Hi @Anonymous,
I hope you are doing well.
Q1: I believe that the HAB signature verification of both the SPL Image and the FIT Image must succeed when the bootloader is started. Is this correct?
-> Yes, that is correct. Both the SPL Image and the FIT Image must have their signatures verified before the bootloader will start.
Q2.Where is SPL Image's HAB signature verification performed?
->The SPL Image's HAB signature verification is performed in the Boot ROM. The Boot ROM (a small code) that is stored in the i.MX processor's ROM. When the processor is first turned on, the Boot ROM is executed. The Boot ROM is responsible for loading the SPL Image from flash memory and verifying its signature.
Q3. Where is FIT Image's HAB signature verification performed?
->The FIT Image's HAB signature verification is performed in the u-boot-spl bootloader. u-boot-spl(a secondary program loader = BL2) is a small bootloader that is loaded by the Boot ROM. u-boot-spl is responsible for loading the u-boot bootloader from flash memory and verifying its signature.
Q4.Does it work the same even if the bootloader is started with SerialDownloader in UUU?
->Yes, the HAB signature verification process works the same even if the bootloader is started with SerialDownloader in UUU. UUU is a tool that can be used to download images to the i.MX processor's flash memory.
I hope this information helps!
Thanks & Regards,
Dhruvit Vasavada
