Question regarding fip.bin when flashing AOSP

I have been following instructions on link to setup AOSP on the Hikey 620 board.

When I finish compiling the code, I notice that the installer folder contains a fip.bin file. My understanding is that fip.bin contains the TEE OS code. When AOSP + OPTEE manifest is used, the OPTEE compilation will be put in fip.bin. Now in the case of a clean AOSP compilation (when no OPTEE code is added), what is present in the fip.bin file ?

Thanks.

Firmware Image Package (FIP) is a packaging format used by the Arm Trusted Firmware to package firmware images in a single binary and is typically called fip.bin. Whilst OP-TEE is one of the components that can be packaged in a FIP there are other components that can be found in the FIP. For systems without a TEE this will include various bootloader components and the Arm Trusted Firmware for the platform.

@danielt Okay thank you.