Secure bootloader - SDK12.2.0

RE: Secure bootloader - SDK12.2.0

yichen — Wed, 12 Jul 2017 06:04:13 GMT

can you tell me how you do in dfu mode with wdt...thank you very much

RE: Secure bootloader - SDK12.2.0

yichen — Wed, 12 Jul 2017 06:03:32 GMT

i open the wdt, and in the efu, i start a timer with 1 second, void wdt_timeout_handler(void * p_context) { nrf_gpio_pin_toggle(18); NRF_WDT->RR[0]=WDT_RR_RR_Reload; } #define WDT_INTERVAL APP_TIMER_TICKS(1000,APP_TIMER_PRESCALER)

APP_TIMER_DEF(wdt_timer_id);

when i not open the wdt,i let NRF_POWER->GPREGRET == BOOTLOADER_DFU_START,and it in dfu mode,the led is togle,mains that the timer is work. and then,i open the wdt,#define WDT_CONFIG_RELOAD_VALUE 7000, then i can't come in dfu mode,when i send dfu cmd,after 7 second ,the device is restart in application mode

RE: Secure bootloader - SDK12.2.0

kagislason — Thu, 05 Jan 2017 17:54:52 GMT

Sorry for the late answer, did not get a notification of this comment.

I added this to my main application, after receiving a firmware update request from the central I set the GPREGRET register as "some hex code" and then restart the chip. Afterwards it wakes up in bootloader and checks if NRF_POWER->GPREGRET == "some hex code", if so I start DFU else boot up into main.

As for the bond information I did not implement anything there for now, I will need to take another spin at this soon.

Hope this helps.

RE: Secure bootloader - SDK12.2.0

WestCoastDaz — Fri, 09 Dec 2016 23:41:56 GMT

kagislason,

I am I correct in assuming that you either rewrote or modified ble_dfu.c to achieve the desired functionality? You said "On the application side I set the register and then call my power reset function (housekeeping then restart):" Where did you add this functionality, did you care about the bond data?

RE: Secure bootloader - SDK12.2.0

WestCoastDaz — Fri, 09 Dec 2016 22:23:20 GMT

kagislason,

Thanks for the help, I really appreciate it!

As for the WDT issue I'm glad I was able to help. Beware Nordic's implementation of the WDT is very different that anything I have used in previous micro's. Once it's turned on it can't be turned off via software! It can only be stopped by a hardware reset or BOR/PUR.

RE: Secure bootloader - SDK12.2.0

kagislason — Fri, 09 Dec 2016 10:31:58 GMT

As for the GPREGRET solution I set the register in my main application when receiving a firmware update request from our iOS app. This feature is protected with user roles and then using a unique static pin code/MITM protection.

On the application side I set the register and then call my power reset function (housekeeping then restart):

sd_power_gpregret_set(0, (uint32_t)BOOTLOADER_DFU_START);

In the bootloader I override the __WEAK nrf_dfu_enter_check() function. I removed the button/flash logic and added a check for GPREGRET:

   if (NRF_POWER->GPREGRET == BOOTLOADER_DFU_START)
   {
      NRF_POWER->GPREGRET = 0;
      return true;
   }
   return false;

RE: Secure bootloader - SDK12.2.0

kagislason — Fri, 09 Dec 2016 10:30:46 GMT

This was indeed a watchdog issue, thanks!

I was not aware that the watchdog would keep running after a soft reset. I had already done a WDT reload in the wait_for_event() function but I fixed the issue by also kicking the dog while processing the new firmware. I don't like modifying SDK files (for future updates and clarity) so I will try to find a more elegant solution.

RE: Secure bootloader - SDK12.2.0

WestCoastDaz — Thu, 08 Dec 2016 19:08:11 GMT

kagislason,

Do you have the watchdog turned on? If so you need to keep kicking it in the boot loader.

Also, are you willing to share the changes you made to return to using GPREGRET? I'm just about to do this on our design.

Cheers