Hi,

In ARM TBBR, there is a requirement

“R0100_TBBR_AFM_FLASHING” (The AP firmware must switch to the Non-Trusted world for executing the SoC firmware loader),

But there is no requirement for secure boot as long as I finish chain if ROT verification.

So, can I implement FWU in BL2 which is verified and load from BL1 (ROM)?

For example,

   BL1(ROM) -> Load and verify BL2U with new image from SD to secure RAM -> execute BL2U in Secure RAM then write new image to NAND flash

Best regards,

Jun