Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | |
| 2 | menu "Character Devices" |
| 3 | |
| 4 | config STDERR_CONSOLE |
| 5 | bool "stderr console" |
| 6 | default y |
| 7 | help |
| 8 | console driver which dumps all printk messages to stderr. |
| 9 | |
| 10 | config STDIO_CONSOLE |
| 11 | bool |
| 12 | default y |
| 13 | |
| 14 | config SSL |
| 15 | bool "Virtual serial line" |
| 16 | help |
| 17 | The User-Mode Linux environment allows you to create virtual serial |
| 18 | lines on the UML that are usually made to show up on the host as |
| 19 | ttys or ptys. |
| 20 | |
| 21 | See <http://user-mode-linux.sourceforge.net/input.html> for more |
| 22 | information and command line examples of how to use this facility. |
| 23 | |
| 24 | Unless you have a specific reason for disabling this, say Y. |
| 25 | |
| 26 | config NULL_CHAN |
| 27 | bool "null channel support" |
| 28 | help |
| 29 | This option enables support for attaching UML consoles and serial |
| 30 | lines to a device similar to /dev/null. Data written to it disappears |
| 31 | and there is never any data to be read. |
| 32 | |
| 33 | config PORT_CHAN |
| 34 | bool "port channel support" |
| 35 | help |
| 36 | This option enables support for attaching UML consoles and serial |
| 37 | lines to host portals. They may be accessed with 'telnet <host> |
| 38 | <port number>'. Any number of consoles and serial lines may be |
| 39 | attached to a single portal, although what UML device you get when |
| 40 | you telnet to that portal will be unpredictable. |
| 41 | It is safe to say 'Y' here. |
| 42 | |
| 43 | config PTY_CHAN |
| 44 | bool "pty channel support" |
| 45 | help |
| 46 | This option enables support for attaching UML consoles and serial |
| 47 | lines to host pseudo-terminals. Access to both traditional |
| 48 | pseudo-terminals (/dev/pty*) and pts pseudo-terminals are controlled |
| 49 | with this option. The assignment of UML devices to host devices |
| 50 | will be announced in the kernel message log. |
| 51 | It is safe to say 'Y' here. |
| 52 | |
| 53 | config TTY_CHAN |
| 54 | bool "tty channel support" |
| 55 | help |
| 56 | This option enables support for attaching UML consoles and serial |
| 57 | lines to host terminals. Access to both virtual consoles |
| 58 | (/dev/tty*) and the slave side of pseudo-terminals (/dev/ttyp* and |
| 59 | /dev/pts/*) are controlled by this option. |
| 60 | It is safe to say 'Y' here. |
| 61 | |
| 62 | config XTERM_CHAN |
| 63 | bool "xterm channel support" |
| 64 | help |
| 65 | This option enables support for attaching UML consoles and serial |
| 66 | lines to xterms. Each UML device so assigned will be brought up in |
| 67 | its own xterm. |
| 68 | If you disable this option, then CONFIG_PT_PROXY will be disabled as |
| 69 | well, since UML's gdb currently requires an xterm. |
| 70 | It is safe to say 'Y' here. |
| 71 | |
| 72 | config NOCONFIG_CHAN |
| 73 | bool |
| 74 | default !(XTERM_CHAN && TTY_CHAN && PTY_CHAN && PORT_CHAN && NULL_CHAN) |
| 75 | |
| 76 | config CON_ZERO_CHAN |
| 77 | string "Default main console channel initialization" |
| 78 | default "fd:0,fd:1" |
| 79 | help |
| 80 | This is the string describing the channel to which the main console |
| 81 | will be attached by default. This value can be overridden from the |
| 82 | command line. The default value is "fd:0,fd:1", which attaches the |
| 83 | main console to stdin and stdout. |
| 84 | It is safe to leave this unchanged. |
| 85 | |
| 86 | config CON_CHAN |
| 87 | string "Default console channel initialization" |
| 88 | default "xterm" |
| 89 | help |
| 90 | This is the string describing the channel to which all consoles |
| 91 | except the main console will be attached by default. This value can |
| 92 | be overridden from the command line. The default value is "xterm", |
| 93 | which brings them up in xterms. |
| 94 | It is safe to leave this unchanged, although you may wish to change |
| 95 | this if you expect the UML that you build to be run in environments |
| 96 | which don't have X or xterm available. |
| 97 | |
| 98 | config SSL_CHAN |
| 99 | string "Default serial line channel initialization" |
| 100 | default "pty" |
| 101 | help |
| 102 | This is the string describing the channel to which the serial lines |
| 103 | will be attached by default. This value can be overridden from the |
| 104 | command line. The default value is "pty", which attaches them to |
| 105 | traditional pseudo-terminals. |
| 106 | It is safe to leave this unchanged, although you may wish to change |
| 107 | this if you expect the UML that you build to be run in environments |
| 108 | which don't have a set of /dev/pty* devices. |
| 109 | |
| 110 | config UNIX98_PTYS |
| 111 | bool "Unix98 PTY support" |
| 112 | ---help--- |
| 113 | A pseudo terminal (PTY) is a software device consisting of two |
| 114 | halves: a master and a slave. The slave device behaves identical to |
| 115 | a physical terminal; the master device is used by a process to |
| 116 | read data from and write data to the slave, thereby emulating a |
| 117 | terminal. Typical programs for the master side are telnet servers |
| 118 | and xterms. |
| 119 | |
| 120 | Linux has traditionally used the BSD-like names /dev/ptyxx for |
| 121 | masters and /dev/ttyxx for slaves of pseudo terminals. This scheme |
| 122 | has a number of problems. The GNU C library glibc 2.1 and later, |
| 123 | however, supports the Unix98 naming standard: in order to acquire a |
| 124 | pseudo terminal, a process opens /dev/ptmx; the number of the pseudo |
| 125 | terminal is then made available to the process and the pseudo |
| 126 | terminal slave can be accessed as /dev/pts/<number>. What was |
| 127 | traditionally /dev/ttyp2 will then be /dev/pts/2, for example. |
| 128 | |
| 129 | All modern Linux systems use the Unix98 ptys. Say Y unless |
| 130 | you're on an embedded system and want to conserve memory. |
| 131 | |
| 132 | config LEGACY_PTYS |
| 133 | bool "Legacy (BSD) PTY support" |
| 134 | default y |
| 135 | ---help--- |
| 136 | A pseudo terminal (PTY) is a software device consisting of two |
| 137 | halves: a master and a slave. The slave device behaves identical to |
| 138 | a physical terminal; the master device is used by a process to |
| 139 | read data from and write data to the slave, thereby emulating a |
| 140 | terminal. Typical programs for the master side are telnet servers |
| 141 | and xterms. |
| 142 | |
| 143 | Linux has traditionally used the BSD-like names /dev/ptyxx |
| 144 | for masters and /dev/ttyxx for slaves of pseudo |
| 145 | terminals. This scheme has a number of problems, including |
| 146 | security. This option enables these legacy devices; on most |
| 147 | systems, it is safe to say N. |
| 148 | |
| 149 | |
| 150 | config LEGACY_PTY_COUNT |
| 151 | int "Maximum number of legacy PTY in use" |
| 152 | depends on LEGACY_PTYS |
| 153 | default "256" |
| 154 | ---help--- |
| 155 | The maximum number of legacy PTYs that can be used at any one time. |
| 156 | The default is 256, and should be more than enough. Embedded |
| 157 | systems may want to reduce this to save memory. |
| 158 | |
| 159 | When not in use, each legacy PTY occupies 12 bytes on 32-bit |
| 160 | architectures and 24 bytes on 64-bit architectures. |
| 161 | |
| 162 | config WATCHDOG |
| 163 | bool "Watchdog Timer Support" |
| 164 | |
| 165 | config WATCHDOG_NOWAYOUT |
| 166 | bool "Disable watchdog shutdown on close" |
| 167 | depends on WATCHDOG |
| 168 | |
| 169 | config SOFT_WATCHDOG |
| 170 | tristate "Software Watchdog" |
| 171 | depends on WATCHDOG |
| 172 | |
| 173 | config UML_WATCHDOG |
| 174 | tristate "UML watchdog" |
| 175 | depends on WATCHDOG |
| 176 | |
| 177 | config UML_SOUND |
| 178 | tristate "Sound support" |
| 179 | help |
| 180 | This option enables UML sound support. If enabled, it will pull in |
| 181 | soundcore and the UML hostaudio relay, which acts as a intermediary |
| 182 | between the host's dsp and mixer devices and the UML sound system. |
| 183 | It is safe to say 'Y' here. |
| 184 | |
| 185 | config SOUND |
| 186 | tristate |
| 187 | default UML_SOUND |
| 188 | |
| 189 | config HOSTAUDIO |
| 190 | tristate |
| 191 | default UML_SOUND |
| 192 | |
| 193 | config UML_RANDOM |
| 194 | tristate "Hardware random number generator" |
| 195 | help |
| 196 | This option enables UML's "hardware" random number generator. It |
| 197 | attaches itself to the host's /dev/random, supplying as much entropy |
| 198 | as the host has, rather than the small amount the UML gets from its |
| 199 | own drivers. It registers itself as a standard hardware random number |
| 200 | generator, major 10, minor 183, and the canonical device name is |
| 201 | /dev/hwrng. |
| 202 | The way to make use of this is to install the rng-tools package |
| 203 | (check your distro, or download from |
| 204 | http://sourceforge.net/projects/gkernel/). rngd periodically reads |
| 205 | /dev/hwrng and injects the entropy into /dev/random. |
| 206 | |
| 207 | endmenu |
| 208 | |