Jumping to Bootloader from the Application

[rabiaasl]

How can I jump to the bootloader from the application without anything BLE related. Possibly through a botton?

I'm on the newest SDK v11.

[bjorn-spockeli]

In order to jump to the bootloader , you have to add this define in your application project

#define BOOTLOADER_DFU_START 0xB1

and call the following functions when the button is pressed:

if (button_is_pressed)

{
    //  Write to the the GPREGRET REGISTER and reset the chip

   //You can use the sd_-functions 

    err_code = sd_power_gpregret_set(BOOTLOADER_DFU_START);

    APP_ERROR_CHECK(err_code);

    sd_nvic_SystemReset();   


   //OR set the register directly and then call NVIC_SystemReset(); 

    NRF_POWER->GPREGRET = BOOTLOADER_DFU_START;

    NVIC_SystemReset();
}

In the bootloader you have to remove the init_softdevice check in ble_stack_init(), i.e.

//if (init_softdevice)

//{
    err_code = sd_mbr_command(&com);

    APP_ERROR_CHECK(err_code);
//}

-Bjørn

[bjorn-spockeli]

No, you can write to the GPREGRET (General purpose retention register) at any time and set it to any value. No, writing to the GPREGRET register does not have to be followed by a reset. Since the register is retained during a reset, you can set it to a certain value indicating the reason for the reset and then check it after the device has reset. We do not have any documentation on how to use GPREGRET register.