WatchDog Control

Support two watchdog controls of the board. If the watchdog begins and reaches the pre-set time, it will access the CPU’s RESET signal to reset the system.

watchdog_timing_chart

  • Run-Time Watchdog: used in the OS to monitor the process or the application. BIOS also provides the capability to enable, disable and setup timeout value on BIOS Menu. If enable run-time watchdog on BIOS menu, please make a trigger to extend the timeout or system reboot.

    Note: timeout value will continuously keep until run-time watchdog is disabled on BIOS Menu or using SEMA functions to stop it.

  • Power-up Watchdog: used to supervise the boot process between system power-on to the operating system loading. When BIOS POST can be successfully booted, BIOS will clear power-up watchdog and go to OS bootloader. BIOS also provides the capability to enable, disable and setup timeout value on BIOS Menu.

    Note: Reboot system is a must after using SEMA function to enable power-up watchdog.


sysfs Interfaces

For Run-time Watchdog:

  • To start/update the run-time watchdog with timeout out value, use the following format:

    wdogtest –timeout=<time in seconds>

    The example below sets the run-time watchdog timeout value as 20 seconds.

    wdogtest –timeout=20

  • To stop the run-time watchdog ( Timeout value will be set to ‘0’. Please set timeout again)

    echo "V" > /dev/watchdog0

  • To trigger / ping the run-time watchdog

    wdogtest –ping

  • To get the information about the run-time watchdog state

    cat /sys/class/watchdog/watchdog0/state
  • To get the current run-time watchdog timeout value ( timeout value is not the elapsed time. it is your initial timeout) 
    cat /sys/class/watchdog/watchdog0/timeout
  • To get minimum/maximum run-time watchdog timeout value
    /sys/bus/platform/devices/adl-bmc-wdt/Capabilities/wdt_min_timeout
    /sys/bus/platform/devices/adl-bmc-wdt/Capabilities/wdt_max_timeout
For Power-up Watchdog

  • To start / update the power-up watchdog timer value:

    echo <time in seconds> /sys/bus/platform/devices/adl-bmc-wdt/Capabilities/PwrUpWDog

    The example below sets the power-up watchdog timer timeout value as 1000 seconds:

    echo 1000 > /sys/bus/platform/devices/adl-bmc-wdt/Capabilities/PwrUpWDog

  • To get the power-up watchdog timer value

    cat /sys/bus/platform/devices/adl-bmc-wdt/Capabilities/PwrUpWDog

  • To stop the power-up watchdog timer

    echo 0 > /sys/bus/platform/devices/adl-bmc-wdt/Capabilities/PwrUpWDog


SEMA EAPI (Both Windows & Linux supported)

Get the capabilities of run-time watchdog

uint32_t EApiWDogGetCap(
    uint32_t *pMaxDelay,
    uint32_t *pMaxEventTimeout,
    uint32_t* Resetvalue
)

  • Parameters:

    • uint32_t *pMaxDelay:

      Pointer to a buffer that receives maximum supported initial delay time of the watchdog timer in milliseconds.

    • uint32_t *pMaxEventTimeout:

      Pointer to a buffer that receives maximum supported event timeout of the watchdog timer in milliseconds.

    • uint32_t* Resetvalue:

      Pointer to a buffer that receives maximum supported event timeout of the watchdog timer in milliseconds.


Start to run-time watchdog timer. To reset timer value, timer must be stopped by using EApiWDogStop() and then EApiWDogStart() be called again with new values. 

uint32_t EApiWDogStart(
    uint32_t delay,
    uint32_t EventTimeout,
    uint32_t ResetTime
)

  • Parameters:

    • uint32_t delay:

      Initial delay for the watchdog timer in milliseconds. (currently not supported by SEMA EAPI, set it as 0)

    • uint32_t EventTimeout:

      Initial delay for the watchdog timer in milliseconds. (currently not supported by SEMA EAPI, set it as 0)

    • uint32_t ResetTime:

      Watchdog timeout interval in milliseconds to trigger a reset.


Reset the run-time watchdog timer

uint32_t EApiWDogTrigger()


Stop the operation of the run-time watchdog timer

uint32_t EApiWDogStop()


Enable the operation of the power-up watchdog timer

uint32_t EApiPwrUpWDogStart( uint32_t ResetTime)

  • Parameters:

    • uint32_t ResetTime:

      Watchdog timeout interval in milliseconds to trigger a reset.


Disable the operation of the power-up watchdog timer (disable)

uint32_t EApiPwrUpWDogStop()