Slow boot of encrypted image from SDRAM

[petar_lalov]

Hi,

I observe that booting an encrypted image from SDRAM takes 45 seconds for about 2.5 MB. When I boot it as signed, it starts almost instantly - about 1 second. I am creating the image and flashing it with the MCUXpresso Secure Provisioning Tool v6.

The platform is:

• RT1064 (uCOM Board - EmbeddedArtists.com)
• External RAM - 32 MB SDRAM
• The main part of the firmware/image is GUI (LVGL)
• The firmware is run from SDRAM
• The firmware image is stored inside RT1064 - QSPI

I have tried to solve it but with no result. One thing is obvious - smaller encrypted image results in better boot time. I found nothing relevant on the internet, and I believe I am either doing something wrong or this timing is expected.

I would be glad for any advice or pattern to solve this issue.

Thank you.

[Omar_Anguiano]

Hello, I hope you are well.

It is expected that a encrypted and signed image consumes more time on booting, depending the size of the image this time will increment however I found 45 second odly as it is too much time even for encrypted image. 

How you encrypted the image? Could you provide the steps followed or could you provide the a test code to reproduce it on the EVK?

Best regards,
Omar