In T2080 RM, REV 4, Page 230, It mentioned that:
IFC FCM (NOR flash) does not require initialization by the PBL even though it
can be selected as the source for the RCW or PBI commands.
But how the communication happens between Processor and NOR flash device if IFC is not initialized
The reset controller performs reset initialization of the IFC. Only chip-select CS0 is used for booting. You can find in the manual that IFC registers related to the CS0 have special reset settings if the IFC is used for booting from NAND or NOR. See for example 13.3.3 Chip-select Property register .