[coreboot] Porting coreboot to new board

[Zvi Vered]

Hello,

I have to port coreboot to a new "Mainboard" not listed in menuconfig.
Is there a basic "Mainboard" I should use as a starting point that will be
copied to my board ?

The file board_info.txt contains few parameters.
How can I know the meaning of each parameter and its possible values ?

The board kontron/kt690 for example contains few files like: cmos.layout,
devicetree.cb, etc
Are all those files mandatory ?
Is there a list of mandatory files or routines required in order to port a
board ?

Your help is highly appreciated.
Best regards,
Zvika