Direct XIP + External QSPI

RE: Direct XIP + External QSPI

Roedy — Wed, 14 Aug 2024 14:19:26 GMT

Yes, It worked perfectly! When I corrupted the primary image, mcuboot only finds the secondary and boots into it.

RE: Direct XIP + External QSPI

Sigurd Hellesvik — Wed, 14 Aug 2024 10:35:42 GMT

MCUboot does not have any logic to detect failing images and swapping, I think.

I did not think Direct-xip had this feature either, but I am unsure about this I must admit.

Did you test the corrupting of primary slot for Direct-XIP?

RE: Direct XIP + External QSPI

Roedy — Tue, 13 Aug 2024 13:47:03 GMT

It's been a while, but if I remember correctly, I programmed the primary and secondary slots and then used nrfjprog to corrupt the primary slot. Instead of swapping, MCUBOOT just said that there were no valid images.

I think this was back in ncs 2.1.0, so things may have changed since then? Or maybe there was an mcuboot kconfig that I missed?

RE: Direct XIP + External QSPI

Sigurd Hellesvik — Tue, 13 Aug 2024 08:08:19 GMT

[quote user="Roedy"] We're using XIP because we want our application to have a backup slot that can be run if the primary slot is corrupted.[/quote]

Cant you just swap in this case?

RE: Direct XIP + External QSPI

Sigurd Hellesvik — Tue, 13 Aug 2024 08:07:16 GMT

[quote user="Roedy"]I think it's worth asking the question: is this even possible?[/quote]

No, you cannot run the entire secondary slot from external memory.

Some amount of code must run in internal flash, such as code in interrupt contexts.

RE: Direct XIP + External QSPI

Roedy — Mon, 05 Aug 2024 18:14:59 GMT

I think it's worth asking the question: is this even possible? The example and documentation https://docs.nordicsemi.com/bundle/ncs-2.6.0/page/nrf/device_guides/working_with_nrf/nrf53/qspi_xip_guide.html seems to suggest that external XIP is for relocating *some* of the code into external flash.

I want the *entire* secondary slot XIP from external memory. Our system has some unique constraints. We're using XIP because we want our application to have a backup slot that can be run if the primary slot is corrupted. Using just the primary flash, this works as expected but we're running out of space, which is why we want the secondary slot in external.

In addition, we have some product requirements that would make it very tough for us to break the application up into internal/external portions of a single slot as demonstrated in the extxip_smp_svr example.

RE: Direct XIP + External QSPI

Charlie — Mon, 05 Aug 2024 14:24:33 GMT

Hi Roedy,

Thanks for checking with us about this issue. Just let you know I am looking at this case now.

I will give it a try later to see if I can repeat this issue.

Best regards,

Charlie