README.silent 1.3 KB

12345678910111213141516171819202122232425262728
  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
  3. silenced by setting the environment variable "silent".
  4. - CONFIG_SILENT_CONSOLE_UPDATE_ON_SET
  5. When the "silent" variable is changed with env set, the change
  6. will take effect immediately.
  7. - CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC
  8. Some environments are not available until relocation (e.g. NAND)
  9. so this will make the value in the flash env take effect at
  10. relocation.
  11. The following actions are taken if "silent" is set at boot time:
  12. - Until the console devices have been initialized, output has to be
  13. suppressed by testing for the flag "GD_FLG_SILENT" in "gd->flags".
  14. - When the console devices have been initialized, "stdout" and
  15. "stderr" are set to "nulldev", so subsequent messages are
  16. suppressed automatically. Make sure to enable "nulldev" by
  17. #defining CONFIG_SYS_DEVICE_NULLDEV in your board config file.
  18. - When booting a linux kernel, the "bootargs" are fixed up so that
  19. the argument "console=" will be in the command line, no matter how
  20. it was set in "bootargs" before. If you don't want the linux command
  21. line to be affected, define CONFIG_SILENT_U_BOOT_ONLY in your board
  22. config file as well, and this part of the feature will be disabled.