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/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 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 72config NOCONFIG_CHAN 73 bool 74 default !(XTERM_CHAN && TTY_CHAN && PTY_CHAN && PORT_CHAN && NULL_CHAN) 75 76config 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 86config 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 98config 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 110config 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 132config 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 149config RAW_DRIVER 150 tristate "RAW driver (/dev/raw/rawN) (OBSOLETE)" 151 help 152 The raw driver permits block devices to be bound to /dev/raw/rawN. 153 Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O. 154 See the raw(8) manpage for more details. 155 156 The raw driver is deprecated and will be removed soon. 157 Applications should simply open the device (eg /dev/hda1) 158 with the O_DIRECT flag. 159 160config MAX_RAW_DEVS 161 int "Maximum number of RAW devices to support (1-8192)" 162 depends on RAW_DRIVER 163 default "256" 164 help 165 The maximum number of RAW devices that are supported. 166 Default is 256. Increase this number in case you need lots of 167 raw devices. 168 169config LEGACY_PTY_COUNT 170 int "Maximum number of legacy PTY in use" 171 depends on LEGACY_PTYS 172 default "256" 173 ---help--- 174 The maximum number of legacy PTYs that can be used at any one time. 175 The default is 256, and should be more than enough. Embedded 176 systems may want to reduce this to save memory. 177 178 When not in use, each legacy PTY occupies 12 bytes on 32-bit 179 architectures and 24 bytes on 64-bit architectures. 180 181config WATCHDOG 182 bool "Watchdog Timer Support" 183 184config WATCHDOG_NOWAYOUT 185 bool "Disable watchdog shutdown on close" 186 depends on WATCHDOG 187 188config SOFT_WATCHDOG 189 tristate "Software Watchdog" 190 depends on WATCHDOG 191 192config UML_WATCHDOG 193 tristate "UML watchdog" 194 depends on WATCHDOG 195 196config UML_SOUND 197 tristate "Sound support" 198 help 199 This option enables UML sound support. If enabled, it will pull in 200 soundcore and the UML hostaudio relay, which acts as a intermediary 201 between the host's dsp and mixer devices and the UML sound system. 202 It is safe to say 'Y' here. 203 204config SOUND 205 tristate 206 default UML_SOUND 207 208config HOSTAUDIO 209 tristate 210 default UML_SOUND 211 212#It is selected elsewhere, so kconfig would warn without this. 213config HW_RANDOM 214 tristate 215 default n 216 217config UML_RANDOM 218 tristate "Hardware random number generator" 219 help 220 This option enables UML's "hardware" random number generator. It 221 attaches itself to the host's /dev/random, supplying as much entropy 222 as the host has, rather than the small amount the UML gets from its 223 own drivers. It registers itself as a standard hardware random number 224 generator, major 10, minor 183, and the canonical device name is 225 /dev/hwrng. 226 The way to make use of this is to install the rng-tools package 227 (check your distro, or download from 228 http://sourceforge.net/projects/gkernel/). rngd periodically reads 229 /dev/hwrng and injects the entropy into /dev/random. 230 231config MMAPPER 232 tristate "iomem emulation driver" 233 help 234 This driver allows a host file to be used as emulated IO memory inside 235 UML. 236 237endmenu 238 239