1f72da340SwdenkThe config option CONFIG_SILENT_CONSOLE can be used to quiet messages 2f72da340Swdenkon the console. If the option has been enabled, the output can be 3e080d545SJoe Hershbergersilenced by setting the environment variable "silent". 4e080d545SJoe Hershberger 5e080d545SJoe Hershberger- CONFIG_SILENT_CONSOLE_UPDATE_ON_SET 6e080d545SJoe Hershberger When the "silent" variable is changed with env set, the change 7e080d545SJoe Hershberger will take effect immediately. 8e080d545SJoe Hershberger 9e080d545SJoe Hershberger- CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC 10e080d545SJoe Hershberger Some environments are not available until relocation (e.g. NAND) 11e080d545SJoe Hershberger so this will make the value in the flash env take effect at 12e080d545SJoe Hershberger relocation. 13f72da340Swdenk 14f72da340SwdenkThe following actions are taken if "silent" is set at boot time: 15f72da340Swdenk 16f72da340Swdenk - Until the console devices have been initialized, output has to be 17f72da340Swdenk suppressed by testing for the flag "GD_FLG_SILENT" in "gd->flags". 18f72da340Swdenk 19f72da340Swdenk - When the console devices have been initialized, "stdout" and 20f72da340Swdenk "stderr" are set to "nulldev", so subsequent messages are 21f72da340Swdenk suppressed automatically. Make sure to enable "nulldev" by 226d0f6bcfSJean-Christophe PLAGNIOL-VILLARD #defining CONFIG_SYS_DEVICE_NULLDEV in your board config file. 23f72da340Swdenk 24f72da340Swdenk - When booting a linux kernel, the "bootargs" are fixed up so that 25f72da340Swdenk the argument "console=" will be in the command line, no matter how 26*be2e5a09SJoe Hershberger it was set in "bootargs" before. If you don't want the linux command 27*be2e5a09SJoe Hershberger line to be affected, define CONFIG_SILENT_U_BOOT_ONLY in your board 28*be2e5a09SJoe Hershberger config file as well, and this part of the feature will be disabled. 29