1 ################################################################################
2 # Thelp DDisplay command help
4 help [topic [subtopic]]
7 The help command displays help on commands and their usage.
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.
13 Some commands may not be available. Use the '?' command to list
14 most available commands.
16 ################################################################################
17 # T? DList available commands
21 Lists all available commands.
23 ################################################################################
24 # Tautoboot DBoot after a delay
26 autoboot [<delay> [<prompt>]]
28 Displays <prompt> or a default prompt, and counts down <delay> seconds
29 before attempting to boot. If <delay> is not specified, the default
32 ################################################################################
33 # Tboot DBoot immediately
35 boot [<kernelname>] [-<arg> ...]
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
42 ################################################################################
43 # Tbcachestat DGet disk block cache stats
47 Displays statistics about disk cache usage. For debugging only.
49 ################################################################################
50 # Techo DEcho arguments
54 Emits <message>, with no trailing newline if -n is specified. This is
55 most useful in conjunction with scripts and the '@' line prefix.
57 Variables are substituted by prefixing them with $, eg.
59 echo Current device is $currdev
61 will print the current device.
63 ################################################################################
64 # Tload DLoad a kernel or module
66 load [-t <type>] <filename>
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
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.
75 ################################################################################
80 Displays a listing of files in the directory <path>, or the root
81 directory of the current device if <path> is not specified.
83 The -l argument displays file sizes as well; the process of obtaining
84 file sizes on some media may be very slow.
86 ################################################################################
87 # Tlsdev DList devices
91 List all of the devices from which it may be possible to load modules.
92 If -v is specified, print more details.
94 ################################################################################
95 # Tlsmod DList modules
99 List loaded modules. If [-v] is specified, print more details.
101 ################################################################################
102 # Tmap-vdisk DMap virtual disk
106 Map file as virtual disk.
108 ################################################################################
111 more <filename> [<filename> ...]
113 Show contents of text files. When displaying the contents of more,
114 than one file, if the user elects to quit displaying a file, the
115 remaining files will not be shown.
117 ################################################################################
118 # Tpnpscan DScan for PnP devices
122 Scan for Plug-and-Play devices. This command is normally automatically
123 run as part of the boot process, in order to dynamically load modules
124 required for system operation.
126 If the -v argument is specified, details on the devices found will
129 ################################################################################
130 # Tset DSet a variable
133 set <variable name>=<value>
135 The set command is used to set variables.
137 ################################################################################
138 # Tset Sautoboot_delay DSet the default autoboot delay
140 set autoboot_delay=<value>
142 Sets the default delay for the autoboot command to <value> seconds.
143 Set value to -1 if you don't want to allow user to interrupt autoboot
144 process and escape to the loader prompt.
146 ################################################################################
147 # Tset Sbootfile DSet the default boot file set
149 set bootfile=<filename>[;<filename>...]
151 Sets the default set of kernel boot filename(s). It may be overridden
152 by setting the bootfile variable to a semicolon-separated list of
153 filenames, each of which will be searched for in the module_path
154 directories. The default bootfile set is "kernel".
156 ################################################################################
157 # Tset Sboot_askname DPrompt for root device
161 Instructs the kernel to prompt the user for the name of the root device
162 when the kernel is booted.
164 ################################################################################
165 # Tset Sboot_cdrom DMount root file system from CD-ROM
169 Instructs the kernel to try to mount the root file system from CD-ROM.
171 ################################################################################
172 # Tset Sboot_ddb DDrop to the kernel debugger (DDB)
176 Instructs the kernel to start in the DDB debugger, rather than
177 proceeding to initialize when booted.
179 ################################################################################
180 # Tset Sboot_dfltroot DUse default root file system
184 Instructs the kernel to mount the statically compiled-in root
187 ################################################################################
188 # Tset Sboot_gdb DSelect gdb-remote mode for the kernel debugger
192 Selects gdb-remote mode for the kernel debugger by default.
194 ################################################################################
195 # Tset Sboot_multicons DUse multiple consoles
199 Enables multiple console support in the kernel early on boot.
200 In a running system, console configuration can be manipulated
201 by the conscontrol(8) utility.
203 ################################################################################
204 # Tset Sboot_mute DMute the console
208 All console output is suppressed when console is muted.
209 In a running system, the state of console muting can be
210 manipulated by the conscontrol(8) utility.
212 ################################################################################
213 # Tset Sboot_pause DPause after each line during device probing
217 During the device probe, pause after each line is printed.
219 ################################################################################
220 # Tset Sboot_serial DUse serial console
224 Force the use of a serial console even when an internal console
227 ################################################################################
228 # Tset Sboot_single DStart system in single-user mode
232 Prevents the kernel from initiating a multi-user startup; instead,
233 a single-user mode will be entered when the kernel has finished
236 ################################################################################
237 # Tset Sboot_verbose DVerbose boot messages
241 Setting this variable causes extra debugging information to be printed
242 by the kernel during the boot phase.
244 ################################################################################
245 # Tset Sconsole DSet the current console
247 set console[=<value>]
249 Sets the current console. If <value> is omitted, a list of valid
250 consoles will be displayed.
252 ################################################################################
253 # Tset Scurrdev DSet the current device
257 Selects the default device. See lsdev for available devices.
259 ################################################################################
260 # Tset Sinit_path DSet the list of init candidates
262 set init_path=<path>[:<path>...]
264 Sets the list of binaries which the kernel will try to run as initial
268 ################################################################################
269 # Tset Smodule_path DSet the module search path
271 set module_path=<path>[;<path>...]
273 Sets the list of directories which will be searched in for modules
274 named in a load command or implicitly required by a dependency. The
275 default module_path is "/boot/modules" with the kernel directory
278 ################################################################################
279 # Tset Sprompt DSet the command prompt
283 The command prompt is displayed when the loader is waiting for input.
284 Variable substitution is performed on the prompt. The default
285 prompt can be set with:
287 set prompt=\${interpret}
289 ################################################################################
290 # Tset Srootdev DSet the root filesystem
294 By default the value of $currdev is used to set the root filesystem
295 when the kernel is booted. This can be overridden by setting
298 ################################################################################
299 # Tset Stunables DSet kernel tunable values
301 Various kernel tunable parameters can be overridden by specifying new
302 values in the environment.
304 set kern.ipc.nmbclusters=<value>
306 Set the number of mbuf clusters to be allocated. The value
307 cannot be set below the default determined when the kernel
310 set kern.ipc.nsfbufs=<value> NSFBUFS
312 Set the number of sendfile buffers to be allocated. This
313 overrides the value determined when the kernel was compiled.
315 set vm.kmem_size=<value> VM_KMEM_SIZE
317 Sets the size of kernel memory (bytes). This overrides
318 the value determined when the kernel was compiled.
320 set machdep.disable_mtrrs=1
322 Disable the use of i686 MTRRs (i386 only)
324 set net.inet.tcp.tcbhashsize=<value> TCBHASHSIZE
326 Overrides the compile-time set value of TCBHASHSIZE or
327 the preset default of 512. Must be a power of 2.
329 hw.syscons.sc_no_suspend_vtswitch=<value>
331 Disable VT switching on suspend.
333 value is 0 (default) or non-zero to enable.
335 set hw.physmem=<value> MAXMEM (i386 only)
337 Limits the amount of physical memory space available to
338 the system to <value> bytes. <value> may have a k, M or G
339 suffix to indicate kilobytes, megabytes and gigabytes
340 respectively. Note that the current i386 architecture
341 limits this value to 4GB.
343 On systems where memory cannot be accurately probed,
344 this option provides a hint as to the actual size of
345 system memory (which will be tested before use).
347 set hw.{acpi,pci}.host_start_mem=<value>
349 Sets the lowest address that the pci code will assign
350 when it doesn't have other information about the address
351 to assign (like from a pci bridge). This is only useful
352 in older systems without a pci bridge. Also, it only
353 impacts devices that the BIOS doesn't assign to, typically
354 CardBus bridges. The default <value> is 0x80000000, but
355 some systems need values like 0xf0000000, 0xfc000000 or
356 0xfe000000 may be suitable for older systems (the older
357 the system, the higher the number typically should be).
359 set hw.pci.enable_io_modes=<value>
361 Enable PCI resources which are left off by some BIOSes
362 or are not enabled correctly by the device driver.
364 value is 1 (default), but this may cause problems with
365 some peripherals. Set to 0 to disable.
367 ################################################################################
368 # Tshow DShow the values of variables
372 Displays the value of <variable>, or all variables if not specified.
373 Multiple paths can be separated with a semicolon.
375 ################################################################################
376 # Tinclude DRead commands from a script file
378 include <filename> [<filename> ...]
380 The entire contents of <filename> are read into memory before executing
381 commands, so it is safe to source a file from removable media.
383 ################################################################################
384 # Tread DRead input from the terminal
386 read [-t <value>] [-p <prompt>] [<variable name>]
388 The read command reads a line of input from the terminal. If the
389 -t argument is specified, it will return nothing if no input has been
390 received after <value> seconds. (Any keypress will cancel the
393 If -p is specified, <prompt> is printed before reading input. No
394 newline is emitted after the prompt.
396 If a variable name is supplied, the variable is set to the value read,
397 less any terminating newline.
399 ################################################################################
400 # Tunload DRemove all modules from memory
404 This command removes any kernel and all loaded modules from memory.
406 ################################################################################
407 # Tunmap-vdisk DUnmap virtual disk
411 Delete virtual disk mapping.
413 ################################################################################
414 # Tunset DUnset a variable
416 unset <variable name>
418 If allowed, the named variable's value is discarded and the variable
421 ################################################################################