From: Ian Pratt <Ian.Pratt@cl.cam.ac.uk>
This patch enables the VT console to be disabled at runtime even if it is
built into the kernel. Arch xen needs this to avoid trying to initialise a VT
in virtual machine that doesn't have access to the console hardware.
Signed-off-by: Ian Pratt <Ian.Pratt@cl.cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/char/tty_io.c | 21 ++++++++++++++-------
1 files changed, 14 insertions(+), 7 deletions(-)
diff -puN drivers/char/tty_io.c~xen-vmm-4-runtime-disable-of-vt-console drivers/char/tty_io.c
--- 25/drivers/char/tty_io.c~xen-vmm-4-runtime-disable-of-vt-console 2005-02-22 18:16:26.000000000 -0800
+++ 25-akpm/drivers/char/tty_io.c 2005-02-22 18:16:26.000000000 -0800
@@ -131,6 +131,8 @@ LIST_HEAD(tty_drivers); /* linked list
vt.c for deeply disgusting hack reasons */
DECLARE_MUTEX(tty_sem);
+int console_use_vt = 1;
+
#ifdef CONFIG_UNIX98_PTYS
extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
extern int pty_limit; /* Config limit on Unix98 ptys */
@@ -2967,14 +2969,19 @@ static int __init tty_init(void)
#endif
#ifdef CONFIG_VT
- cdev_init(&vc0_cdev, &console_fops);
- if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
- register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
- panic("Couldn't register /dev/tty0 driver\n");
- devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0");
- class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+ if (console_use_vt) {
+ cdev_init(&vc0_cdev, &console_fops);
+ if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
+ register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1,
+ "/dev/vc/0") < 0)
+ panic("Couldn't register /dev/tty0 driver\n");
+ devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR,
+ "vc/0");
+ class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL,
+ "tty0");
- vty_init();
+ vty_init();
+ }
#endif
return 0;
}
_