Kontron AM4140 U-Boot Bootloader - Manual (Page 40)

U-Boot Usage AM4140 U-Boot Bootloader
Page 40 ID 1052-0281, Rev. 1.0
P R E L I M I N A R Y
6.3.1.1 ethprime
“ethprime” is used to select the required interface after power-up or reset. During boot-up, the
U-Boot checks if “ethprime” is set. If set, “ethprime” is used as the first active Ethernet
interface (“ethact”). Please note that the setting of the “ethprime” is lost after a reset. To retain
the environment permanently, use the command “saveenv”, which saves the complete
environment to flash.
Example:
6.3.1.2 ethact
“ethact” is used to define the currently active interface and to change the required interface
without rebooting. If a reboot or a power cycle is done, the active Ethernet interface will be set
back to the interface defined in “ethprime” or selected by the “ethrotate” functionality.
Example:
6.3.1.3 ethrotate
“ethrotate” can be used to force the selection of the next available interface if, for example,
there is no link available for the selected interface.
If set to “yes” or undefined, U-Boot updates the “ethact” variable accordingly and tries to down-
load the file again. This is repeated until either the file is downloaded or all interfaces have been
exhausted.
In the event the link is active for the selected interface and “ethrotate” is “yes” or undefined, U-
Boot tries to download the file. If it cannot download the file, it tries the next available interface.
If the file is not available on the server, U-Boot stops trying and issues an error message.
If “ethrotate” is set to “no”, only the interface defined in “ethact” is used.
Please note that the setting of the “ethrotate” is lost after a reset. To retain the environment
permanently, use the command “saveenv”, which saves the complete environment to flash.
=> setenv ethprime FM1@DTSEC3
=> saveenv
Saving Environment to SPI Flash...
2 MiB
SF: Detected AT25DF161 with page size 256 Bytes, total 2 MiB
Erasing SPI flash...Writing to SPI flash...done
=> reset
...
=> printenv ethact
ethact=FM1@DTSEC3
=>
=> setenv ethact FM1@DTSEC2
=> ping 172.100.100.35
Using FM1DTSEC2 device
host 172.100.100.35 is alive
=>