System hangs switching from Application to Bootloader

RE: System hangs switching from Application to Bootloader

Edvin — Wed, 13 May 2020 09:21:49 GMT

Glad to hear that you found the issue!

Just one comment regarding the delay after you set the gpregret register. Perhaps it is even safer to use a while() to check the register:

uint8_t reg_val = nrf_power_gpregret_get();
reg_val = reg_val | 0xB1; /* Set bit 1 to trigger DFU */
nrf_power_gpregret_set(reg_val);

reg_val = 0x00; /* reset test value */
while ((reg_val & 0xB1) != 0xB1)
{
    reg_val = nrf_power_gpregret_get();
}
NVIC_Systemreset();

The point of the delay is to not reset until the register is properly written, so reading the register until it is correct would give the accurate delay.

RE: System hangs switching from Application to Bootloader

Locky — Tue, 12 May 2020 23:36:57 GMT

Found the issue. The Flash memory section which contains the MDR and Settings seems to be corrupted. Not entire unexpected as the PCA10040 I'm using has be developed on for years.. I verified that some sections of the Flash for the MBR and Bootsettings were not saving properly. Caused issued with system resets but not power resets oddly enough.

RE: System hangs switching from Application to Bootloader

Locky — Tue, 12 May 2020 16:20:03 GMT

Hi Edvin,

As I previously mentioned, I did this and it works the same as my bootloader. Successfully updates the Application. But when I triigger a new update from the Application via

/* Sets Flags for DFU Triggering */
uint8_t reg_val = nrf_power_gpregret_get();
reg_val = reg_val | 0xB1; /* Set bit 1 to triger DFU */

vTaskDelay(10);
nrf_power_gpregret_set(reg_val);

The system hangs instead of starting the bootloader. No led toggles, no Advertising. Upon power reset the Application starts

RE: System hangs switching from Application to Bootloader

Edvin — Tue, 12 May 2020 08:35:30 GMT

[quote user="Edvin Holmseth"]Can you please try to use the bootloader project found in pca10040_ble_debug, and monitor the RTT log when you try to enter the bootloader?[/quote]

RE: System hangs switching from Application to Bootloader

Locky — Mon, 11 May 2020 18:55:32 GMT

When I program the softdevice and my bootloader or the example bootlaoder everything runs fine and the Application updates and runs. But when I try and trigger a DFU update from the Application, everything freezes again after the sd_nvic_SystemReset(). I added a delay after setting the retention register (though I've never had to do this before) but the effect is the same.

I suspect there are two possible issues. Either for some reason the MBR doesn't contain the right vector to jump to the bootloader, or somehow the bootloader gets corrupts upon Application update.

RE: System hangs switching from Application to Bootloader

Edvin — Mon, 11 May 2020 11:43:05 GMT

Hello,

Can you please try to use the bootloader project found in pca10040_ble_debug, and monitor the RTT log when you try to enter the bootloader?

The log from the bootloader may say something about why it stops.

Either, the bootloader is not started properly, because of a bug there, or if the register is not set correctly, or it restarts the application, but this crashes, causing you to have an infinite app_error->reboot loop.

Did you do any changes in the bootloader project?

Have you checked out the ble_app_buttonless_dfu example in the SDK, which has a separate BLE service to put the device in DFU mode? You can see there how it tells the bootloader to stay in DFU mode on the next reset.

Perhaps you don't wait long enough between the nrf_power_gpregret_set() and sd_nvic_SystemReset()? I suspect this is the case if the implementation is like you describe in the snippet, with nothing else in between.

Try to add a few ms of delay before you reset, so that the register has time to be written before you reset.

BR,

Edvin