Hi Murad,
IBL supports three I2C boot modes: NOR boot, NAND boot and EMAC boot.
Both NOR boot and NAND boot support maximum 2 images, EMAC boot supports only 1 image.
For all the I2C boot modes, user needs to set the boot dip switches to I2C master, bus address 0x51.
The usage of IBL is documented in below link.
ROM Boot modes (such as Ethernet, SRIO, PCIe, SPI etc.) which address the boot source directly from the ROM code.