Low power boot M33 iMX93

[CambridgeDev]

Hi,

I'm trying to get Zephyr to boot on the M33 core on a phytec Nash iMX93 board. So far I have managed to:

• Build hello-world from the MCUXpresso SDK
• Used imx-mkimage to create a flash.bin for the iMX93 low power boot
• Written flash.bin to an SD card using dd
• Set the Nash board to low power boot from SD card mode

This worked (first time!) and I can see the hello world output on the UART2 VCOM.

I then built the Zephyr hello-world sample for phyboard_nash/mimx9352/m33, and followed the same steps as above to get a flash.bin on the SD card.

Unfortunately, this doesn't seem to work - I was expecting (hoping) to see the Zephyr boot messages on UART2, but no luck. 

Can anyone help me with this ? The examples I've found all start Zephyr on the M33 from Linux on the A5s, which I don't want. We need to boot into Zephyr on the M33, and then start Linux from Zephyr.

TIA

[JosephAtNXP]

Hi,

Thank you for your interest in NXP Semiconductor products,

Please refer to the following link, zephyr needs to be booted over U-boot either from DDR or TCM.

Regards

[CambridgeDev]

Hi Joseph

Thanks for the response.

In general, Zephyr does not require a bootloader, and can be booted from bare metal.

In the link you posted it says:

To make a container image flash.bin with zephyr.bin for SD/eMMC programming and booting from BootROM. Refer to user manual of i.MX93 MCUX SDK release.

This is what we are trying to do.

Following the SDK guidance for creating a flash.bin container works for the hello_world SDK example; the M33 ROM boot code can load and run the program.

However, building a container image in the same way does not work for our zephyr.bin.

Please could you provide guidance on how to build a container with zephyr.bin that the M33 boot rom code an load and run. We don't have any security requirements at this point.

Thanks.