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authorAngelos Mouzakitis <a.mouzakitis@virtualopensystems.com>2023-10-10 14:33:42 +0000
committerAngelos Mouzakitis <a.mouzakitis@virtualopensystems.com>2023-10-10 14:33:42 +0000
commitaf1a266670d040d2f4083ff309d732d648afba2a (patch)
tree2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/doc/README.silent
parente02cda008591317b1625707ff8e115a4841aa889 (diff)
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+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
+ enabling CONFIG_SYS_DEVICE_NULLDEV in your board defconfig 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.