1 2menu "Character Devices" 3 4config STDERR_CONSOLE 5 bool "stderr console" 6 default y 7 help 8 console driver which dumps all printk messages to stderr. 9 10config STDIO_CONSOLE 11 bool 12 default y 13 14config 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/old/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 26config 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 33config 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 43config 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 53config 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 62config 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 It is safe to say 'Y' here. 69 70config NOCONFIG_CHAN 71 bool 72 default !(XTERM_CHAN && TTY_CHAN && PTY_CHAN && PORT_CHAN && NULL_CHAN) 73 74config CON_ZERO_CHAN 75 string "Default main console channel initialization" 76 default "fd:0,fd:1" 77 help 78 This is the string describing the channel to which the main console 79 will be attached by default. This value can be overridden from the 80 command line. The default value is "fd:0,fd:1", which attaches the 81 main console to stdin and stdout. 82 It is safe to leave this unchanged. 83 84config CON_CHAN 85 string "Default console channel initialization" 86 default "xterm" 87 help 88 This is the string describing the channel to which all consoles 89 except the main console will be attached by default. This value can 90 be overridden from the command line. The default value is "xterm", 91 which brings them up in xterms. 92 It is safe to leave this unchanged, although you may wish to change 93 this if you expect the UML that you build to be run in environments 94 which don't have X or xterm available. 95 96config SSL_CHAN 97 string "Default serial line channel initialization" 98 default "pty" 99 help 100 This is the string describing the channel to which the serial lines 101 will be attached by default. This value can be overridden from the 102 command line. The default value is "pty", which attaches them to 103 traditional pseudo-terminals. 104 It is safe to leave this unchanged, although you may wish to change 105 this if you expect the UML that you build to be run in environments 106 which don't have a set of /dev/pty* devices. 107 108config UNIX98_PTYS 109 bool "Unix98 PTY support" 110 help 111 A pseudo terminal (PTY) is a software device consisting of two 112 halves: a master and a slave. The slave device behaves identical to 113 a physical terminal; the master device is used by a process to 114 read data from and write data to the slave, thereby emulating a 115 terminal. Typical programs for the master side are telnet servers 116 and xterms. 117 118 Linux has traditionally used the BSD-like names /dev/ptyxx for 119 masters and /dev/ttyxx for slaves of pseudo terminals. This scheme 120 has a number of problems. The GNU C library glibc 2.1 and later, 121 however, supports the Unix98 naming standard: in order to acquire a 122 pseudo terminal, a process opens /dev/ptmx; the number of the pseudo 123 terminal is then made available to the process and the pseudo 124 terminal slave can be accessed as /dev/pts/<number>. What was 125 traditionally /dev/ttyp2 will then be /dev/pts/2, for example. 126 127 All modern Linux systems use the Unix98 ptys. Say Y unless 128 you're on an embedded system and want to conserve memory. 129 130config LEGACY_PTYS 131 bool "Legacy (BSD) PTY support" 132 default y 133 help 134 A pseudo terminal (PTY) is a software device consisting of two 135 halves: a master and a slave. The slave device behaves identical to 136 a physical terminal; the master device is used by a process to 137 read data from and write data to the slave, thereby emulating a 138 terminal. Typical programs for the master side are telnet servers 139 and xterms. 140 141 Linux has traditionally used the BSD-like names /dev/ptyxx 142 for masters and /dev/ttyxx for slaves of pseudo 143 terminals. This scheme has a number of problems, including 144 security. This option enables these legacy devices; on most 145 systems, it is safe to say N. 146 147config RAW_DRIVER 148 tristate "RAW driver (/dev/raw/rawN)" 149 depends on BLOCK 150 help 151 The raw driver permits block devices to be bound to /dev/raw/rawN. 152 Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O. 153 See the raw(8) manpage for more details. 154 155 Applications should preferably open the device (eg /dev/hda1) 156 with the O_DIRECT flag. 157 158config MAX_RAW_DEVS 159 int "Maximum number of RAW devices to support (1-8192)" 160 depends on RAW_DRIVER 161 default "256" 162 help 163 The maximum number of RAW devices that are supported. 164 Default is 256. Increase this number in case you need lots of 165 raw devices. 166 167config LEGACY_PTY_COUNT 168 int "Maximum number of legacy PTY in use" 169 depends on LEGACY_PTYS 170 default "256" 171 help 172 The maximum number of legacy PTYs that can be used at any one time. 173 The default is 256, and should be more than enough. Embedded 174 systems may want to reduce this to save memory. 175 176 When not in use, each legacy PTY occupies 12 bytes on 32-bit 177 architectures and 24 bytes on 64-bit architectures. 178 179config WATCHDOG 180 bool "Watchdog Timer Support" 181 182config WATCHDOG_NOWAYOUT 183 bool "Disable watchdog shutdown on close" 184 depends on WATCHDOG 185 186config SOFT_WATCHDOG 187 tristate "Software Watchdog" 188 depends on WATCHDOG 189 190config UML_WATCHDOG 191 tristate "UML watchdog" 192 depends on WATCHDOG 193 194config UML_SOUND 195 tristate "Sound support" 196 help 197 This option enables UML sound support. If enabled, it will pull in 198 soundcore and the UML hostaudio relay, which acts as a intermediary 199 between the host's dsp and mixer devices and the UML sound system. 200 It is safe to say 'Y' here. 201 202config SOUND 203 tristate 204 default UML_SOUND 205 206config SOUND_OSS_CORE 207 bool 208 default UML_SOUND 209 210config HOSTAUDIO 211 tristate 212 default UML_SOUND 213 214#It is selected elsewhere, so kconfig would warn without this. 215config HW_RANDOM 216 tristate 217 default n 218 219config UML_RANDOM 220 tristate "Hardware random number generator" 221 help 222 This option enables UML's "hardware" random number generator. It 223 attaches itself to the host's /dev/random, supplying as much entropy 224 as the host has, rather than the small amount the UML gets from its 225 own drivers. It registers itself as a standard hardware random number 226 generator, major 10, minor 183, and the canonical device name is 227 /dev/hwrng. 228 The way to make use of this is to install the rng-tools package 229 (check your distro, or download from 230 http://sourceforge.net/projects/gkernel/). rngd periodically reads 231 /dev/hwrng and injects the entropy into /dev/random. 232 233config MMAPPER 234 tristate "iomem emulation driver" 235 help 236 This driver allows a host file to be used as emulated IO memory inside 237 UML. 238 239endmenu 240