esp-idf/components/esp_system/Kconfig

menu "ESP System Settings"

    choice ESP_SYSTEM_PANIC
        prompt "Panic handler behaviour"
        default ESP_SYSTEM_PANIC_PRINT_REBOOT
        help
            If FreeRTOS detects unexpected behaviour or an unhandled exception, the panic handler is
            invoked. Configure the panic handler's action here.

        config ESP_SYSTEM_PANIC_PRINT_HALT
            bool "Print registers and halt"
            help
                Outputs the relevant registers over the serial port and halt the
                processor. Needs a manual reset to restart.

        config ESP_SYSTEM_PANIC_PRINT_REBOOT
            bool "Print registers and reboot"
            help
                Outputs the relevant registers over the serial port and immediately
                reset the processor.

        config ESP_SYSTEM_PANIC_SILENT_REBOOT
            bool "Silent reboot"
            help
                Just resets the processor without outputting anything

        config ESP_SYSTEM_PANIC_GDBSTUB
            bool "Invoke GDBStub"
            select ESP_GDBSTUB_ENABLED
            help
                Invoke gdbstub on the serial port, allowing for gdb to attach to it to do a postmortem
                of the crash.
    endchoice

    config ESP_SYSTEM_SINGLE_CORE_MODE
        bool
        default n
        help
            Only initialize and use the main core.

    config ESP_SYSTEM_RTC_EXT_XTAL
        # This is a High Layer Kconfig option, invisible, can be selected by other Kconfig option
        # e.g. It will be selected on when ESP32_RTC_CLK_SRC_EXT_CRYS is on
        bool
        default n

    config ESP_SYSTEM_RTC_EXT_XTAL_BOOTSTRAP_CYCLES
        int "Bootstrap cycles for external 32kHz crystal"
        depends on ESP_SYSTEM_RTC_EXT_XTAL
        default 5 if IDF_TARGET_ESP32
        default 0
        range 0 32768
        help
            To reduce the startup time of an external RTC crystal,
            we bootstrap it with a 32kHz square wave for a fixed number of cycles.
            Setting 0 will disable bootstrapping (if disabled, the crystal may take
            longer to start up or fail to oscillate under some conditions).

            If this value is too high, a faulty crystal may initially start and then fail.
            If this value is too low, an otherwise good crystal may not start.

            To accurately determine if the crystal has started,
            set a larger "Number of cycles for RTC_SLOW_CLK calibration" (about 3000).

endmenu  # ESP System Settings