aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/console
diff options
context:
space:
mode:
authorAntonino A. Daplas <adaplas@gmail.com>2006-06-26 03:27:14 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 12:58:33 -0400
commit6690075d0b97837aca533b92715e6357ad6de279 (patch)
treeabd914a173dfc68569fedda51d3b494200b3cbc1 /Documentation/console
parent5bd42536b395944a1134baa3624b2e0cff6ac7bf (diff)
[PATCH] VT binding: Update documentation
Update Documentation/fb/fbcon.txt and Documentatin/console/console.txt to reflect the following changes: 1. sysfs attributes are relocated to /sys/class/vtconsole 2. feature is selectable in Kconfig 3. add sample scripts to fbcon.txt Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'Documentation/console')
-rw-r--r--Documentation/console/console.txt67
1 files changed, 42 insertions, 25 deletions
diff --git a/Documentation/console/console.txt b/Documentation/console/console.txt
index 4f3f28507761..d3e17447321c 100644
--- a/Documentation/console/console.txt
+++ b/Documentation/console/console.txt
@@ -27,45 +27,62 @@ In newer kernels, the following are also available:
27 register_con_driver() 27 register_con_driver()
28 unregister_con_driver() 28 unregister_con_driver()
29 29
30If sysfs is enabled, the contents of /sys/class/tty/console/backend can be 30If sysfs is enabled, the contents of /sys/class/vtconsole can be
31examined. This shows the console drivers currently registered by the system. On 31examined. This shows the console backends currently registered by the
32an x86 system with the framebuffer console enabled, the contents of this 32system which are named vtcon<n> where <n> is an integer fro 0 to 15. Thus:
33attribute may be like this:
34 33
35cat /sys/class/tty/console/backend 34 ls /sys/class/vtconsole
360 S: VGA+ 35 . .. vtcon0 vtcon1
371 B: frame buffer device
38 36
39The first line shows the VGA console driver, while the second line shows 37Each directory in /sys/class/vtconsole has 3 files:
40the framebuffer console driver.
41 38
42The leftmost numeric character is the driver ID. The middle character with 39 ls /sys/class/vtconsole/vtcon0
43the colon describes the status of the driver. 40 . .. bind name uevent
44 41
45 S: - system driver (binding unspecified) 42What do these files signify?
46 B: - bound modular driver
47 U: - unbound modular driver
48 43
49The last column is the description of the driver. 44 1. bind - this is a read/write file. It shows the status of the driver if
45 read, or acts to bind or unbind the driver to the virtual consoles
46 when written to. The possible values are:
50 47
51Under /sys/class/tty/console are two other attributes, 'bind' and 48 0 - means the driver is not bound and if echo'ed, commands the driver
52'unbind'. What does these 2 attributes do? As their name implies, echo'ing the 49 to unbind
53driver ID to 'bind' will bind an unbound modular driver, and to 'unbind' will
54unbind a bound modular driver. Echo'ing the ID of a system driver to either
55attribute will do nothing.
56 50
57Thus: 51 1 - means the driver is bound and if echo'ed, commands the driver to
52 bind
58 53
59echo 1 > /sys/class/tty/console/unbind 54 2. name - read-only file. Shows the name of the driver in this format:
60cat /sys/class/tty/console/backend 55
610 S: VGA+ 56 cat /sys/class/vtconsole/vtcon0/name
621 U: frame buffer device 57 (S) VGA+
58
59 '(S)' stands for a (S)ystem driver, ie, it cannot be directly
60 commanded to bind or unbind
61
62 'VGA+' is the name of the driver
63
64 cat /sys/class/vtconsole/vtcon1/name
65 (M) frame buffer device
66
67 In this case, '(M)' stands for a (M)odular driver, one that can be
68 directly commanded to bind or unbind.
69
70 3. uevent - ignore this file
63 71
64When unbinding, the modular driver is detached first, and then the system 72When unbinding, the modular driver is detached first, and then the system
65driver takes over the consoles vacated by the driver. Binding, on the other 73driver takes over the consoles vacated by the driver. Binding, on the other
66hand, will bind the driver to the consoles that are currently occupied by a 74hand, will bind the driver to the consoles that are currently occupied by a
67system driver. 75system driver.
68 76
77NOTE1: Binding and binding must be selected in Kconfig. It's under:
78
79Device Drivers -> Character devices -> Support for binding and unbinding
80console drivers
81
82NOTE2: If any of the virtual consoles are in KD_GRAPHICS mode, then binding or
83unbinding will not succeed. An example of an application that sets the console
84to KD_GRAPHICS is X.
85
69How useful is this feature? This is very useful for console driver 86How useful is this feature? This is very useful for console driver
70developers. By unbinding the driver from the console layer, one can unload the 87developers. By unbinding the driver from the console layer, one can unload the
71driver, make changes, recompile, reload and rebind the driver without any need 88driver, make changes, recompile, reload and rebind the driver without any need