Secure DFU over UART issue

RE: Secure DFU over UART issue

Hung Bui — Wed, 27 Jun 2018 17:44:38 GMT

I don't think we have document on it. The MBR code is not open. But what exactly you want to do with the MBR parameter page ?

Usually that page is used to store information about the location of the new softdevice/ bootloader and which command the MBR need to do on the next reset, just in case the DFU process got interrupted by a power failure for example.

RE: Secure DFU over UART issue

Sridhar Jonnavittula — Wed, 27 Jun 2018 17:15:55 GMT

Can you point me guide or document for this

You mean the one inside the MBR or the one inside the bootloader?

RE: Secure DFU over UART issue

Hung Bui — Wed, 27 Jun 2018 15:30:14 GMT

It's normal to have data copied twice. It's dual bank bootloader. The image is copied to a swap area first, then the swap area is verified (with CRC) after that it will be copied to the correct location. This is to avoid bricking the device if there is a corruption when sending the image, so you can always fallback to the original application.

I'm not sure which MBR parameter page you are looking for ? You mean the one inside the MBR or the one inside the bootloader ? You shouldn't have to worry about that page as it's for internal use between the bootloader and the MBR.

RE: Secure DFU over UART issue

Sridhar Jonnavittula — Tue, 26 Jun 2018 17:54:00 GMT

Hi Hung Bui,

The first reply is given by me by changing sd_req to 0xA9 and it was working. But from that screenshot you can see that same image is copied twice i.e 0x26000-0x345c4, 0x35000-0x435c4 and is this expected scenario? I think image should be present only at one memory rage 0x26000-0x345c4. And the same is observed when mbr without softdevice and any hardware peripheral example is tested over serial link.

Also MBR parameter page is not created. Please let me know why it is not created?

Thanks

RE: Secure DFU over UART issue

Hung Bui — Tue, 26 Jun 2018 16:03:57 GMT

Hi,

Could you clarify that by setting the sd_req you can do UART DFU properly ?

From the screenshot you provided, it seems that the bootloader receives the image, however the image was not verified and it's not copied into flash and the bootloader stay in bootloader mode without jumping to the application (because the application was invalid). This is dual bank DFU.

In the second case the image was copied properly.

RE: Secure DFU over UART issue

Sridhar Jonnavittula — Tue, 26 Jun 2018 11:07:51 GMT

Hi,

This screenshot is when bootloader settings page is generated with sd_req as 0xA9 and it is the only change as referred from http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.0.0%2Flib_bootloader_dfu_validation.html&anchor=lib_dfu_image Updates without a softdevice section. So this way updated example runs but my question is why two times example is updated in two different successive memory locations. Is this expected?

Thanks