| wdenk | f72da34 | 2003-10-10 10:05:42 +0000 | [diff] [blame] | 1 | The config option CONFIG_SILENT_CONSOLE can be used to quiet messages |
| 2 | on the console. If the option has been enabled, the output can be |
| Joe Hershberger | e080d54 | 2012-12-11 22:16:30 -0600 | [diff] [blame] | 3 | silenced by setting the environment variable "silent". |
| 4 | |
| 5 | - CONFIG_SILENT_CONSOLE_UPDATE_ON_SET |
| 6 | When the "silent" variable is changed with env set, the change |
| 7 | will take effect immediately. |
| 8 | |
| 9 | - CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC |
| 10 | Some environments are not available until relocation (e.g. NAND) |
| 11 | so this will make the value in the flash env take effect at |
| 12 | relocation. |
| wdenk | f72da34 | 2003-10-10 10:05:42 +0000 | [diff] [blame] | 13 | |
| 14 | The following actions are taken if "silent" is set at boot time: |
| 15 | |
| 16 | - Until the console devices have been initialized, output has to be |
| 17 | suppressed by testing for the flag "GD_FLG_SILENT" in "gd->flags". |
| wdenk | f72da34 | 2003-10-10 10:05:42 +0000 | [diff] [blame] | 18 | |
| 19 | - When the console devices have been initialized, "stdout" and |
| 20 | "stderr" are set to "nulldev", so subsequent messages are |
| 21 | suppressed automatically. Make sure to enable "nulldev" by |
| Simon Glass | 7e15638 | 2020-08-11 11:23:36 -0600 | [diff] [blame] | 22 | enabling CONFIG_SYS_DEVICE_NULLDEV in your board defconfig file. |
| wdenk | f72da34 | 2003-10-10 10:05:42 +0000 | [diff] [blame] | 23 | |
| 24 | - When booting a linux kernel, the "bootargs" are fixed up so that |
| 25 | the argument "console=" will be in the command line, no matter how |
| Joe Hershberger | be2e5a0 | 2013-02-27 10:20:59 +0000 | [diff] [blame] | 26 | it was set in "bootargs" before. If you don't want the linux command |
| 27 | line to be affected, define CONFIG_SILENT_U_BOOT_ONLY in your board |
| 28 | config file as well, and this part of the feature will be disabled. |