help.common revision 148398
1################################################################################ 2# Thelp DDisplay command help 3 4 help [topic [subtopic]] 5 help index 6 7 The help command displays help on commands and their usage. 8 9 In command help, a term enclosed with <...> indicates a value as 10 described by the term. A term enclosed with [...] is optional, 11 and may not be required by all forms of the command. 12 13 Some commands may not be available. Use the '?' command to list 14 most available commands. 15 16################################################################################ 17# T? DList available commands 18 19 ? 20 21 Lists all available commands. 22 23################################################################################ 24# Tautoboot DBoot after a delay 25 26 autoboot [<delay> [<prompt>]] 27 28 Displays <prompt> or a default prompt, and counts down <delay> seconds 29 before attempting to boot. If <delay> is not specified, the default 30 value is 10. 31 32################################################################################ 33# Tboot DBoot immediately 34 35 boot [<kernelname>] [-<arg> ...] 36 37 Boot the system. If arguments are specified, they are added to the 38 arguments for the kernel. If <kernelname> is specified, and a kernel 39 has not already been loaded, it will be booted instead of the default 40 kernel. 41 42################################################################################ 43# Tbcachestat DGet disk block cache stats 44 45 bcachestat 46 47 Displays statistics about disk cache usage. For depuration only. 48 49################################################################################ 50# Techo DEcho arguments 51 52 echo [-n] [<message>] 53 54 Emits <message>, with no trailing newline if -n is specified. This is 55 most useful in conjunction with scripts and the '@' line prefix. 56 57 Variables are substituted by prefixing them with $, eg. 58 59 echo Current device is $currdev 60 61 will print the current device. 62 63################################################################################ 64# Tload DLoad a kernel or module 65 66 load [-t <type>] <filename> 67 68 Loads the module contained in <filename> into memory. If no other 69 modules are loaded, <filename> must be a kernel or the command will 70 fail. 71 72 If -t is specified, the module is loaded as raw data of <type>, for 73 later use by the kernel or other modules. <type> may be any string. 74 75################################################################################ 76# Tls DList files 77 78 ls [-l] [<path>] 79 80 Displays a listing of files in the directory <path>, or the root 81 directory of the current device if <path> is not specified. 82 83 The -l argument displays file sizes as well; the process of obtaining 84 file sizes on some media may be very slow. 85 86################################################################################ 87# Tlsdev DList devices 88 89 lsdev [-v] 90 91 List all of the devices from which it may be possible to load modules. 92 If -v is specified, print more details. 93 94################################################################################ 95# Tlsmod DList modules 96 97 lsmod [-v] 98 99 List loaded modules. If [-v] is specified, print more details. 100 101################################################################################ 102# Tmore DPage files 103 104 more <filename> [<filename> ...] 105 106 Show contents of text files. When displaying the contents of more, 107 than one file, if the user elects to quit displaying a file, the 108 remaining files will not be shown. 109 110################################################################################ 111# Tpnpscan DScan for PnP devices 112 113 pnpscan [-v] 114 115 Scan for Plug-and-Play devices. This command is normally automatically 116 run as part of the boot process, in order to dynamically load modules 117 required for system operation. 118 119 If the -v argument is specified, details on the devices found will 120 be printed. 121 122################################################################################ 123# Tset DSet a variable 124 125 set <variable name> 126 set <variable name>=<value> 127 128 The set command is used to set variables. 129 130################################################################################ 131# Tset Sautoboot_delay DSet the default autoboot delay 132 133 set autoboot_delay=<value> 134 135 Sets the default delay for the autoboot command to <value> seconds. 136 Set value to -1 if you don't want to allow user to interrupt autoboot 137 process and escape to the loader prompt. 138 139################################################################################ 140# Tset Sbootfile DSet the default boot file set 141 142 set bootfile=<filename>[;<filename>...] 143 144 Sets the default set of kernel boot filename(s). It may be overridden 145 by setting the bootfile variable to a semicolon-separated list of 146 filenames, each of which will be searched for in the module_path 147 directories. The default bootfile set is "kernel". 148 149################################################################################ 150# Tset Sboot_askname DPrompt for root device 151 152 set boot_askname 153 154 Instructs the kernel to prompt the user for the name of the root device 155 when the kernel is booted. 156 157################################################################################ 158# Tset Sboot_cdrom DMount root file system from CD-ROM 159 160 set boot_cdrom 161 162 Instructs the kernel to try to mount the root file system from CD-ROM. 163 164################################################################################ 165# Tset Sboot_ddb DDrop to the kernel debugger (DDB) 166 167 set boot_ddb 168 169 Instructs the kernel to start in the DDB debugger, rather than 170 proceeding to initialize when booted. 171 172################################################################################ 173# Tset Sboot_gdb DSelect gdb-remote mode for the kernel debugger 174 175 set boot_gdb 176 177 Selects gdb-remote mode for the kernel debugger by default. 178 179################################################################################ 180# Tset Sboot_multicons DUse multiple consoles 181 182 set boot_multicons 183 184 Enables multiple console support in the kernel early on boot. 185 In a running system, console configuration can be manipulated 186 by the conscontrol(8) utility. 187 188################################################################################ 189# Tset Sboot_serial DUse serial console 190 191 set boot_serial 192 193 Force the use of a serial console even when an internal console 194 is present. 195 196################################################################################ 197# Tset Sboot_single DStart system in single-user mode 198 199 set boot_single 200 201 Prevents the kernel from initiating a multi-user startup; instead, 202 a single-user mode will be entered when the kernel has finished 203 device probes. 204 205################################################################################ 206# Tset Sboot_verbose DVerbose boot messages 207 208 set boot_verbose 209 210 Setting this variable causes extra debugging information to be printed 211 by the kernel during the boot phase. 212 213################################################################################ 214# Tset Sconsole DSet the current console 215 216 set console[=<value>] 217 218 Sets the current console. If <value> is omitted, a list of valid 219 consoles will be displayed. 220 221################################################################################ 222# Tset Scurrdev DSet the current device 223 224 set currdev=<device> 225 226 Selects the default device. See lsdev for available devices. 227 228################################################################################ 229# Tset Sinit_path DSet the list of init candidates 230 231 set init_path=<path>[:<path>...] 232 233 Sets the list of binaries which the kernel will try to run as initial 234 process. 235 236 237################################################################################ 238# Tset Smodule_path DSet the module search path 239 240 set module_path=<path>[;<path>...] 241 242 Sets the list of directories which will be searched in for modules 243 named in a load command or implicitly required by a dependency. The 244 default module_path is "/boot/modules" with the kernel directory 245 prepended. 246 247################################################################################ 248# Tset Sprompt DSet the command prompt 249 250 set prompt=<value> 251 252 The command prompt is displayed when the loader is waiting for input. 253 Variable substitution is performed on the prompt. The default 254 prompt can be set with: 255 256 set prompt=\${interpret} 257 258################################################################################ 259# Tset Srootdev DSet the root filesystem 260 261 set rootdev=<path> 262 263 By default the value of $currdev is used to set the root filesystem 264 when the kernel is booted. This can be overridden by setting 265 $rootdev explicitly. 266 267################################################################################ 268# Tset Stunables DSet kernel tunable values 269 270 Various kernel tunable parameters can be overridden by specifying new 271 values in the environment. 272 273 set kern.ipc.nmbclusters=<value> NMBCLUSTERS 274 275 Set the number of mbuf clusters to be allocated. The value 276 cannot be set below the default determined when the kernel 277 was compiled. 278 279 set kern.ipc.nsfbufs=<value> NSFBUFS 280 281 Set the number of sendfile buffers to be allocated. This 282 overrides the value determined when the kernel was compiled. 283 284 set vm.kmem_size=<value> VM_KMEM_SIZE 285 286 Sets the size of kernel memory (bytes). This overrides 287 the value determined when the kernel was compiled. 288 289 set machdep.disable_mtrrs=1 290 291 Disable the use of i686 MTRRs (i386 only) 292 293 set net.inet.tcp.tcbhashsize=<value> TCBHASHSIZE 294 295 Overrides the compile-time set value of TCBHASHSIZE or 296 the preset default of 512. Must be a power of 2. 297 298 hw.syscons.sc_no_suspend_vtswitch=<value> 299 300 Disable VT switching on suspend. 301 302 value is 0 (default) or non-zero to enable. 303 304 set hw.physmem=<value> MAXMEM (i386 only) 305 306 Limits the amount of physical memory space available to 307 the system to <value> bytes. <value> may have a k, M or G 308 suffix to indicate kilobytes, megabytes and gigabytes 309 respectively. Note that the current i386 architecture 310 limits this value to 4GB. 311 312 On systems where memory cannot be accurately probed, 313 this option provides a hint as to the actual size of 314 system memory (which will be tested before use). 315 316 set hw.{acpi,pci}.host_start_mem=<value> 317 318 Sets the lowest address that the pci code will assign 319 when it doesn't have other information about the address 320 to assign (like from a pci bridge). This is only useful 321 in older systems without a pci bridge. Also, it only 322 impacts devices that the BIOS doesn't assign to, typically 323 CardBus bridges. The default <value> is 0x80000000, but 324 some systems need values like 0xf0000000, 0xfc000000 or 325 0xfe000000 may be suitable for older systems (the older 326 the system, the higher the number typically should be). 327 328 set hw.pci.enable_io_modes=<value> 329 330 Enable PCI resources which are left off by some BIOSes 331 or are not enabled correctly by the device driver. 332 333 value is 1 (default), but this may cause problems with 334 some peripherals. Set to 0 to disable. 335 336################################################################################ 337# Tshow DShow the values of variables 338 339 show [<variable>] 340 341 Displays the value of <variable>, or all variables if not specified. 342 Multiple paths can be separated with a semicolon. 343 344################################################################################ 345# Tinclude DRead commands from a script file 346 347 include <filename> [<filename> ...] 348 349 The entire contents of <filename> are read into memory before executing 350 commands, so it is safe to source a file from removable media. 351 352################################################################################ 353# Tread DRead input from the terminal 354 355 read [-t <value>] [-p <prompt>] [<variable name>] 356 357 The read command reads a line of input from the terminal. If the 358 -t argument is specified, it will return nothing if no input has been 359 received after <value> seconds. (Any keypress will cancel the 360 timeout). 361 362 If -p is specified, <prompt> is printed before reading input. No 363 newline is emitted after the prompt. 364 365 If a variable name is supplied, the variable is set to the value read, 366 less any terminating newline. 367 368################################################################################ 369# Tunload DRemove all modules from memory 370 371 unload 372 373 This command removes any kernel and all loaded modules from memory. 374 375################################################################################ 376# Tunset DUnset a variable 377 378 unset <variable name> 379 380 If allowed, the named variable's value is discarded and the variable 381 is removed. 382 383################################################################################ 384