DFU with sd_power_system_off

[Simon]

Is it possible for an app after having gone to sd_power_system_off to reset by button without triggering DFU?

The app seems to need CONFIG_GPIO_AS_PINRESET to be set so that button p0.21 can get the app to advertise again, but when DFU is loaded, the advertise becomes DfuTarg. I was looking at invoking DfuTarg only when button p0.21 is pressed as power is being applied.

For DFU I tried enter_method_button 1 with enter_method_button_pin 21 (the app after system_off, button pressed goes to DfuTarg) , and separately enter_method_pinreset 0 (the app after system_off, no response with button pressed, but advertises app after power toggle but then no DFU).

-thank-you.

[Einar Thorsrud]

Hi,

You can check the RESETREAS register in the dfu_enter_check() function in the bootloader to see if the reset was caused by pin reset or power on reset. Note that you have to use sd_power_reset_reason_get() and sd_power_reset_reason_clr() instead of accessing the registers directly if you are using the SoftDevice (as is the case for the BLE bootloader). The RESETREAS value will be all 0 (0x00000000) if a power on reset occurred.

[Simon]

An available example would better help to understand if there is one.

-thank-you

[Simon]

I have been using your code snippets for the custom which have been very helpful.
Using sdk15.0 standard SES examples I've been able to reproduce on the DK.
Attached are slightly modified ble_app_template and dfu examples (removed in both examples CONFIG_GPIO_AS_PINRESET, and added code snippet to dfu example, in dfu example file root directory is the FW zip file).
To reproduce:
- flash dfu example to DK, press and hold button 1 while cycle power, upload FW template by nRFconnect
- press button 1, template advertises, timeout, repeat press and still ok
- cycle power, template advertises, timeout, press button 1 and DfuTarg advertises (should be template).

-thank-you.

ble_app_template_case-1.zip        dfu_case-1.zip

[Einar Thorsrud]

Hi Simon,

Can you upload the code you have in the bootloader for deciding whether to enter DFU mode or not? I assume it is in nrf_bootloader.c, but it would be good to see the modifications you have done to the bootloader (including any libraries it uses).

[Simon]

Yes of course, the most important file. I had been using this sdk for the libraries nRF5_SDK_15_52810_bootloader_iar_keil_ses_gcc.zip. found at this case 32918.

Fullscreen nrf_bootloader.c Download

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 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */
#include "nrf_bootloader.h"

#include "compiler_abstraction.h"
#include "nrf.h"
#include "boards.h"
#include "sdk_config.h"
#include "nrf_power.h"
#include "nrf_delay.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_dfu.h"
#include "nrf_error.h"
#include "nrf_dfu_settings.h"
#include "nrf_dfu_utils.h"
#include "nrf_bootloader_wdt.h"
#include "nrf_bootloader_info.h"
#include "nrf_bootloader_app_start.h"
#include "nrf_bootloader_fw_activation.h"
#include "nrf_bootloader_dfu_timers.h"
#include "app_scheduler.h"
#include "app_timer.h"
#include "nrf_soc.h"

static nrf_dfu_observer_t m_user_observer; //<! Observer callback set by the user.

#define SCHED_QUEUE_SIZE      32          /**< Maximum number of events in the scheduler queue. */
#define SCHED_EVENT_DATA_SIZE MAX(NRF_DFU_SCHED_EVENT_DATA_SIZE, APP_TIMER_SCHED_EVENT_DATA_SIZE) /**< Maximum app_scheduler event size. */

#if !(defined(NRF_BL_DFU_ENTER_METHOD_BUTTON)    && \
      defined(NRF_BL_DFU_ENTER_METHOD_PINRESET)  && \
      defined(NRF_BL_DFU_ENTER_METHOD_GPREGRET)  && \
      defined(NRF_BL_DFU_ENTER_METHOD_BUTTONLESS))
    #error Configuration file is missing flags. Update sdk_config.h.
#endif

STATIC_ASSERT((NRF_BL_DFU_INACTIVITY_TIMEOUT_MS >= 100) || (NRF_BL_DFU_INACTIVITY_TIMEOUT_MS == 0),
             "NRF_BL_DFU_INACTIVITY_TIMEOUT_MS must be 100 ms or more, or 0 to indicate that it is disabled.");

#if defined(NRF_LOG_BACKEND_FLASH_START_PAGE)
STATIC_ASSERT(NRF_LOG_BACKEND_FLASH_START_PAGE != 0, 
    "If nrf_log flash backend is used it cannot use space after code because it would collide with settings page.");
#endif

/**@brief Weak implemenation of nrf_dfu_init
 *
 * @note   This function will be overridden if nrf_dfu.c is
 *         compiled and linked with the project
 */
 #if (__LINT__ != 1)
__WEAK uint32_t nrf_dfu_init(nrf_dfu_observer_t observer)
{
    NRF_LOG_DEBUG("in weak nrf_dfu_init");
    return NRF_SUCCESS;
}
#endif


/**@brief Weak implementation of nrf_dfu_init
 *
 * @note    This function must be overridden in application if
 *          user-specific initialization is needed.
 */
__WEAK uint32_t nrf_dfu_init_user(void)
{
    NRF_LOG_DEBUG("in weak nrf_dfu_init_user");
    return NRF_SUCCESS;
}


static void bootloader_reset(void)
{
    NRF_LOG_DEBUG("Resetting bootloader.");

    NRF_LOG_FINAL_FLUSH();

#if NRF_MODULE_ENABLED(NRF_LOG_BACKEND_RTT)
    // To allow the buffer to be flushed by the host.
    nrf_delay_ms(100);
#endif

    NVIC_SystemReset();
}


static void inactivity_timeout(void)
{
    NRF_LOG_INFO("Inactivity timeout.");
    bootloader_reset();
}


/**@brief Function for handling DFU events.
 */
static void dfu_observer(nrf_dfu_evt_type_t evt_type)
{
    switch (evt_type)
    {
        case NRF_DFU_EVT_DFU_STARTED:
        case NRF_DFU_EVT_OBJECT_RECEIVED:
            nrf_bootloader_dfu_inactivity_timer_restart(NRF_BL_DFU_INACTIVITY_TIMEOUT_MS, inactivity_timeout);
            break;
        case NRF_DFU_EVT_DFU_COMPLETED:
        case NRF_DFU_EVT_DFU_ABORTED:
            bootloader_reset();
            break;
        default:
            break;
    }

    if (m_user_observer)
    {
        m_user_observer(evt_type);
    }
}


/**@brief Function for initializing the event scheduler.
 */
static void scheduler_init(void)
{
    APP_SCHED_INIT(SCHED_EVENT_DATA_SIZE, SCHED_QUEUE_SIZE);
}


/**@brief Suspend the CPU until an interrupt occurs.
 */
static void wait_for_event(void)
{
#ifdef BLE_STACK_SUPPORT_REQD
    (void)sd_app_evt_wait();
#else
    // Wait for an event.
    __WFE();
    // Clear the internal event register.
    __SEV();
    __WFE();
#endif
}


/**@brief Continually sleep and process tasks whenever woken.
 */
static void loop_forever(void)
{
    while (true)
    {
        //feed the watchdog if enabled.
        nrf_bootloader_wdt_feed();

        app_sched_execute();

        if (!NRF_LOG_PROCESS())
        {
            wait_for_event();
        }
    }
}

/**@brief Function for initializing button used to enter DFU mode.
 */
static void dfu_enter_button_init(void)
{
    nrf_gpio_cfg_sense_input(NRF_BL_DFU_ENTER_METHOD_BUTTON_PIN,
                             BUTTON_PULL,
                             NRF_GPIO_PIN_SENSE_LOW);
}


static bool crc_on_valid_app_required(void)
{
    bool ret = true;
    if (NRF_BL_APP_CRC_CHECK_SKIPPED_ON_SYSTEMOFF_RESET &&
        (nrf_power_resetreas_get() & NRF_POWER_RESETREAS_OFF_MASK))
    {
        nrf_power_resetreas_clear(NRF_POWER_RESETREAS_OFF_MASK);
        ret = false;
    }
    else if (NRF_BL_APP_CRC_CHECK_SKIPPED_ON_GPREGRET2 &&
            (nrf_power_gpregret2_get() & BOOTLOADER_DFU_SKIP_CRC))
    {
        nrf_power_gpregret2_set(nrf_power_gpregret2_get() & ~BOOTLOADER_DFU_SKIP_CRC);
        ret = false;
    }
    else
    {
    }

    return ret;
}


/**@brief Function for clearing all DFU enter flags that
 *        preserve state during reset.
 *
 * @details This is used to make sure that each of these flags
 *          is checked only once after reset.
 */
static void dfu_enter_flags_clear(void)
{
    if (NRF_BL_DFU_ENTER_METHOD_PINRESET &&
       (NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk))
    {
        // Clear RESETPIN flag.
        NRF_POWER->RESETREAS |= POWER_RESETREAS_RESETPIN_Msk;
    }

    if (NRF_BL_DFU_ENTER_METHOD_GPREGRET &&
       (nrf_power_gpregret_get() & BOOTLOADER_DFU_START))
    {
        // Clear DFU mark in GPREGRET register.
        nrf_power_gpregret_set(nrf_power_gpregret_get() & ~BOOTLOADER_DFU_START);
    }

    if (NRF_BL_DFU_ENTER_METHOD_BUTTONLESS &&
       (s_dfu_settings.enter_buttonless_dfu == 1))
    {
        // Clear DFU flag in flash settings.
        s_dfu_settings.enter_buttonless_dfu = 0;
        APP_ERROR_CHECK(nrf_dfu_settings_write(NULL));
    }
}


/**@brief Function for checking whether to enter DFU mode or not.
 */
static bool dfu_enter_check(void)
{

	/* Configure wakeup pin */
	nrf_gpio_cfg_sense_input(BSP_BUTTON_0, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW);

	if (NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk)
	{
			NRF_POWER->RESETREAS = ~POWER_RESETREAS_RESETPIN_Msk;
	}


	if (!nrf_dfu_app_is_valid(crc_on_valid_app_required()))
    {
//        NRF_LOG_DEBUG("DFU mode because app is not valid.");
//        return true;
    }

//		if (NRF_BL_DFU_ENTER_METHOD_BUTTON &&
//       (nrf_gpio_pin_read(NRF_BL_DFU_ENTER_METHOD_BUTTON_PIN) == 0))
//    {
//        NRF_LOG_DEBUG("DFU mode requested via button.");
//        return true;
//    }
		
//    if (NRF_BL_DFU_ENTER_METHOD_BUTTON &&
//       (nrf_gpio_pin_read(NRF_BL_DFU_ENTER_METHOD_BUTTON_PIN) == 0))
////		if ((nrf_gpio_pin_read(21) == 0))
//       
//    {
////        NRF_LOG_DEBUG("DFU mode requested via button.");
////        return true;

//				uint32_t reset_reason;
//				sd_power_reset_reason_get(&reset_reason);
//				sd_power_reset_reason_clr(~0);		
//				if (reset_reason > 0)			
//				{
//						NRF_LOG_DEBUG("Ignoring DFU button as device is not powered cycled.");
//				}
//				else
//				{
//						NRF_LOG_DEBUG("DFU mode requested via button after power on reset.");
//						return true;			
//				}	
//    }

		if (NRF_BL_DFU_ENTER_METHOD_BUTTON &&
		(nrf_gpio_pin_read(NRF_BL_DFU_ENTER_METHOD_BUTTON_PIN) == 0))
    {		
//				/* Configure wakeup pin */
//				nrf_gpio_cfg_sense_input(BSP_BUTTON_0, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW);

//				if (NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk)
//				{
//						NRF_POWER->RESETREAS = ~POWER_RESETREAS_RESETPIN_Msk;
//				}

//				if(NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk)
//				{
//				}
////				else if (NRF_POWER->RESETREAS == 0)
////				{
////						// Check if wake-up button is also pressed (even if we woke up due to power on reset)
////						if(nrf_gpio_pin_read(BSP_BUTTON_0) == 0)
////						{
////								// Wake up from power on reset *AND* wakeup button is pushed. This is where we enter DFU mode!
////								return true;
////						}
////				}
//				else if (NRF_POWER->RESETREAS == 0)
//				{
//						// Check if wake-up button is also pressed (even if we woke up due to power on reset)
//						if(nrf_gpio_pin_read(BSP_BUTTON_0) == 0)
//						{
//								// Wake up from power on reset *AND* wakeup button is pushed. This is where we enter DFU mode!
//								return true;
//						}
//				}		


				
//				if (NRF_POWER->RESETREAS == 0 && nrf_gpio_pin_read(BSP_BUTTON_0) == 0)
//				{
//					if (NRF_POWER->RESETREAS & !POWER_RESETREAS_OFF_Msk)
//					{
//						return false;
//					}					
//					else
//					{
//						return true;
//					}
//				}

    if(NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk)
    {
        // Light LED 1 to indicate pin reset
//        bsp_board_led_on(0);
			    return false;
    }
    else if (NRF_POWER->RESETREAS == 0)
    {
        // Light LED 2 to indicate power on or brown out reset
//        bsp_board_led_on(1);
			

        // Check if wake-up button is also pressed (even if we woke up due to power on reset)
        if(nrf_gpio_pin_read(BSP_BUTTON_0) == 0)
        {
            // Wake up from power on reset *AND* wakeup button is pushed. This is were we enter DFU mdoe!
            // Light LED 3 as well to indicate GPIO pin is pressed.
//            bsp_board_led_on(2);
											return true;					
        }
				else
				{
					return false;
				}				
				
    }
    else if (NRF_POWER->RESETREAS & POWER_RESETREAS_OFF_Msk)
    {
        // Light LED 3 to indicate wakeup from GPIO (without power cycle)
//        bsp_board_led_on(2);
			    return false;
    }
    else
    {
        // Light LED 4 to indicate other wakeup reason
//        bsp_board_led_on(3);
    return false;
    }
		
		}



//    if (NRF_BL_DFU_ENTER_METHOD_PINRESET &&
//       (NRF_POWER->RESETREAS & POWER_RESETREAS_RESETPIN_Msk))
//    {
//        NRF_LOG_DEBUG("DFU mode requested via pin-reset.");
//        return true;
//    }

//    if (NRF_BL_DFU_ENTER_METHOD_GPREGRET &&
//       (nrf_power_gpregret_get() & BOOTLOADER_DFU_START))
//    {
//        NRF_LOG_DEBUG("DFU mode requested via GPREGRET.");
//        return true;
//    }

//    if (NRF_BL_DFU_ENTER_METHOD_BUTTONLESS &&
//       (s_dfu_settings.enter_buttonless_dfu == 1))
//    {
//        NRF_LOG_DEBUG("DFU mode requested via bootloader settings.");
//        return true;
//    }

    return false;
}


ret_code_t nrf_bootloader_init(nrf_dfu_observer_t observer)
{
    NRF_LOG_DEBUG("In nrf_bootloader_init");

    uint32_t                              ret_val;
    nrf_bootloader_fw_activation_result_t activation_result;
    uint32_t                              initial_timeout;
    bool                                  dfu_enter = false;

    m_user_observer = observer;

    if (NRF_BL_DFU_ENTER_METHOD_BUTTON)
    {
        dfu_enter_button_init();
    }

    ret_val = nrf_dfu_settings_init(false);
    if (ret_val != NRF_SUCCESS)
    {
        return NRF_ERROR_INTERNAL;
    }

    // Check if an update needs to be activated and activate it.
    activation_result = nrf_bootloader_fw_activate();

    switch (activation_result)
    {
        case ACTIVATION_NONE:
            initial_timeout = NRF_BL_DFU_INACTIVITY_TIMEOUT_MS;
            dfu_enter       = dfu_enter_check();
            break;

        case ACTIVATION_SUCCESS_EXPECT_ADDITIONAL_UPDATE:
            initial_timeout = NRF_BL_DFU_CONTINUATION_TIMEOUT_MS;
            dfu_enter       = true;
            break;

        case ACTIVATION_SUCCESS:
            bootloader_reset();
            NRF_LOG_ERROR("Should never come here: After bootloader_reset()");
            return NRF_ERROR_INTERNAL; // Should not reach this.

        case ACTIVATION_ERROR:
        default:
            return NRF_ERROR_INTERNAL;
    }

    if (dfu_enter)
    {
        nrf_bootloader_wdt_init();

        scheduler_init();

        // Clear all DFU stop flags.
        dfu_enter_flags_clear();

        // Call user-defined init function if implemented
        ret_val = nrf_dfu_init_user();
        if (ret_val != NRF_SUCCESS)
        {
            return NRF_ERROR_INTERNAL;
        }

        nrf_bootloader_dfu_inactivity_timer_restart(initial_timeout, inactivity_timeout);

        ret_val = nrf_dfu_init(dfu_observer);
        if (ret_val != NRF_SUCCESS)
        {
            return NRF_ERROR_INTERNAL;
        }

        NRF_LOG_DEBUG("Enter main loop");
        loop_forever(); // This function will never return.
        NRF_LOG_ERROR("Should never come here: After looping forever.");
    }
    else
    {
        // Erase additional data like peer data or advertisement name
        ret_val = nrf_dfu_settings_additional_erase();
        if (ret_val != NRF_SUCCESS)
        {
            return NRF_ERROR_INTERNAL;
        }

        nrf_bootloader_app_start();
        NRF_LOG_ERROR("Should never come here: After nrf_bootloader_app_start()");
    }

    // Should not be reached.
    return NRF_ERROR_INTERNAL;
}

[Einar Thorsrud]

With this code, NRF_POWER->RESETREAS must be 0 in order to enter DFU mode (in addition to the button press), and the only situations where it should be all zero are:

• Power on reset
• Brownout reset
• NRF_POWER->RESETREAS has been cleared before it is read (after reset)

The crc_on_valid_app_required() is called before you do the other check, and this will clear the RESETREAS in some cases. Can you move this check to the end of the dfu_enter_check function? Then you should also remove all the "return false" statements, and only return false in the end of the function if no of the "positive" cases are hit.

[Simon]

It was in the sequence, great.

-thank-you.