SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
When the device is set to boot through the Ethernet mode, the ROM Code configures the Ethernet module and the interface mode (RMII, RGMII) according the the BOOTMODE pin settings, see Section 4.4.5, Ethernet Boot Device Configuration. Also consult the boot parameter table for the Ethernet boot, see Section 4.6.8, Ethernet Boot Parameter Table.
When Link Info = 0, the link parameters are read using MDIO scan. This is the typical setting when using an external PHY. When Link Info = 1, no MDIO scan is performed, and the link parameters are programmed by the ROM based on the RGMII status register.
Note that booting from RGMII requires that an attached PHY be configured for RGMII-ID Mode immediately upon exiting reset. The ROM will not make this configuration change to the PHY.