Doubts about Bootloader

[tuxd3v]

Hello all,
I have tried to build Rockpro64 bootloader..

But I am still confused with the methodology/ tools used..

I am using ATF mainline + u-Boot..
But it seems that the boards uses OPTEE Trusted Execution Environment instead of ATF?

Is this scheme bellow correct?

Code:

+--------+----------------+----------+-------------+---------+
| Boot   | Terminology #1 | Actual   | Rockchip    | Image   |
| stage  |                | program  |  Image      | Location|
| number |                | name     |   Name      | (sector)|
+--------+----------------+----------+-------------+---------+
|        |                |          |             |         |
| 2      |  Secondary     | U-Boot   |idbloader.img| 0x40    | pre-loader
|        |  Program       | TPL/SPL |             |         |
|        |  Loader (SPL)  |          |             |         |
| 3      |  -             | U-Boot | u-boot.itb  | 0x4000  | including u-boot and atf
|        |                |          |             |         |
| 4      |  -             | /boot  | boot.img    | 0x8000  |
|        |                |          |             |         |
| 5      |  -             | /  | rootfs.img  | 0x40000 |
+--------+----------------+----------+-------------+---------+

Does I need OPTEE 'tee.bin'( renamed as bl31.elf )??

I am already using ARM Trusted Firmware bl31.elf..
Can somebody help me?

Thanks in Advance,
Best Regards
tux