The config option CONFIG_SILENT_CONSOLE can be used to quiet messages on the console. If the option has been enabled, the output can be silenced by setting the environment variable "silent". The variable is latched into the global data at an early stage in the boot process so deleting it with "setenv" will not take effect until the system is restarted. The following actions are taken if "silent" is set at boot time: - Until the console devices have been initialized, output has to be suppressed by testing for the flag "GD_FLG_SILENT" in "gd->flags". - When the console devices have been initialized, "stdout" and "stderr" are set to "nulldev", so subsequent messages are suppressed automatically. Make sure to enable "nulldev" by #defining CFG_DEVICE_NULLDEV in your board config file. - When booting a linux kernel, the "bootargs" are fixed up so that the argument "console=" will be in the command line, no matter how it was set in "bootargs" before.