Is there a way to trigger programmatically the "Serial Download" boot mode in an i.MX RT117x device?

[nicolaponzevero]

We are trying to determine if there is a way for a software running on an i.MX RT 117x to trigger the serial download mode of the processor. 

We need it to support an unexpected use case of an existing board based on an i.MX RT1175 NXP processor where

• the boot mode pins are not accessible. 
• BT_FUSE_SEL = 0
• Boot mode selection pins BOOT_MODE[1:0]=10b (Internal boot)
• Secure boot is enabled

We can consider changing the above settings and other fuses if needed, as long as the board will keep booting by default from the flash and the secure boot remains enabled.

Can you help us understanding if triggering via software the i.MX RT1175's serial download boot mode is possible and - if it is possible - describe the correct procedure to do it?

[diego_charles · Accepted solution]

Hi @nicolaponzevero 

Yes, it should be possible. You need to call the runBootloader API of the booROM. Please refer to Enter Bootloader API section of the RM. You can give paramters to the API use UART or USB.

Your code needs to include bootROM API tree structures and definitions, those are in the RM. Please Let me know if you got any issues!

Best regards, 

Diego

[nicolaponzevero]

Thanks Diego, we had misunderstood (or rather underestimated) the role of the parameters of that API, but the chapter you indicated clarified where we were wrong, allowing us to obtain what we wanted.