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| author | Randy Dunlap <rdunlap@infradead.org> | 2022-02-16 21:37:45 +0100 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2022-02-21 15:44:02 +0100 |
| commit | 96b02f2fbde29a08ac7239fd9ba87ff870cf8a94 (patch) | |
| tree | 8aedf3df826e40e903a7a494f7acac935242b2ba /Documentation/admin-guide/kernel-parameters.txt | |
| parent | printk: use atomic updates for klogd work (diff) | |
| download | linux-96b02f2fbde29a08ac7239fd9ba87ff870cf8a94.tar.xz linux-96b02f2fbde29a08ac7239fd9ba87ff870cf8a94.zip | |
Docs: printk: add 'console=null|""' to admin/kernel-parameters
Tell about 'console=null|""' and how to use it.
It can be helpful to set (enable) CONFIG_NULL_TTY so that the ttynull
driver is available. This avoids problems with stdin/stdout/stderr of
the init process. Howevere, CONFIG_NULL_TTY cannot be enabled by default
because it can be used by mistake, see the commit a91bd6223ecd ("Revert
"init/console: Use ttynull as a fallback when there is no console"").
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
[pmladek@suse.com: Slightly update wording.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220216203745.980-1-rdunlap@infradead.org
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 49f495c9a7f8..46bfadf02bc7 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -724,6 +724,12 @@ hvc<n> Use the hypervisor console device <n>. This is for both Xen and PowerPC hypervisors. + { null | "" } + Use to disable console output, i.e., to have kernel + console messages discarded. + This must be the only console= parameter used on the + kernel command line. + If the device connected to the port is not a TTY but a braille device, prepend "brl," before the device type, for instance console=brl,ttyS0 |