The config option CONFIG_SILENT_CONSOLE can be used to quiet messageson the console.  If the option has been enabled, the output can besilenced by setting the environment variable "silent".  The variableis latched into the global data at an early stage in the boot processso deleting it with "setenv" will not take effect until the system isrestarted.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.