AM625: AM625 boot fail with FDT_ERR_NOTFOUND

Part Number: AM625

Dear TI.

I'm verifying TI secure boot with AM625-SK EVM

I succeeded to change device type to HSSE like below

-----------------------
SoC ID Header Info:
-----------------------
NumBlocks            : 2
-----------------------
SoC ID Public ROM Info:
-----------------------
SubBlockId           : 1
SubBlockSize         : 26
DeviceName           : am62x
DeviceType           : HSSE
DMSC ROM Version     : [0, 1, 0, 1]
R5 ROM Version       : [0, 1, 0, 1]
-----------------------
SoC ID Secure ROM Info:
-----------------------
Sec SubBlockId       : 2
Sec SubBlockSize     : 166
Sec Prime            : 0
Sec Key Revision     : 1
Sec Key Count        : 2
Sec TI MPK Hash      : d68ecb2c055dff11ade95bd927e837d2a53bc23b0a2800cebce4f106bcf309df2213912d77a157a8b7c2df40672a06a918034aa4c7d603e462481475225d49b8
Sec Cust MPK Hash    : 1f6002b07cd9b0b7c47d9ca8d1aae57b8e8784a12f636b2b760d7d98a18f189760dfd0f23e2b0cb10ec7edc7c6edac3d9bdfefe0eddc3fff7fe9ad875195527d
Sec Unique ID        : c090e3c49076ef1bfab52a03204c9df515e10237962b22e0c8c2fe099281ac1a

Then I changed tiboot3-am62x-hs-evm.bin  to tiboot3.bin and tried to boot, but it failed with FDT_ERR_NOTFOUND.

I checked below link but I could not fully understand the process to make fitImage.

software-dl.ti.com/.../Foundational_Components_Kernel_Users_Guide.html

In "3.2.1.6.2. Generating the fitImage", it describes some changes for signing a secondary platform.

What does a secondary platform mean? Should I apply the similar change for AM625-SK EVM ?

FYI, I'm using ti-processor-sdk-linux-am62xx-evm-09.02.01.09

And It also requests to execute below command.

mkimage -r -f fitImage.its -k $UBOOT_PATH/arch/arm/mach-k3/keys -K $UBOOT_PATH/build/$ARMV8/dts/dt.dtb fitImage

But I could not find fitImage.its in SDK.
And I could not fild  $UBOOT_PATH/build/ folder in ti-processor-sdk-linux-am62xx-evm-09.02.01.09

Could you guide me to generate fit image with ti-processor-sdk-linux-am62xx-evm-09.02.01.09 ?

BR
Jace