PROCESSOR-SDK-AM62A: Testing the backup keys for secure boot

Tool/software:

Hi,

I'd like to test using the custom bmpk.pem that was programmed into our hs-se device. After looking over some threads, it looks like the keyrev has to be changed to "2" to activate the backup keys.

What happens if smpk.pem is lost before the board's keyrev is changed, is there any use for bmpk.pem?

Is this conversion done through the same sbl_keywriter tool I initially used in the mcu sdk?

Would the conversion image have to be signed by the original keys also so the board accepts it?

Can you please share how to use the backup keys if I'm using mcu_plus_sdk_am62ax_09_00_00_19. I followed the AM62AX_OTP_Keywriter_User_Guide to initially program smpk and bmpk keys to the board. I'm reading over this FAQ but I'm not sure if these same steps apply to me.

e2e.ti.com/.../faq-am6442-am243-how-to-use-the-tisci-apis-read_keycnt_keyrev-write_keyrev-to-activate-the-backup-key-set

Thanks,

Joseph