Bootloader - upgrading version from remote

RE: Bootloader - upgrading version from remote

Menon — Wed, 28 Jan 2026 21:57:11 GMT

Hello,

[quote user="alonmat"]I think this version is the closest to what I need[/quote]

Good to hear that.

Kind Regards,

Abhijith

RE: Bootloader - upgrading version from remote

alonmat — Tue, 27 Jan 2026 14:44:47 GMT

Yes. We are using old NRF SDK.

I already started with this example: nrf_sdk\examples\dfu\secure_bootloader\pca10056_uart

I think this version is the closest to what I need.

I will read upgrade data via UART driver which is connected to the modem.

RE: Bootloader - upgrading version from remote

Menon — Tue, 27 Jan 2026 12:14:44 GMT

Hello,
From your explanation, I guess that you are using the older nRF5 SDK is that correct? If so, I don’t think we have any samples demonstrating the use of a bootloader other than the Nordic Secure Bootloader. You can check the Bootloaders and DFU modules, also see the section open bootloaders.

Also, please note that the samples I referred to earlier are from the nRF Connect SDK, since support for cellular connectivity/modem is available only in the nRF Connect SDK.

The nRF5 SDK is currently in maintenance mode, so you may need to implement this solution on your own.

Kind regards,
Abhijith

RE: Bootloader - upgrading version from remote

alonmat — Mon, 26 Jan 2026 10:11:20 GMT

After reviewing the project again, we decided to use our Simcom modem in our device.

We already succeed to download the new firmware via http request into a file inside our simcom modem.

in the bootloader, we plan to use a UART driver to connect to the modem.

There is a modem AT command that gets the file data in chunks. We can read the chunks of data via the UART and burn the internal CPU flash

now we are using a bootloader based on the formal nrf-sdk example Secure BLE Bootloader and we burn our firmware via Phone application use BLE. We want another new similar bootloader that upgrade via modem (UART) and not use phone application at all. What is the closest example that implement this (preferably nrf-sdk example)

Best regards,

Alon

RE: Bootloader - upgrading version from remote

Menon — Mon, 19 Jan 2026 16:47:08 GMT

Hello,

We don’t have a sample that exactly matches your use case, so you may need to implement this on your own. However, there are existing samples that demonstrate using external flash as the secondary slot.

Kind Regards,

Abhijith

RE: Bootloader - upgrading version from remote

alonmat — Mon, 19 Jan 2026 14:30:11 GMT

actually I need example for bootloader with external flash. My application will download the new firmware into external flash via modem and the bootloader will copy it from external flash to the internal flash

I need example for this one. Do you have any information for how to find this example ?

RE: Bootloader - upgrading version from remote

Menon — Fri, 16 Jan 2026 11:18:10 GMT

Hello,

You can refer to the Academy course on FOTA updates. There is also an SDK sample that demonstrates serial modem firmware update, as well as serial DFU update. However, please note that these examples involve the nRF91 series, which is not applicable in your case.

Therefore, I’m not entirely sure how the implementation would apply to your specific setup.

Kind regards,
Abhijith