How to stay in bootloader in case of faulty app?

RE: How to stay in bootloader in case of faulty app?

Hung Bui — Fri, 14 Aug 2020 11:18:39 GMT

Hi Jerome,
This is a very old case. Please create a new case for your issue.
From what I can see you are doing a 10 seconds delay. It's not a timer. Please look for how we do the inactivity app timer in our bootloader. You can configure a similar app timer that does the wait. It's the same app timer that you can find in our example, for example battery update timer in ble_app_hrs.

RE: How to stay in bootloader in case of faulty app?

JayLynkz — Thu, 13 Aug 2020 20:14:10 GMT

Hi !

I've tried to insert a timer in the bootloader. The result is that the MCU does wait for the indicated delay before launching the app, but it does not advertise as a DFU targ.

I've tried to insert the timer at different places in the bootloader code (which is the 'secure_bootloader_ble_s132_pca10040') and it does not work (I've inserted the 'main' function of this code below).

My questions are :

1. Where should I insert the timer so it still advertise ?

2. Where in the bootloader is the avdertisement managed ?

I am using SES on windows for a nrf52832

Thank you !

int main(void)
{
    uint32_t ret_val;

    // Must happen before flash protection is applied, since it edits a protected page.
    nrf_bootloader_mbr_addrs_populate();
    
    // Protect MBR and bootloader code from being overwritten.
    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);

    (void) NRF_LOG_INIT(nrf_bootloader_dfu_timer_counter_get);
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    NRF_LOG_INFO("Inside main");

    ret_val = nrf_bootloader_init(dfu_observer);
    APP_ERROR_CHECK(ret_val);

    nrf_delay_ms(10000);

    NRF_LOG_FLUSH();

    NRF_LOG_ERROR("After main, should never be reached.");
    NRF_LOG_FLUSH();

    APP_ERROR_CHECK_BOOL(false);
}

RE: How to stay in bootloader in case of faulty app?

Hung Bui — Mon, 15 Jan 2018 14:49:33 GMT

I think it's a good idea.

In your bootloader you can simply check if the GPREGRET flag is set then it should be something wrong with the app and stay in DFU mode. If it's not set then you set it and start the WDT expecting the flag to be cleared when the app start.

Another option is to set a timer when bootloader start, for example it waits for 5 seconds if there is no DFU connection, then it will start the application. So you can recover if there is anything wrong. The draw back is a latency of a few seconds after the device powered until it operates.