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Diffstat (limited to 'qemu/roms/u-boot/doc/README.silent')
| -rw-r--r-- | qemu/roms/u-boot/doc/README.silent | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/doc/README.silent b/qemu/roms/u-boot/doc/README.silent new file mode 100644 index 000000000..6d90a0ec4 --- /dev/null +++ b/qemu/roms/u-boot/doc/README.silent @@ -0,0 +1,28 @@ +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. |