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". - CONFIG_SILENT_CONSOLE_UPDATE_ON_SET When the "silent" variable is changed with env set, the change will take effect immediately. - CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC Some environments are not available until relocation (e.g. NAND) so this will make the value in the flash env take effect at relocation. 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. If you don't want the linux command line to be affected, define CONFIG_SILENT_U_BOOT_ONLY in your board config file as well, and this part of the feature will be disabled.