Boot flow about Recovery mode

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Hi NV pals,
Platform: jetson-tx2

Because I want to enable secure boot and burn fuses
I need to check following issue to avoid flash( eMMC ) rework.

TX2’s booting process,

BootROM->MB1-> MB2-> Cboot-> Uboot-> kernel.

  1. RCM is on BootROM process?
  2. I can always enter RCM always no matter enable secure boot or not?
  3. I can always re-flash eMMC no matter enable secure boot or not ?
2

hello ykei007,

your understanding of the booting process is correct,
suggest you also check the documentation, Jetson TX2 Boot Flow.

there’re two different scenario regarding to RCM,
1. if the board is un-fused
no key should be provided to flashing tools.
then, tools will handle as zero-sbk. RCM components contain only AES hash.
2. if the board is fused
private key needs to be provided to flashing tools so that RCM components will be signed properly.
since RCM code will be signed as long as secure boot is enabled so it should be secure as other signed component like BCT or bootloader.

please download Secure Boot package via download center, you should also read README_secureboot.txt for the steps to enable secure boot.
you might also access Tutorials page, expand [Developer Tools] session, check [Jetson Security and Secure Boot] training video to have more details.
thanks

3

Hi Jerry,
Thanks for your reply.

I had read document you suggest before.
for 2. if the board is fused
So I only keep the 2k RSA private key used to burn fuse and sign boot files
It will be no risk for device to do hardware rework(remount eMMC)???

4

hello ykei007,

due to eMMC also contains 2048-bit public key and signature of BCT and bootloader, which were used for software authentication to booting the device.
once the board is fused, replacing eMMC should be a risk.
thanks