menu "Character Devices"
config STDERR_CONSOLE
bool "stderr console"
default y
help
console driver which dumps all printk messages to stderr.
config STDIO_CONSOLE
bool
default y
config SSL
bool "Virtual serial line"
help
The User-Mode Linux environment allows you to create virtual serial
lines on the UML that are usually made to show up on the host as
ttys or ptys.
See <http://user-mode-linux.sourceforge.net/input.html> for more
information and command line examples of how to use this facility.
Unless you have a specific reason for disabling this, say Y.
config NULL_CHAN
bool "null channel support"
help
This option enables support for attaching UML consoles and serial
lines to a device similar to /dev/null. Data written to it disappears
and there is never any data to be read.
config PORT_CHAN
bool "port channel support"
help
This option enables support for attaching UML consoles and serial
lines to host portals. They may be accessed with 'telnet <host>
<port number>'. Any number of consoles and serial lines may be
attached to a single portal, although what UML device you get when
you telnet to that portal will be unpredictable.
It is safe to say 'Y' here.
config PTY_CHAN
bool "pty channel support"
help
This option enables support for attaching UML consoles and serial
lines to host pseudo-terminals. Access to both traditional
pseudo-terminals (/dev/pty*) and pts pseudo-terminals are controlled
with this option. The assignment of UML devices to host devices
will be announced in the kernel message log.
It is safe to say 'Y' here.
config TTY_CHAN
bool "tty channel support"
help
This option enables support for attaching UML consoles and serial
lines to host terminals. Access to both virtual consoles
(/dev/tty*) and the slave side of pseudo-terminals (/dev/ttyp* and
/dev/pts/*) are controlled by this option.
It is safe to say 'Y' here.
config XTERM_CHAN
bool "xterm channel support"
help
This option enables support for attaching UML consoles and serial
lines to xterms. Each UML device so assigned will be brought up in
its own xterm.
If you disable this option, then CONFIG_PT_PROXY will be disabled as
well, since UML's gdb currently requires an xterm.
It is safe to say 'Y' here.
config NOCONFIG_CHAN
bool
default !(XTERM_CHAN && TTY_CHAN && PTY_CHAN && PORT_CHAN && NULL_CHAN)
config CON_ZERO_CHAN
string "Default main console channel initialization"
default "fd:0,fd:1"
help
This is the string describing the channel to which the main console
will be attached by default. This value can be overridden from the
command line. The default value is "fd:0,fd:1", which attaches the
main console to stdin and stdout.
It is safe to leave this unchanged.
config CON_CHAN
string "Default console channel initialization"
default "xterm"
help
This is the string describing the channel to which all consoles
except the main console will be attached by default. This value can
be overridden from the command line. The default value is "xterm",
which brings them up in xterms.
It is safe to leave this unchanged, although you may wish to change
this if you expect the UML that you build to be run in environments
which don't have X or xterm available.
config SSL_CHAN
string "Default serial line channel initialization"
default "pty"
help
This is the string describing the channel to which the serial lines
will be attached by default. This value can be overridden from the
command line. The default value is "pty", which attaches them to
traditional pseudo-terminals.
It is safe to leave this unchanged, although you may wish to change
this if you expect the UML that you build to be run in environments
which don't have a set of /dev/pty* devices.
config UNIX98_PTYS
bool "Unix98 PTY support"
---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 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
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.
config WATCHDOG
bool "Watchdog Timer Support"
config WATCHDOG_NOWAYOUT
bool "Disable watchdog shutdown on close"
depends on WATCHDOG
config SOFT_WATCHDOG
tristate "Software Watchdog"
depends on WATCHDOG
config UML_WATCHDOG
tristate "UML watchdog"
depends on WATCHDOG
config UML_SOUND
tristate "Sound support"
help
This option enables UML sound support. If enabled, it will pull in
soundcore and the UML hostaudio relay, which acts as a intermediary
between the host's dsp and mixer devices and the UML sound system.
It is safe to say 'Y' here.
config SOUND
tristate
default UML_SOUND
config HOSTAUDIO
tristate
default UML_SOUND
config UML_RANDOM
tristate "Hardware random number generator"
help
This option enables UML's "hardware" random number generator. It
attaches itself to the host's /dev/random, supplying as much entropy
as the host has, rather than the small amount the UML gets from its
own drivers. It registers itself as a standard hardware random number
generator, major 10, minor 183, and the canonical device name is
/dev/hwrng.
The way to make use of this is to install the rng-tools package
(check your distro, or download from
http://sourceforge.net/projects/gkernel/). rngd periodically reads
/dev/hwrng and injects the entropy into /dev/random.
endmenu
