| 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 CONFIG_SYS_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. |