pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes when I

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

Hung Bui — Wed, 10 Oct 2018 11:48:14 GMT

Yeah, I think you are on the right track. Let us know (by creating new question) if you have any problem.

Happy coding :)

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

uhrheber — Wed, 10 Oct 2018 08:23:18 GMT

You're right.

I wasn't planning on buying one, because I thought that I would mostly play around with micropython, and only a little bit of C, but it now seems that I have to fully dive into SDK and bootloader development, so I folded and ordered one.

I already had ordered a full J-Link, because I always wanted one.

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

Hung Bui — Tue, 09 Oct 2018 15:25:20 GMT

I see your point. But in my opinion it's worth it to get a nRF52DK. You have full GPIO, NFC, LED to play with. And please be aware that you can use the nRF52DK as a Jlink programmer to flash the dongle.

You can get the nRF52DK as low as $39.

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

uhrheber — Tue, 09 Oct 2018 12:17:28 GMT

Hung,

I already imagined, that you signed the bootloader to prevent accidential overwriting.

But:

- It would've been nice if you told us that in the documentation

- it would've been even nicer if you gave us the key

Don't get me wrong, It's very kind of you to sell this dongle at that incredibly low price. I bought 5 of them, because I'm a hardware guy, and connect lots of things to microcontrollers, so I break some here and there. At that price, I don't even bother replacing a damaged micro.

I have a ton of different programmers and debuggers here, but unfortunately no J-Link (yet).

I might buy a nRF52 DK, if I keep developing for nRF52. I could also use an OpenOCD programmer, like the BlackMagicProbe, to flash the bootloder, but for that I would have to dig into the memory layout of the nRF52840 in detail, and I just didn't have the time for this.

But, there are a lot of people that are just starting into the world of microcontrollers, and can afford a nRF52840 dongle, but not a J-Link programmer. This dongle is, just to name an example, a good device to start with Micropython or Circuitpython.

And it would be even better, if beginners without a programmer could replace the bootloader.

But nevermind, thanks for your effort, and have a nice day.

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

Hung Bui — Tue, 09 Oct 2018 11:25:59 GMT

Hi Uhrheber,

As you can find here: http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.2.0/ble_sdk_app_open_bootloader.html?cp=4_0_0_4_3_2

The bootloader update still requires signed package.

The reason we have this requirement is to avoid the device to be bricked by a bootloader update from 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 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.

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

uhrheber — Mon, 08 Oct 2018 17:39:36 GMT

Many thanks, I see things more clearly now.

I was able to generate a package with:

nrfutil pkg generate --hw-version 52 --sd-req 0xAE --application-version 1 --application firmware.hex firmware.zip

The softdevice was already flashed, so I could flash the package with:

nrfutil dfu usb_serial -pkg firmware.zip -p /dev/ttyACM0

And it worked.

Then I tried to update the bootloader, and generated a package with:

nrfutil pkg generate --hw-version 52 --sd-req 0xAE  --bootloader pca10059_bootloader.hex bootloader.zip --bootloader-version 1

But when trying to flash it, I got the error:

pc_ble_driver_py.exceptions.NordicSemiException: Extended Error 0x08: The init packet does not contain a signature, but this bootloader requires all updates to have one.

So, how do I add a signature?

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

Hung Bui — Mon, 08 Oct 2018 11:35:21 GMT

Hi Uhrheber,

I misread that you were using the Adafruit bootloader. It's my mistake.

Regarding the stock bootloader on the PCA10059, it's an openbootloader. You can find it in the SDK at \examples\dfu\open_bootloader\pca10059_usb

There isn't a key for the open bootloader, when you generate the .zip package for it you simply remove --key-file parameter when calling nrfjprog.

Then you can use nrfutil to update the dongle, however, I would suggest to use the nRFConnect Programmer app to do flashing for the PCA10059. You don't even need to create the .zip file, simply just choose the hex file and then flash it.

Please be aware that the PCA10059 comes with the MBR at address 0x0000 - 0x1000. And it's not possible to replace the MBR.

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

uhrheber — Fri, 05 Oct 2018 15:01:56 GMT

Sorry, I may have written this in a misleading way.

My question is not about the Adafruit bootloader, this is merely an example.

I wanted to know in general, how to overwrite the stock bootloader. And I'd like to know more about the stock bootloader. So far, I've not been able to generate a valid update packet, that your nrfutil accepts. I can flash pure hex files using the programmer app in nRF Connect, but I was never able to flash anything into the dongle using nrfutil.

So I'd like to know a little bit more about the stock bootloader. Is it's source availabe anywhere? What is it's default security key? I assume that you must use this key to generate update packages, and that nRF Connect has this key built in?

So, how do I flash the dongle using nrfutil? A working example would be highly appreciated.

Many thanks.

RE: pca10059, replacing stock bootloader with Adafruit UF2, using USB dfua signature. I can generate a zip file with nrfutil, but what key should I use? I tried to use just a private key, and flash that generated packet with nrfutil, but nrfutil crashes wh

Hung Bui — Fri, 05 Oct 2018 12:53:06 GMT

Hi Uhrheber,

Please be aware that we are not the people who make the Adafruit products or any toolchain software provided by the company.

I would suggest you to contact Adafruit to get their support.

I had a quick look at their documentation, it seems that you need to install adafruit-nrfutil instead of our nrfutil, and it seems that the tool doesn't require a private key to be provided when creating the .zip file. Most likely it's a non-secure bootloader.