From: Adam Simonelli <adamsimonelli@xxxxxxxxx>
The new config option, CONFIG_NULL_TTY_DEFAULT_ CONSOLE will allow
ttynull to be initialized by console_initcall() and selected as a
possible console device.
Signed-off-by: Adam Simonelli <adamsimonelli@xxxxxxxxx>
---
drivers/tty/Kconfig | 15 ++++++++++++++-
drivers/tty/ttynull.c | 11 +++++++++++
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index 63a494d36a1f..868aec2ccbb3 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -383,7 +383,20 @@ config NULL_TTY
available or desired.
In order to use this driver, you should redirect the console to this
- TTY, or boot the kernel with console=ttynull.
+ TTY, boot the kernel with console=ttynull, or enable
+ CONFIG_NULL_TTY_DEFAULT_CONSOLE.
+
+ If unsure, say N.
+
+config NULL_TTY_DEFAULT_CONSOLE
+ bool "Support for console on ttynull"
+ depends on NULL_TTY=y && !VT_CONSOLE
+ help
+ Say Y here if you want the NULL TTY to be used as a /dev/console
+ device.
+
+ This is similar to CONFIG_VT_CONSOLE, but without the dependency on
+ CONFIG_VT. It uses the ttynull driver as the system console.
If unsure, say N.
diff --git a/drivers/tty/ttynull.c b/drivers/tty/ttynull.c
index d8b51edde628..cb1e363b726d 100644
--- a/drivers/tty/ttynull.c
+++ b/drivers/tty/ttynull.c
@@ -96,6 +96,17 @@ static int __init ttynull_init(void)
return 0;
}
+#ifdef CONFIG_NULL_TTY_DEFAULT_CONSOLE
+static int __init ttynull_register(void)
+{
+ if (!console_set_on_cmdline)
+ add_preferred_console("ttynull", 0, NULL);;
+
+ return 0;
+}
+console_initcall(ttynull_register);
+#endif
+
static void __exit ttynull_exit(void)
{
unregister_console(&ttynull_console);
--
2.45.2
