Bootloader Flashing Error - Nordic NRF52840 USB Dongle

[ashokr.com]

Hi All,

Im trying to flash the pre boot-loader from here github.com/.../releases

to my nordic usb dongle.

hex-> mdk_nrf52840_dongle_bootloader-0.3.2_s140_6.1.1.hex
Im getting the DFU error.
DFU failed: Error message for known extended error code from DFU target: The init packet does not contain a signature. This bootloader requires DFU updates to be signed.

Please help on this.
Ashok R

[Amanda Hsieh]

Hi, 

DFU failed: Error message for known extended error code from DFU target: The init packet does not contain a signature. This bootloader requires DFU updates to be signed.

The bootloader update still requires a signed package. 

The reason we have this requirement is to avoid the device being bricked by a bootloader update from an untrusted source. 

Please be aware that the dongle we created to be used as a development tool, not as a development kit. So the main purpose is to be used for nRFConnect and other app. So the bootloader is not supposed to be changed. I don't think we will distribute the private key we used for the stock bootloader. 

However, if you want to change the flash it's not too difficult, you just need to solder the same header you can find on the Debug Out P19 of the nRF52 DK on to the Dongle and then use the cable to erase the chip and flash your own program. 

Please see this similar question. 

-Amanda H. 

[ashokr.com]

Hi Amanda,

Im bit confused, so you're saying its possible or not? you meant with external jlink i can flash this hex (bootloader)? where it wont as for any signed package.

Ashok R

[Amanda Hsieh]

Hi,

The nRF52840 Dongle comes preprogrammed with the Open Bootloader with DFU, which allows users to update the application firmware. However, as stated in the link above: 

• Bootloader update must come from signed packages.

We do not distribute the private key that the public key in the Open Bootloader uses, so the only way to update the bootloader on the nRF52840 dongle is to re-flash using a JLink programmer or the JLink OB programmer on a nRF52xxx DK. You will then have to solder wires to the SWDCLK and SWDIO pads on the nRF52840 Dongle or solder on a 10-pin programming header to the P1 pads. 

Please be aware that mdk_nrf52840_dongle_bootloader-0.3.2_s140_6.1.1.hex is suitable to MakerDiary NRF52840-MDK USB Dongle. You should flash pca10059_bootloader-0.3.2_s140_6.1.1.hex in your source link. See "Using an external debugger" in the nRF52840 dongle programming tutorial

-Amanda H.