE__, __TIME__);

  _printSystemInfoSeparator(stream, '-', SYSTEM_INFO_WIDTH);

  if (BL_CALLBACK_TABLE_ADDRESS->magicNumber == BL_MAGIC_NUMBER) {

    _printSystemInfoLine(stream, "AMiRo-BLT", SYSTEM_INFO_NAMEWIDTH, "%u.%u.%u %s (SSSP %u.%u)\n", BL_CALLBACK_TABLE_ADDRESS->vBootloader.major, BL_CALLBACK_TABLE_ADDRESS->vBootloader.minor, BL_CALLBACK_TABLE_ADDRESS->vBootloader.patch,

                         (BL_CALLBACK_TABLE_ADDRESS->vBootloader.identifier == BL_VERSION_ID_AMiRoBLT_Release) ? "stable" :

                         (BL_CALLBACK_TABLE_ADDRESS->vBootloader.identifier == BL_VERSION_ID_AMiRoBLT_ReleaseCandidate) ? "release candidate" :

                         (BL_CALLBACK_TABLE_ADDRESS->vBootloader.identifier == BL_VERSION_ID_AMiRoBLT_Beta) ? "beta" :

                         (BL_CALLBACK_TABLE_ADDRESS->vBootloader.identifier == BL_VERSION_ID_AMiRoBLT_Alpha) ? "alpha" :

                         (BL_CALLBACK_TABLE_ADDRESS->vBootloader.identifier == BL_VERSION_ID_AMiRoBLT_PreAlpha) ? "pre-alpha" :

                         "<release type unknown>",

                         BL_CALLBACK_TABLE_ADDRESS->vSSSP.major, BL_CALLBACK_TABLE_ADDRESS->vSSSP.minor);

    if (BL_CALLBACK_TABLE_ADDRESS->vSSSP.major != AOS_SYSTEM_SSSP_MAJOR) {

      if (stream) {

        chprintf(stream, "WARNING: Bootloader and AMiRo-OS implement incompatible SSSP versions!\n");

      } else {

        aosprintf("WARNING: Bootloader and AMiRo-OS implement incompatible SSSP versions!\n");

      }

    }

    _printSystemInfoLine(stream, "Compiler", SYSTEM_INFO_NAMEWIDTH, "%s %u.%u.%u\n", (BL_CALLBACK_TABLE_ADDRESS->vCompiler.identifier == BL_VERSION_ID_GCC) ? "GCC" : "<compiler unknown>", BL_CALLBACK_TABLE_ADDRESS->vCompiler.major, BL_CALLBACK_TABLE_ADDRESS->vCompiler.minor, BL_CALLBACK_TABLE_ADDRESS->vCompiler.patch); // TODO: support other compilers than GCC

  } else {

    if (stream) {

      chprintf(stream, "Bootloader incompatible or not available.\n");

    } else {

      aosprintf("Bootloader incompatible or not available.\n");

    }

  }

  _printSystemInfoSeparator(stream, '=', SYSTEM_INFO_WIDTH);

  return;

}

#if (AMIROOS_CFG_SHELL_ENABLE == true) || defined(__DOXYGEN__)

/**

 * @brief   Callback function for the system:config shell command.

 *

 * @param[in] stream    The I/O stream to use.

 * @param[in] argc      Number of arguments.

 * @param[in] argv      List of pointers to the arguments.

 *

 * @return              An exit status.

 * @retval  AOS_OK                  The command was executed successfuly.

 * @retval  AOS_INVALID_ARGUMENTS   There was an issue with the arguemnts.

 */

static int _shellcmd_configcb(BaseSequentialStream* stream, int argc, char* argv[])

{

  aosDbgCheck(stream != NULL);

  // local variables

  int retval = AOS_INVALID_ARGUMENTS;

  // if there are additional arguments

  if (argc > 1) {

    // if the user wants to set or retrieve the shell configuration

    if (strcmp(argv[1], "--shell") == 0) {

      // if the user wants to modify the shell configuration

      if (argc > 2) {

        // if the user wants to modify the prompt

        if (strcmp(argv[2], "prompt") == 0) {

          // there must be a further argument

          if (argc > 3) {

            // handle the option

            if (strcmp(argv[3], "text") == 0) {

              aos.shell->config &= ~AOS_SHELL_CONFIG_PROMPT_MINIMAL;

              retval = AOS_OK;

            }

            else if (strcmp(argv[3], "minimal") == 0) {

              aos.shell->config |= AOS_SHELL_CONFIG_PROMPT_MINIMAL;

              retval = AOS_OK;

            }

            else if (strcmp(argv[3], "notime") == 0) {

              aos.shell->config &= ~AOS_SHELL_CONFIG_PROMPT_UPTIME;

              retval = AOS_OK;

            }

            else if (strcmp(argv[3], "uptime") == 0) {

              aos.shell->config |= AOS_SHELL_CONFIG_PROMPT_UPTIME;

              retval = AOS_OK;

            }

          }

        }

        // if the user wants to modify the string matching

        else if (strcmp(argv[2], "match") == 0) {

          // there must be a further argument

          if (argc > 3) {

            if (strcmp(argv[3], "casesensitive") == 0) {

              aos.shell->config |= AOS_SHELL_CONFIG_MATCH_CASE;

              retval = AOS_OK;

            }

            else if (strcmp(argv[3], "caseinsensitive") == 0) {

              aos.shell->config &= ~AOS_SHELL_CONFIG_MATCH_CASE;

              retval = AOS_OK;

            }

          }

        }

      }

      // if the user wants to retrieve the shell configuration

      else {

        chprintf(stream, "current shell configuration:\n");

        chprintf(stream, "  prompt text:   %s\n",

                 (aos.shell->prompt != NULL) ? aos.shell->prompt : "n/a");

        chprintf(stream, "  prompt style:  %s, %s\n",

                 (aos.shell->config & AOS_SHELL_CONFIG_PROMPT_MINIMAL) ? "minimal" : "text",

                 (aos.shell->config & AOS_SHELL_CONFIG_PROMPT_UPTIME) ? "system uptime" : "no time");

        chprintf(stream, "  input method:  %s\n",

                 (aos.shell->config & AOS_SHELL_CONFIG_INPUT_OVERWRITE) ? "replace" : "insert");

        chprintf(stream, "  text matching: %s\n",

                 (aos.shell->config & AOS_SHELL_CONFIG_MATCH_CASE) ? "case sensitive" : "case insensitive");

        retval = AOS_OK;

      }

    }

  }

  // print help, if required

  if (retval == AOS_INVALID_ARGUMENTS) {

    chprintf(stream, "Usage: %s OPTION\n", argv[0]);

    chprintf(stream, "Options:\n");

    chprintf(stream, "  --help\n");

    chprintf(stream, "    Print this help text.\n");

    chprintf(stream, "  --shell [OPT [VAL]]\n");

    chprintf(stream, "    Set or retrieve shell configuration.\n");

    chprintf(stream, "    Possible OPTs and VALs are:\n");

    chprintf(stream, "      prompt text|minimal|uptime|notime\n");

    chprintf(stream, "        Configures the prompt.\n");

    chprintf(stream, "      match casesensitive|caseinsenitive\n");

    chprintf(stream, "        Configures string matching.\n");

  }

  return (argc > 1 && strcmp(argv[1], "--help") == 0) ? AOS_OK : retval;

}

/**

 * @brief   Callback function for the system:info shell command.

 *

 * @param[in] stream    The I/O stream to use.

 * @param[in] argc      Number of arguments.

 * @param[in] argv      List of pointers to the arguments.

 *

 * @return            An exit status.

 * @retval  AOS_OK    The command was executed successfully.

 */

static int _shellcmd_infocb(BaseSequentialStream* stream, int argc, char* argv[])

{

  aosDbgCheck(stream != NULL);

  (void)argc;

  (void)argv;

  // print system information

  _printSystemInfo(stream);

  // print time measurement precision

  chprintf(stream, "system time resolution: %uus\n", AOS_SYSTEM_TIME_RESOLUTION);

  // print system uptime

  aos_timestamp_t uptime;

  aosSysGetUptime(&uptime);

  chprintf(stream, "The system is running for\n");

  chprintf(stream, "%10u days\n", (uint32_t)(uptime / MICROSECONDS_PER_DAY));

  chprintf(stream, "%10u hours\n", (uint8_t)(uptime % MICROSECONDS_PER_DAY / MICROSECONDS_PER_HOUR));

  chprintf(stream, "%10u minutes\n", (uint8_t)(uptime % MICROSECONDS_PER_HOUR / MICROSECONDS_PER_MINUTE));

  chprintf(stream, "%10u seconds\n", (uint8_t)(uptime % MICROSECONDS_PER_MINUTE / MICROSECONDS_PER_SECOND));

  chprintf(stream, "%10u milliseconds\n", (uint16_t)(uptime % MICROSECONDS_PER_SECOND / MICROSECONDS_PER_MILLISECOND));

  chprintf(stream, "%10u microseconds\n", (uint16_t)(uptime % MICROSECONDS_PER_MILLISECOND / MICROSECONDS_PER_MICROSECOND));

  return AOS_OK;

}

/**

 * @brief   Callback function for the sytem:shutdown shell command.

 *

 * @param[in] stream    The I/O stream to use.

 * @param[in] argc      Number of arguments.

 * @param[in] argv      List of pointers to the arguments.

 *

 * @return              An exit status.

 * @retval  AOS_OK                  The command was executed successfully.

 * @retval  AOS_INVALID_ARGUMENTS   There was an issue with the arguments.

 */

static int _shellcmd_shutdowncb(BaseSequentialStream* stream, int argc, char* argv[])

{

  aosDbgCheck(stream != NULL);

  // print help text

  if (argc != 2 || strcmp(argv[1], "--help") == 0) {

    chprintf(stream, "Usage: %s OPTION\n", argv[0]);

    chprintf(stream, "Options:\n");

    chprintf(stream, "  --help\n");

    chprintf(stream, "    Print this help text.\n");

    chprintf(stream, "  --hibernate, -h\n");

    chprintf(stream, "    Shutdown to hibernate mode.\n");

    chprintf(stream, "    Least energy saving, but allows charging via pins.\n");

    chprintf(stream, "  --deepsleep, -d\n");

    chprintf(stream, "    Shutdown to deepsleep mode.\n");

    chprintf(stream, "    Minimum energy consumption while allowing charging via plug.\n");

    chprintf(stream, "  --transportation, -t\n");

    chprintf(stream, "    Shutdown to transportation mode.\n");

    chprintf(stream, "    Minimum energy consumption with all interrupts disabled (no charging).\n");

    chprintf(stream, "  --restart, -r\n");

    chprintf(stream, "    Shutdown and restart system.\n");

    return (argc != 2) ? AOS_INVALID_ARGUMENTS : AOS_OK;

  }

  // handle argument

  else {

    if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "--hibernate") == 0) {

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_HIBERNATE);

      chThdTerminate(currp);

      return AOS_OK;

    }

    else if (strcmp(argv[1], "-d") == 0 || strcmp(argv[1], "--deepsleep") == 0) {

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_DEEPSLEEP);

      chThdTerminate(currp);

      return AOS_OK;

    }

    else if (strcmp(argv[1], "-t") == 0 || strcmp(argv[1], "--transportation") == 0) {

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_TRANSPORTATION);

      chThdTerminate(currp);

      return AOS_OK;

    }

    else if (strcmp(argv[1], "-r") == 0 || strcmp(argv[1], "--restart") == 0) {

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_RESTART);

      chThdTerminate(currp);

      return AOS_OK;

    }

    else {

      chprintf(stream, "unknown argument %s\n", argv[1]);

      return AOS_INVALID_ARGUMENTS;

    }

  }

}

#endif /* AMIROOS_CFG_SHELL_ENABLE == true */

#if (AMIROOS_CFG_TESTS_ENABLE == true) || defined(__DOXYGEN__)

/**

 * @brief   Callback function for the kernel:test shell command.

 *

 * @param[in] stream    The I/O stream to use.

 * @param[in] argc      Number of arguments.

 * @param[in] argv      List of pointers to the arguments.

 *

 * @return      An exit status.

 */

static int _shellcmd_kerneltestcb(BaseSequentialStream* stream, int argc, char* argv[])

{

  aosDbgCheck(stream != NULL);

  (void)argc;

  (void)argv;

  tprio_t prio = chThdGetPriorityX();

  chThdSetPriority(HIGHPRIO - 5); // some tests increase priorirty by 5, so this is the maximum priority permitted

  msg_t retval = test_execute(stream);

  chThdSetPriority(prio);

  return retval;

}

#endif /* AMIROOS_CFG_TESTS_ENABLE == true */

/**

 * @brief   Callback function for the PD signal interrupt.

 *

 * @param[in] extp      Pointer to the interrupt driver object.

 * @param[in] channel   Interrupt channel identifier.

 */

static void _signalPdCallback(EXTDriver* extp, expchannel_t channel)

{

  (void)extp;

  (void)channel;

  chSysLockFromISR();

  chEvtBroadcastFlagsI(&aos.events.io.source, aos.events.io.flagsSignalPd);

  chSysUnlockFromISR();

  return;

}

/**

 * @brief   Callback function for the Sync signal interrupt.

 *

 * @param[in] extp      Pointer to the interrupt driver object.

 * @param[in] channel   Interrupt channel identifier.

 */

static void _signalSyncCallback(EXTDriver* extp, expchannel_t channel)

{

  (void)extp;

  (void)channel;

#if (AMIROOS_CFG_SSSP_MASTER == true)

  chSysLockFromISR();

  chEvtBroadcastFlagsI(&aos.events.io.source, aos.events.io.flagsSignalSync);

  chSysUnlockFromISR();

#else

  apalControlGpioState_t s_state;

  aos_timestamp_t uptime;

  chSysLockFromISR();

  // get current uptime

  aosSysGetUptimeX(&uptime);

  // read signal S

  apalControlGpioGet(_gpioSync, &s_state);

  // if S was toggled from on to off during SSSP operation phase

  if (aos.ssspStage == AOS_SSSP_OPERATION && s_state == APAL_GPIO_OFF) {

    // align the uptime with the synchronization period

    if (uptime % AMIROOS_CFG_SSSP_SYSSYNCPERIOD < AMIROOS_CFG_SSSP_SYSSYNCPERIOD / 2) {

      _uptime -= uptime % AMIROOS_CFG_SSSP_SYSSYNCPERIOD;

    } else {

      _uptime += AMIROOS_CFG_SSSP_SYSSYNCPERIOD - (uptime % AMIROOS_CFG_SSSP_SYSSYNCPERIOD);

    }

  }

  // broadcast event

  chEvtBroadcastFlagsI(&aos.events.io.source, aos.events.io.flagsSignalSync);

  chSysUnlockFromISR();

#endif

  return;

}

/**

 * @brief   Callback function for the uptime accumulation timer.

 *

 * @param[in] par   Generic parameter.

 */

#include <module.h>

static void _uptimeCallback(void* par)

{

  (void)par;

  chSysLockFromISR();

  // read current time in system ticks

  register const systime_t st = chVTGetSystemTimeX();

  // update the uptime variables

  _uptime += LL_ST2US(st - _synctime);

  _synctime = st;

  // enable the timer again

  chVTSetI(&_systimer, SYSTIMER_PERIOD, &_uptimeCallback, NULL);

  chSysUnlockFromISR();

  return;

}

#if (AMIROOS_CFG_SSSP_MASTER == true) || defined (__DOXYGEN__)

/**

 * @brief   Periodic system synchronization callback function.

 * @details Toggles the SYS_SYNC signal and reconfigures the system synchronization timer.

 *

 * @param[in] par   Unuesed parameters.

 */

static void _sysSyncTimerCallback(void* par)

{

  (void)par;

  apalControlGpioState_t s_state;

  aos_timestamp_t uptime;

  chSysLockFromISR();

  // read and toggle signal S

  apalControlGpioGet(_gpioSync, &s_state);

  s_state = (s_state == APAL_GPIO_ON) ? APAL_GPIO_OFF : APAL_GPIO_ON;

  apalControlGpioSet(_gpioSync, s_state);

  // if S was toggled from off to on

  if (s_state == APAL_GPIO_ON) {

    // reconfigure the timer precisely, because the logically falling edge (next interrupt) snychronizes the system time

    _syssynctime += AMIROOS_CFG_SSSP_SYSSYNCPERIOD;

    aosSysGetUptimeX(&uptime);

    chVTSetI(&_syssynctimer, LL_US2ST(_syssynctime - uptime), _sysSyncTimerCallback, NULL);

  }

  // if S was toggled from on to off

  else /* if (s_state == APAL_GPIO_OFF) */ {

    // reconfigure the timer (lazy)

    chVTSetI(&_syssynctimer, LL_US2ST(AMIROOS_CFG_SSSP_SYSSYNCPERIOD / 2), _sysSyncTimerCallback, NULL);

  }

  chSysUnlockFromISR();

  return;

}

#endif

/**

 * @brief   AMiRo-OS system initialization.

 * @note    Must be called from the system control thread (usually main thread).

 *

 * @param[in] extDrv        Pointer to the interrupt driver.

 * @param[in] extCfg        Configuration for the interrupt driver.

 * @param[in] gpioPd        GPIO of the PD signal.

 * @param[in] gpioSync      GPIO of the Sync signal

 * @param[in] evtFlagsPd    Event flags to be set when a PD interrupt occurs.

 * @param[in] evtFlagsSync  Event flags to be set when a Sync interrupt occurs.

 * @param[in] shellPrompt   String to be printed as prompt of the system shell.

 * @param[in] stdio         Default (usually physically) interface for I/O like shell.

 */

void aosSysInit(EXTDriver* extDrv,

                EXTConfig* extCfg,

                apalControlGpio_t* gpioPd,

                apalControlGpio_t* gpioSync,

                eventflags_t evtFlagsPd,

                eventflags_t evtFlagsSync,

                const char* shellPrompt)

{

  // check arguments

  aosDbgCheck(extDrv != NULL);

  aosDbgCheck(extCfg != NULL);

  aosDbgCheck(gpioPd != NULL);

  aosDbgCheck(gpioSync != NULL);

  // set control thread to maximum priority

  chThdSetPriority(THD_CTRLPRIO);

  // set local variables

  _gpioPd = gpioPd;

  _gpioSync = gpioSync;

  chVTObjectInit(&_systimer);

  _synctime = 0;

  _uptime = 0;

#if (AMIROOS_CFG_SSSP_MASTER == true)

  chVTObjectInit(&_syssynctimer);

  _syssynctime = 0;

#endif

  // set aos configuration

  aos.ssspStage = AOS_SSSP_STARTUP_2_1;

  aosIOStreamInit(&aos.iostream);

  chEvtObjectInit(&aos.events.io.source);

  chEvtObjectInit(&aos.events.os.source);

  aos.events.io.flagsSignalPd = evtFlagsPd;

  aos.events.io.flagsSignalSync = evtFlagsSync;

  // setup external interrupt system

  extCfg->channels[gpioPd->gpio->pad].cb = _signalPdCallback;

  extCfg->channels[gpioSync->gpio->pad].cb = _signalSyncCallback;

  extStart(extDrv, extCfg);

#if (AMIROOS_CFG_SHELL_ENABLE == true)

  // init shell

  aosShellInit(aos.shell,

               &aos.events.os.source,

               shellPrompt,

               _shell_line,

               AMIROOS_CFG_SHELL_LINEWIDTH,

               _shell_arglist,

               AMIROOS_CFG_SHELL_MAXARGS);

  // add system commands

  aosShellAddCommand(aos.shell, &_shellcmd_config);

  aosShellAddCommand(aos.shell, &_shellcmd_info);

  aosShellAddCommand(aos.shell, &_shellcmd_shutdown);

#if (AMIROOS_CFG_TESTS_ENABLE == true)

  aosShellAddCommand(aos.shell, &_shellcmd_kerneltest);

#endif

#else

  (void)shellPrompt;

#endif

  return;

}

/**

 * @brief   Starts the system and all system threads.

 */

inline void aosSysStart(void)

{

  // update the system SSSP stage

  aos.ssspStage = AOS_SSSP_OPERATION;

  // print system information;

  _printSystemInfo((BaseSequentialStream*)&aos.iostream);

  aosprintf("\n");

#if (AMIROOS_CFG_SHELL_ENABLE == true)

  // start system shell thread

  aos.shell->thread = chThdCreateStatic(_shell_wa, sizeof(_shell_wa), AMIROOS_CFG_SHELL_THREADPRIO, aosShellThread, aos.shell);

#endif

  return;

}

/**

 * @brief   Implements the SSSP startup synchronization step.

 *

 * @param[in] syncEvtListener   Event listener that receives the Sync event.

 *

 * @return    If another event that the listener is interested in was received, its mask is returned.

 *            Otherwise an empty mask (0) is returned.

 */

eventmask_t aosSysSsspStartupOsInitSyncCheck(event_listener_t* syncEvtListener)

{

  aosDbgCheck(syncEvtListener != NULL);

  // local variables

  eventmask_t m;

  eventflags_t f;

  apalControlGpioState_t s;

  // update the system SSSP stage

  aos.ssspStage = AOS_SSSP_STARTUP_2_2;

  // deactivate the sync signal to indicate that the module is ready (SSSPv1 stage 2.1 of startup phase)

  apalControlGpioSet(_gpioSync, APAL_GPIO_OFF);

  // wait for any event to occur (do not apply any filter in order not to miss any event)

  m = chEvtWaitOne(ALL_EVENTS);

  f = chEvtGetAndClearFlags(syncEvtListener);

  apalControlGpioGet(_gpioSync, &s);

  // if the event was a system event,

  //   and it was fired because of the SysSync control signal,

  //   and the SysSync control signal has been deactivated

  if (m & syncEvtListener->events &&

      f == aos.events.io.flagsSignalSync &&

      s == APAL_GPIO_OFF) {

    chSysLock();

#if (AMIROOS_CFG_SSSP_MASTER == true)

    // start the systen synchronization counter

    chVTSetI(&_syssynctimer, LL_US2ST(AMIROOS_CFG_SSSP_SYSSYNCPERIOD / 2), &_sysSyncTimerCallback, NULL);

#endif

    // start the uptime counter

    _synctime = chVTGetSystemTimeX();

    _uptime = 0;

    chVTSetI(&_systimer, SYSTIMER_PERIOD, &_uptimeCallback, NULL);

    chSysUnlock();

    return 0;

  }

  // an unexpected event occurred

  else {

    // reassign the flags to the event and return the event mask

    syncEvtListener->flags |= f;

    return m;

  }

}

/**

 * @brief   Retrieves the system uptime.

 *

 * @param[out] ut   The system uptime.

 */

inline void aosSysGetUptimeX(aos_timestamp_t* ut)

{

  aosDbgCheck(ut != NULL);

  *ut = _uptime + LL_ST2US(chVTGetSystemTimeX() - _synctime);

  return;

}

/**

 * @brief   Initializes/Acknowledges a system shutdown/restart request.

 * @note    This functions should be called from the thread with highest priority.

 *

 * @param[in] shutdown    Type of shutdown.

 */

void aosSysShutdownInit(aos_shutdown_t shutdown)

{

  // check arguments

  aosDbgCheck(shutdown != AOS_SHUTDOWN_NONE);

#if (AMIROOS_CFG_SSSP_MASTER == true)

  // deactivate the system synchronization timer

  chVTReset(&_syssynctimer);

#endif

  // update the system SSSP stage

  aos.ssspStage = AOS_SSSP_SHUTDOWN_1_1;

  // activate the SYS_PD control signal only, if this module initiated the shutdown

  chSysLock();

  if (shutdown != AOS_SHUTDOWN_PASSIVE) {

    apalControlGpioSet(_gpioPd, APAL_GPIO_ON);

  }

  // activate the SYS_SYNC signal

  apalControlGpioSet(_gpioSync, APAL_GPIO_ON);

  chSysUnlock();

  switch (shutdown) {

    case AOS_SHUTDOWN_PASSIVE:

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_SHUTDOWN);

      aosprintf("shutdown request received...\n");

      break;

    case AOS_SHUTDOWN_HIBERNATE:

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_HIBERNATE);

      aosprintf("shutdown to hibernate mode...\n");

      break;

    case AOS_SHUTDOWN_DEEPSLEEP:

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_DEEPSLEEP);

      aosprintf("shutdown to deepsleep mode...\n");

      break;

    case AOS_SHUTDOWN_TRANSPORTATION:

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_TRANSPORTATION);

      aosprintf("shutdown to transportation mode...\n");

      break;

    case AOS_SHUTDOWN_RESTART:

      chEvtBroadcastFlags(&aos.events.os.source, AOS_SYSTEM_EVENTFLAGS_RESTART);

      aosprintf("restarting system...\n");

      break;

   // must never occur

   case AOS_SHUTDOWN_NONE:

   default:

      break;

  }

  // update the system SSSP stage

  aos.ssspStage = AOS_SSSP_SHUTDOWN_1_2;

  return;

}

/**

 * @brief   Stops the system and all related threads (not the thread this function is called from).

 */

void aosSysStop(void)

{

#if (AMIROOS_CFG_SHELL_ENABLE == true)

  chThdWait(aos.shell->thread);

#endif

  return;

}

/**

 * @brief   Deinitialize all system variables.

 */

void aosSysDeinit(void)

{

  return;

}

/**

 * @brief   Finally shuts down the system and calls the bootloader callback function.

 * @note    This function should be called from the thtead with highest priority.

 *

 * @param[in] extDrv      Pointer to the interrupt driver.

 * @param[in] shutdown    Type of shutdown.

 */

void aosSysShutdownFinal(EXTDriver* extDrv, aos_shutdown_t shutdown)

{

  // check arguments

  aosDbgCheck(extDrv != NULL);

  aosDbgCheck(shutdown != AOS_SHUTDOWN_NONE);

  // stop external interrupt system

  extStop(extDrv);

  // update the system SSSP stage

  aos.ssspStage = AOS_SSSP_SHUTDOWN_1_3;

  // call bootloader callback depending on arguments

  switch (shutdown) {

    case AOS_SHUTDOWN_PASSIVE:

      BL_CALLBACK_TABLE_ADDRESS->cbHandleShutdownRequest();

      break;

    case AOS_SHUTDOWN_HIBERNATE:

      BL_CALLBACK_TABLE_ADDRESS->cbShutdownHibernate();

      break;

    case AOS_SHUTDOWN_DEEPSLEEP:

      BL_CALLBACK_TABLE_ADDRESS->cbShutdownDeepsleep();

      break;

    case AOS_SHUTDOWN_TRANSPORTATION:

      BL_CALLBACK_TABLE_ADDRESS->cbShutdownTransportation();

      break;

    case AOS_SHUTDOWN_RESTART:

      BL_CALLBACK_TABLE_ADDRESS->cbShutdownRestart();

      break;

    // must never occur

    case AOS_SHUTDOWN_NONE:

    default:

      break;

  }

  return;

}