[PATCH] vt: configurable number of console devices

From: Trevor Bourget
Date: Tue May 28 2019 - 00:34:52 EST


Having 63 vt devices for embedded systems might be overkill,
so provide a configuration MAX_NR_CONSOLES to allow this
consumption to be reduced.

Signed-off-by: Trevor Bourget <tgb.kernel@xxxxxxxxx>
---
drivers/tty/Kconfig | 9 +++++++++
include/uapi/linux/vt.h | 4 ++++
2 files changed, 13 insertions(+)

diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index 3b1d312bb175..98e21589f4af 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -42,6 +42,15 @@ config VT
If unsure, say Y, or else you won't be able to do much with your new
shiny Linux system :-)

+config MAX_NR_CONSOLES
+ int "Maximum number of consoles to permit"
+ depends on VT
+ range 1 63
+ default "63"
+ ---help---
+ The maximum number of consoles that can be used.
+ The default is 63.
+
config CONSOLE_TRANSLATIONS
depends on VT
default y
diff --git a/include/uapi/linux/vt.h b/include/uapi/linux/vt.h
index e9d39c48520a..3567dd239758 100644
--- a/include/uapi/linux/vt.h
+++ b/include/uapi/linux/vt.h
@@ -8,9 +8,13 @@
* resizing).
*/
#define MIN_NR_CONSOLES 1 /* must be at least 1 */
+#ifdef CONFIG_MAX_NR_CONSOLES
+#define MAX_NR_CONSOLES CONFIG_MAX_NR_CONSOLES
+#else
#define MAX_NR_CONSOLES 63 /* serial lines start at 64 */
/* Note: the ioctl VT_GETSTATE does not work for
consoles 16 and higher (since it returns a short) */
+#endif

/* 0x56 is 'V', to avoid collision with termios and kd */

--
2.22.0.rc1.257.g3120a18244-goog