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Diffstat (limited to 'drivers/tty/Kconfig')
| -rw-r--r-- | drivers/tty/Kconfig | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig new file mode 100644 index 00000000000..9cfbdb318ed --- /dev/null +++ b/drivers/tty/Kconfig @@ -0,0 +1,150 @@ +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. + + |