Verify Ethernet Driver in U-Boot

This section provides procedures for verifying that MAC-PHY data path is functional in U-Boot.

Set up Network Environment Variables

Before testing Ethernet functionality in U-Boot, configure the required environment variables. U-Boot operates a single Ethernet interface at a time, so you must specify which interface and address to use.

ipaddr: Board IP address on the local network
ethact: Active Ethernet interface
ethaddr: MAC address of the active interface

For example:

 setenv ipaddr 192.168.120.230
setenv ethact ethernet@16030000
setenv ethaddr 6c:cf:39:7c:4e:22

To verify the current environment settings:

printenv ipaddr ethact ethaddr

Boot Log Verification

After adding or modifying the Ethernet driver, power cycle the board and examine the boot log for the second U-Boot access (the first boot initializes hardware).

For example, in the following log, the highlighted information indicates that

Verify PHY Access with MDIO

Verify PHY connectivity using MDIO commands. This examines whether the PHY is ready for data communication.

mdio list
mdio read <phy_addr> <reg>
mdio write <phy_addr> <reg> <value>

For example, to read PHY ID from address 0:

mdio read 0 2
mdio read 0 3

Test Digital Loopback

Perform a loopback test to verify TX and RX functionality:

setenv ipaddr 192.168.1.100
ping $ipaddr