This sections that follow describe the interactions between the IF layer, the Ethernet device driver API functions, the BSP API functions and the Ethernet PHY API functions. Since the device driver is made of not only logic but also from interactions with the parts on the board, you'll need to understand the calls made to the these layers of the µC/TCP-IP module and to the CPU and board-dependent layers.
Figure 7-5 shows the logical path between the physical layer and the device driver through the function calls and interruptions.