1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
config VT
bool "Virtual terminal" if EXPERT
depends on !S390
select INPUT
default y
---help---
If you say Y here, you will get support for terminal devices with
display and keyboard devices. These are called "virtual" because you
can run several virtual terminals (also called virtual consoles) on
one physical terminal. This is rather useful, for example one
virtual terminal can collect system messages and warnings, another
one can be used for a text-mode user session, and a third could run
an X session, all in parallel. Switching between virtual terminals
is done with certain key combinations, usually Alt-<function key>.
The setterm command ("man setterm") can be used to change the
properties (such as colors or beeping) of a virtual terminal. The
man page console_codes(4) ("man console_codes") contains the special
character sequences that can be used to change those properties
directly. The fonts used on virtual terminals can be changed with
the setfont ("man setfont") command and the key bindings are defined
with the loadkeys ("man loadkeys") command.
You need at least one virtual terminal device in order to make use
of your keyboard and monitor. Therefore, only people configuring an
embedded system would want to say N here in order to save some
memory; the only way to log into such a system is then via a serial
or network connection.
If unsure, say Y, or else you won't be able to do much with your new
shiny Linux system :-)
config CONSOLE_TRANSLATIONS
depends on VT
default y
bool "Enable character translations in console" if EXPERT
---help---
This enables support for font mapping and Unicode translation
on virtual consoles.
config VT_CONSOLE
bool "Support for console on virtual terminal" if EXPERT
depends on VT
default y
---help---
The system console is the device which receives all kernel messages
and warnings and which allows logins in single user mode. If you
answer Y here, a virtual terminal (the device used to interact with
a physical terminal) can be used as system console. This is the most
common mode of operations, so you should say Y here unless you want
the kernel messages be output only to a serial port (in which case
you should say Y to "Console on serial port", below).
If you do say Y here, by default the currently visible virtual
terminal (/dev/tty0) will be used as system console. You can change
that with a kernel command line option such as "console=tty3" which
would use the third virtual terminal as system console. (Try "man
bootparam" or see the documentation of your boot loader (lilo or
loadlin) about how to pass options to the kernel at boot time.)
If unsure, say Y.
config HW_CONSOLE
bool
depends on VT && !S390 && !UML
default y
config VT_HW_CONSOLE_BINDING
bool "Support for binding and unbinding console drivers"
depends on HW_CONSOLE
default n
---help---
The virtual terminal is the device that interacts with the physical
terminal through console drivers. On these systems, at least one
console driver is loaded. In other configurations, additional console
drivers may be enabled, such as the framebuffer console. If more than
1 console driver is enabled, setting this to 'y' will allow you to
select the console driver that will serve as the backend for the
virtual terminals.
See <file:Documentation/console/console.txt> for more
information. For framebuffer console users, please refer to
<file:Documentation/fb/fbcon.txt>.
config UNIX98_PTYS
bool "Unix98 PTY support" if EXPERT
default y
---help---
A pseudo terminal (PTY) is a software device consisting of two
halves: a master and a slave. The slave device behaves identical to
a physical terminal; the master device is used by a process to
read data from and write data to the slave, thereby emulating a
terminal. Typical programs for the master side are telnet servers
and xterms.
Linux has traditionally used the BSD-like names /dev/ptyxx for
masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
has a number of problems. The GNU C library glibc 2.1 and later,
however, supports the Unix98 naming standard: in order to acquire a
pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
terminal is then made available to the process and the pseudo
terminal slave can be accessed as /dev/pts/<number>. What was
traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
All modern Linux systems use the Unix98 ptys. Say Y unless
you're on an embedded system and want to conserve memory.
config DEVPTS_MULTIPLE_INSTANCES
bool "Support multiple instances of devpts"
depends on UNIX98_PTYS
default n
---help---
Enable support for multiple instances of devpts filesystem.
If you want to have isolated PTY namespaces (eg: in containers),
say Y here. Otherwise, say N. If enabled, each mount of devpts
filesystem with the '-o newinstance' option will create an
independent PTY namespace.
config LEGACY_PTYS
bool "Legacy (BSD) PTY support"
default y
---help---
A pseudo terminal (PTY) is a software device consisting of two
halves: a master and a slave. The slave device behaves identical to
a physical terminal; the master device is used by a process to
read data from and write data to the slave, thereby emulating a
terminal. Typical programs for the master side are telnet servers
and xterms.
Linux has traditionally used the BSD-like names /dev/ptyxx
for masters and /dev/ttyxx for slaves of pseudo
terminals. This scheme has a number of problems, including
security. This option enables these legacy devices; on most
systems, it is safe to say N.
config LEGACY_PTY_COUNT
int "Maximum number of legacy PTY in use"
depends on LEGACY_PTYS
range 0 256
default "256"
---help---
The maximum number of legacy PTYs that can be used at any one time.
The default is 256, and should be more than enough. Embedded
systems may want to reduce this to save memory.
When not in use, each legacy PTY occupies 12 bytes on 32-bit
architectures and 24 bytes on 64-bit architectures.
|
