On the enbw_cmc board is a KSZ8864RMN switch which needs configured through spi before working. This is done on startup from u-boot through a config file stored at an address specified in the "hwconfig" environment variable, subcommand "config". For example on the enbw_cmc board: hwconfig=switch:lan=on,pwl=off,config=0x60160000 The file has the following structure: - a comment starts with a '#' or a ';' and ends with a newline - The switch needs for its config a reg/value pair, so we have two columns in the file: reg : contains the register address value: contains a 8 bit register value This 2 columns are seperated through space or tab. example (minimal configuration on the enbw_cmc board): ;reg value comment ;----------------------------------------- 0x01 0x00 0x01 0x01 ; Start Switch with this configuration