This is currently implemented in net/eth.c
Look in include/net.h for details.
+config PHYLIB
+ bool "Ethernet PHY (physical media interface) support"
+ help
+ Enable Ethernet PHY (physical media interface) support.
+
menuconfig NETDEVICES
bool "Network device support"
depends on NET
if NETDEVICES
+config E1000
+ bool "Intel PRO/1000 Gigabit Ethernet support"
+ help
+ This driver supports Intel(R) PRO/1000 gigabit ethernet family of
+ adapters. For more information on how to identify your adapter, go
+ to the Adapter & Driver ID Guide at:
+
+ <http://support.intel.com/support/network/adapter/pro100/21397.htm>
+
+config E1000_SPI_GENERIC
+ bool "Allow access to the Intel 8257x SPI bus"
+ depends on E1000
+ help
+ Allow generic access to the SPI bus on the Intel 8257x, for
+ example with the "sspi" command.
+
+config E1000_SPI
+ bool "Enable SPI bus utility code"
+ depends on E1000
+ help
+ Utility code for direct access to the SPI bus on Intel 8257x.
+ This does not do anything useful unless you set at least one
+ of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
+
+config CMD_E1000
+ bool "Enable the e1000 command"
+ depends on E1000
+ help
+ This enables the 'e1000' management command for E1000 devices. When
+ used on devices with SPI support you can reprogram the EEPROM from
+ U-Boot.
+
config ETH_SANDBOX
depends on DM_ETH && SANDBOX
default y
100Mbit and 1 Gbit operation. You must enable CONFIG_PHYLIB to
provide the PHY (physical media interface).
+config PCH_GBE
+ bool "Intel Platform Controller Hub EG20T GMAC driver"
+ depends on DM_ETH && DM_PCI
+ select PHYLIB
+ help
+ This MAC is present in Intel Platform Controller Hub EG20T. It
+ supports 10/100/1000 Mbps operation.
+
endif # NETDEVICES