Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

musk — Mon, 22 Apr 2019 12:00:25 GMT

Does RTC timer need to be turned off?

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

musk — Mon, 22 Apr 2019 11:57:42 GMT

Thank you very mach

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

Bruno Randolf — Mon, 22 Apr 2019 11:56:05 GMT

The workaround is essentially described above. You trigger the watchdog from your main.c of the bootloader... in my case the code looks like this:

static void feed_wdt(void)
{
	if (nrf_wdt_reload_request_is_enabled(NRF_WDT_RR0)) {
		nrf_wdt_reload_request_set(NRF_WDT_RR0);
	}
}

void wd_timer_handler(nrf_timer_event_t event_type, void* p_context)
{
	switch (event_type) {
		case NRF_TIMER_EVENT_COMPARE0:
			feed_wdt();
			break;
		default:
			break;
	}
}

static void timer_start()
{
	if (!nrf_wdt_started())
		return;

	NRF_LOG_INFO("Workaround to feed WDT");
	nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
	uint32_t err_code = nrf_drv_timer_init(&wd_timer, &timer_cfg,
					       wd_timer_handler);
	APP_ERROR_CHECK(err_code);
	nrf_drv_timer_extended_compare(&wd_timer, NRF_TIMER_CC_CHANNEL0,
				nrf_drv_timer_ms_to_ticks(&wd_timer, 2000),
				NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);

	nrf_drv_timer_enable(&wd_timer);
}

/* This is called from nrf_bootloader_init() just before DFU starts */
ret_code_t nrf_dfu_init_user()
{
	timer_start();
	return NRF_SUCCESS;
}

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

musk — Mon, 22 Apr 2019 11:51:07 GMT

What should I do about it

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

Bruno Randolf — Mon, 22 Apr 2019 11:48:36 GMT

The same issue is present with SDK 15.3.0 and without -flto

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

musk — Fri, 19 Apr 2019 09:36:05 GMT

I have the same problem:but I can't solve it,

Can you send file to my email?
email:739112417@qq.com.
Thank you very much

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

jeremysf — Thu, 21 Feb 2019 16:58:02 GMT

Glad to hear you got it working!

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

Bruno Randolf — Wed, 20 Feb 2019 20:05:45 GMT

Ok sorry my mistake... the workaround works, after setting NRFX_TIMER_DEFAULT_CONFIG_FREQUENCY right...

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

Bruno Randolf — Wed, 20 Feb 2019 19:18:57 GMT

I have the same problem: Serial bootloader, and when the watchdog is enabled in my app the timers fail in the same way (it seems like all timers in the bootloader are never triggered) and the WDT is not fed. Unfortunately your workaround doesn't work for me either...

Did you use the SoftDevice or MBR?

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

jeremysf — Thu, 21 Jun 2018 17:19:51 GMT

Hmm, yeah, not sure what's up. I will try out your changed nrf_bootloader.c on my hardware, with my config, with my version of gcc, etc.

For now, I'm happy with my solution to use nrf_drv_timer in main.c, as it co-exists side by side with the existing code in the bootloader library (which fails to work for me), so if it ends up being a config issue, or compiler issue, or bug in my custom hardware, it would be easy to remove.

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

Hung Bui — Thu, 21 Jun 2018 11:34:32 GMT

Strange that app_timerv2 didn't work for you.

Attached is the nrf_bootloader.c file I modified to start a WDT that timeout in 7 seconds and then change the nrf_bootloader_dfu_inactivity_timer_restart() to blink an LED after 10 seconds, I didn't see the WDT triggered any reset. ( I commented out the feeding in the main loop).

devzone.nordicsemi.com/.../nrf_5F00_bootloader.c

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

jeremysf — Thu, 21 Jun 2018 07:26:18 GMT

So I have things working, but basically, as above, if I have WDT enabled in my app, the app timers in the bootloader library component do not work at all for me (neither the timer to feed the WDT nor the inactivity timeout).

So instead, I am using the nrfx_timer library myself and handling the feeding of the WDT and resetting for inactivity in the main.c of the secure bootloader.

So in my modified main.c of the secure bootloader example, I have code like the following:

...
#include "nrf_drv_timer.h"
#include "nrf_wdt.h"

const nrf_drv_timer_t ACTIVITY_TIMER = NRF_DRV_TIMER_INSTANCE(0);

#define COUNTDOWN_INIT 30

static int countdown = COUNTDOWN_INIT;

void feed_wdt() 
{
    if (nrf_wdt_started())
    {
        for (nrf_wdt_rr_register_t i = NRF_WDT_RR0; i < NRF_WDT_RR7; i++)
        {
            if (nrf_wdt_reload_request_is_enabled(i))
            {
                nrf_wdt_reload_request_set(i);
            }
        }
    }        
}

static void dfu_observer(nrf_dfu_evt_type_t evt_type)
{
    switch (evt_type)
    {
        case NRF_DFU_EVT_DFU_COMPLETED:
        case NRF_DFU_EVT_DFU_ABORTED:
            nrf_drv_timer_disable(&ACTIVITY_TIMER);
            break;
        case NRF_DFU_EVT_DFU_STARTED:
        case NRF_DFU_EVT_OBJECT_RECEIVED:
            countdown = COUNTDOWN_INIT;
            feed_wdt();
            break;
        default:
            break;
    }
}

void activity_timer_event_handler(nrf_timer_event_t event_type, void* p_context)
{
    switch (event_type)
    {
        case NRF_TIMER_EVENT_COMPARE0:
            countdown--;
            if( countdown < 0) {
                nrf_drv_timer_disable(&ACTIVITY_TIMER);
                NVIC_SystemReset();    
            } else {
                feed_wdt();
            }
            break;

        default:
            //Do nothing.
            break;
    }
}


int main(void) {
    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
    uint32_t err_code = nrf_drv_timer_init(&ACTIVITY_TIMER, &timer_cfg, activity_timer_event_handler);
    APP_ERROR_CHECK(err_code);
    nrf_drv_timer_extended_compare(
         &ACTIVITY_TIMER, NRF_TIMER_CC_CHANNEL0, nrf_drv_timer_ms_to_ticks(&ACTIVITY_TIMER, 500), NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
    nrf_drv_timer_enable(&ACTIVITY_TIMER);

    // Protect MBR and bootloader code from being overwritten.
    uint32_t ret_val = nrf_bootloader_flash_protect(0, MBR_SIZE, false);
    APP_ERROR_CHECK(ret_val);
    ...
}

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

jeremysf — Thu, 21 Jun 2018 02:12:43 GMT

A little bit more information: I built the debug version of the bootloader, and configured it to log to SEGGER_RTT over SWD/JLINK.

Here we can see that the nrf_bootloader_wdt detected that the WDT was enabled, and notice it says that it is starting a timer to feed the WDT and it sits idle at the log entry "<debug> app: Enter main loop".

However at 10s after entering the bootloader, it is rebooted, and we can see the log entry "<info> app: Inside main". So the WDT is actually NOT being fed.

I suspect that what is happening is that the event loop / app_scheduler is not working for some reason when the WDT is enabled, and neither the app timer for feeding the WDT nor the app timer for NRF_BL_INACTIVITY_TIMEOUT_MS are working. The puzzling thing is this is only when the WDT is enabled. Otherwise, things work.

<info> app: Inside main
<debug> app: In nrf_bootloader_init
<debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> app: Enter nrf_bootloader_fw_activate
<info> app: No firmware to activate.
<debug> app: Enter nrf_dfu_app_is_valid
<debug> app: Return true. App was valid
<debug> app: DFU mode requested via GPREGRET.
<info> nrf_bootloader_wdt: WDT enabled CRV:10240 ms
<info> nrf_bootloader_wdt: Starting a timer (7680 ms) for feeding watchdog.
<info> app_timer: RTC: initialized.
<debug> app: in weak nrf_dfu_init_user
<info> app: Entering DFU mode.
<debug> app: Initializing transports (found: 1)
<debug> nrf_dfu_serial_uart: serial_dfu_transport_init()
<debug> nrf_dfu_serial_uart: serial_dfu_transport_init() completed
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> app: Enter main loop
<info> app: Inside main
<debug> app: In nrf_bootloader_init
<debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> app: Enter nrf_bootloader_fw_activate
<info> app: No firmware to activate.
<debug> app: Enter nrf_dfu_app_is_valid
<debug> app: Return true. App was valid
<warning> nrf_dfu_settings: No additional data erased
<debug> app: Running nrf_bootloader_app_start with address: 0x00001000
<debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0
<debug> app: running irq table set
<debug> app: After running irq table set

Here is what the log looks like if I disable the WDT, and the NRF_BL_INACTIVITY_TIMEOUT_MS works:

<info> app: Inside main
<debug> app: In nrf_bootloader_init
<debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> app: Enter nrf_bootloader_fw_activate
<info> app: No firmware to activate.
<debug> app: Enter nrf_dfu_app_is_valid
<debug> app: Return true. App was valid
<debug> app: DFU mode requested via GPREGRET.
<info> nrf_bootloader_wdt: WDT is not enabled
<debug> app: scheduler init
<debug> app: in weak nrf_dfu_init_user
<info> app_timer: RTC: initialized.
<info> app: Entering DFU mode.
<debug> app: Initializing transports (found: 1)
<debug> nrf_dfu_serial_uart: serial_dfu_transport_init()
<debug> nrf_dfu_serial_uart: serial_dfu_transport_init() completed
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> app: Enter main loop
<debug> app: wait_for_event
<debug> app: wait_for_event
<info> app: Inactivity timeout.
<debug> app: Resetting bootloader.
<info> app: Inside main
<debug> app: In nrf_bootloader_init
<debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> app: Enter nrf_bootloader_fw_activate
<info> app: No firmware to activate.
<debug> app: Enter nrf_dfu_app_is_valid
<debug> app: Return true. App was valid
<warning> nrf_dfu_settings: No additional data erased
<debug> app: Running nrf_bootloader_app_start with address: 0x00001000
<debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0
<debug> app: running irq table set
<debug> app: After running irq table set

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

jeremysf — Thu, 21 Jun 2018 01:49:26 GMT

Ok, I added the following lines to the top of the secure bootloader main.c:

void wdt_event_handler(void) {
    NVIC_SystemReset();    
}

int main(void) {
    uint32_t err_code;
    nrf_drv_wdt_config_t config = {                                           \
        .behaviour          = (nrf_wdt_behaviour_t)1, \
        .reload_value       = 10000,                   \
        .interrupt_priority = 7,                   \
    };
    err_code = nrf_drv_wdt_init(&config, wdt_event_handler);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_wdt_channel_alloc(&m_channel_id);
    APP_ERROR_CHECK(err_code);
    nrf_drv_wdt_enable(); 

    // Protect MBR and bootloader code from being overwritten.
    uint32_t ret_val = nrf_bootloader_flash_protect(0, MBR_SIZE, false);
    APP_ERROR_CHECK(ret_val);
    ret_val = nrf_bootloader_flash_protect(BOOTLOADER_START_ADDR, BOOTLOADER_SIZE, false);
    APP_ERROR_CHECK(ret_val);
    ...

I also enable the WDT in the config, added nrfx_wdt.c to the Makefile and had to comment out WDT_IRQHandler from nrf_bootloader_wdt.c which conflicts with the one in nrfx_wdt.c.

For this test, I removed all WDT code from my application.

When I run enter the bootloader, the WDT will fire after 10s and bring me back from the bootloader to my application (via a soft reset). In other words, the WDT is not being "fed" or reset. No matter what I set the NRF_BL_INACTIVITY_TIMEOUT_MS to, it does not fire (i.e. 5s, 2s, etc) when the WDT is enabled.

If I remove this WDT code from the top of the secure boot loader example's main.c, then the NRF_BL_INACTIVITY_TIMEOUT_MS works. I can set it to 5s, 2s (i.e. 5000ms or 2000ms) and it correctly brings me back from the bootloader to my application after the specified idle period.

To be clear, I would expect with this added WDT code, and the NRF_BL_INACTIVITY_TIMEOUT_MS set to 5s, that after 5s of idle, it would reset back to my application. I would further expect if I set the WDT to 2s (i.e. 2000ms) with the NRF_BL_INACTIVITY_TIMEOUT_MS set to 10s, that nothing would happen at 2s (because the WDT should be being fed by the code in nrf_bootloader_wdt.c).

Thoughts?

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

jeremysf — Wed, 20 Jun 2018 17:19:06 GMT

Yes, I can confirm that I mean that I changed NRF_BL_INACTIVITY_TIMEOUT_MS to be 10s (ie 10000). When I do enable the WDT in my app, I am able to see that inactivity timeout taking effect (and changes to it taking effect).

Enabling the WDT in my app, I can feed it in my app, but I can’t get the boot loader to feed it, and it seems to cause the inactivity timer to no longer work.

I will try starting the WDT in the bootloader as a test as you suggest.

RE: Entering DFU via GPREGET, secure bootloader serial example not feeding WDT in SDKv15

Hung Bui — Wed, 20 Jun 2018 13:01:38 GMT

Hi Jeremy,

Could you clarify the inactivity timeout is 10 seconds ? By default our inactivity timeout is 120 seconds: NRF_BL_DFU_INACTIVITY_TIMEOUT_MS = 120000

We do have a 10 second timeout but it's the timeout after you update the softdevice and waiting for the application to be updated for example. (NRF_BL_DFU_CONTINUATION_TIMEOUT_MS)

Could you try to test by simply starting the WDT in the bootloader and see if there is any difference ?