Using QSPI Flash for MIMXRT555 developement

[GR-Grinn]

Hi!

We want to use MIMXRT555SFAWCR in a product based on Zephyr RTOS. To start development we're using MIMXRT595-EVK.

Given the lack of all OSPI signals in the selected MCU we're forced to use QSPI Flash memory. Even if we switch the EVK to QSPI Flash there seem to be no support for it in the Zephyr. MCUXpresso also does not seem to have a lot of support for this use case.

1. What is the suggested way of developing application for MIMXRT555SFAWCR using the only available MIMXRT500 family development kit: MIMXRT595-EVK?
2. Is it even possible to use QSPI Flash memory under Zephyr?
3. Are there any additional materials that we can reference during development regarding QSPI usage and configuration?

[GR-Grinn]

Thank you for your response @Gavin_Jia!

One of our RT595_EVK boards is already configured to be used with QSPI Flash. Hardware modifications and boot setup were also applied and tested with MCUxpresso hello world sample running from the QSPI.

I cannot find any DTS node in the Zephyr source code for the QSPI Flash installed on the evaluation kit (IS25WP064AJBLE), and the driver (flash_mcux_flexspi_nor.c) seems to only enable quad mode for MX25 family of Flash chips base on runtime detection: https://github.com/zephyrproject-rtos/zephyr/blob/main/drivers/flash/flash_mcux_flexspi_nor.c#L890C2...

Even if boot-related configuration would be enough for the code to run in the XIP mode, any feature requiring access to Flash memory in our application (e.g. storage and DFU, or not using XIP mode) seems to be impossible without adding DTS node, and performance would be impacted without modifying the driver.

Is there anything that we are missing? Right now we're looking into replacing the QSPI Flash on the evaluation kit with one of the Macronix Flash memories, that seem to be supported, as this is the memory that we are going to use on our custom PCB.

With regards

[Gavin_Jia]

Hi @GR-Grinn ,

Thanks for your interest in NXP MIMXRT series!

First of all, although there is no more information available, it is possible to develop using QSPI Flash in Zephyr. For more information on how to use QSPI Flash on the RT595_EVK, NXP provides this document for reference: Boot from QSPI Flash on MIMXRT595-EVK (nxp.com)

If your board runs according to this documentation, then it's time to try the Zephyr project. It hasn't been verified, but my guess is that the required changes on the software side are essentially the same.（FDCB header\FlexSPI frequency\Flash Driver）

Best regards,
Gavin