How to Run an NRF Connect SDK App from External Flash (XIP) for NRF52840 chip

[AhmedPs19]

Hello Team,

Just to give you a background , I am working on a project using the NRF Connect SDK and want to run my application from external flash memory. Specifically, I am trying to replicate the functionality of the blinky_systick example from NRF SDK 17, which runs from external flash.

Problem: I am unsure about the steps required to configure my NRF Connect SDK app to run from external flash. I need guidance on the necessary configurations and modifications.

Attempts: I have reviewed the blinky_systick example in NRF SDK 17 and tried to adapt its settings to my NRF Connect SDK project. However, I am facing difficulties in understanding the correct procedure and necessary modifications. I have looked through the NRF Connect SDK documentation but could not find a clear guide on this topic for NRF52840 soc.

What steps should I take to configure and run an NRF Connect SDK application from external flash memory, similar to the blinky_systick example in NRF SDK 17? Could you provide a detailed guide or point me to relevant documentation?

Kind regards,

Ahmed

[Vidar Berg]

Hello,

Unfortunately, the code examples we have with XiP are configured for the nRF5340 (Code relocation nocopy, SMP Server with external XIP). The [216] QSPI: Race condition occurs in XIP errata limits the usability of XiP on the 52840. Simple examples such as blinky_systick will work fine, but it stops working when you start including drivers with interrupts enabled, etc.

Best regards,

Vidar

[AhmedPs19]

Vidar,

Can you tell me steps to change the flash address in Nrf connect SDK because I think it does not use the regular .ld files predefined. Linker.cmd file is generated at the build time , I am not sure where it is getting values for that file.

Regards,

Ahmed

[Vidar Berg]

The memory placement is defined by the partitions specified in your DeviceTree or Partition Manager if you are building with the bootloader. However, as I mentioned in my first reply, running the Zephyr application from the external flash is likely not going to work due to said errata. Additionally, the execution performance will prevent you from running things such as the Bluetooth controller.