help.common revision 1.2 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
137 ################################################################################
138 # Tset Sbootfile DSet the default boot file set
139
140 set bootfile=<filename>[;<filename>...]
141
142 Sets the default set of kernel boot filename(s). It may be overridden
143 by setting the bootfile variable to a semicolon-separated list of
144 filenames, each of which will be searched for in the module_path
145 directories. The default bootfile set is "kernel".
146
147 ################################################################################
148 # Tset Sboot_askname DPrompt for root device
149
150 set boot_askname
151
152 Instructs the kernel to prompt the user for the name of the root device
153 when the kernel is booted.
154
155 ################################################################################
156 # Tset Sboot_cdrom DMount root file system from CD-ROM
157
158 set boot_cdrom
159
160 Instructs the kernel to try to mount the root file system from CD-ROM.
161
162 ################################################################################
163 # Tset Sboot_ddb DDrop to the kernel debugger (DDB)
164
165 set boot_ddb
166
167 Instructs the kernel to start in the DDB debugger, rather than
168 proceeding to initialize when booted.
169
170 ################################################################################
171 # Tset Sboot_gdb DSelect gdb-remote mode for the kernel debugger
172
173 set boot_gdb
174
175 Selects gdb-remote mode for the kernel debugger by default.
176
177 ################################################################################
178 # Tset Sboot_multicons DUse multiple consoles
179
180 set boot_multicons
181
182 Enables multiple console support in the kernel early on boot.
183 In a running system, console configuration can be manipulated
184 by the conscontrol(8) utility.
185
186 ################################################################################
187 # Tset Sboot_serial DUse serial console
188
189 set boot_serial
190
191 Force the use of a serial console even when an internal console
192 is present.
193
194 ################################################################################
195 # Tset Sboot_single DStart system in single-user mode
196
197 set boot_single
198
199 Prevents the kernel from initiating a multi-user startup; instead,
200 a single-user mode will be entered when the kernel has finished
201 device probes.
202
203 ################################################################################
204 # Tset Sboot_verbose DVerbose boot messages
205
206 set boot_verbose
207
208 Setting this variable causes extra debugging information to be printed
209 by the kernel during the boot phase.
210
211 ################################################################################
212 # Tset Sconsole DSet the current console
213
214 set console[=<value>]
215
216 Sets the current console. If <value> is omitted, a list of valid
217 consoles will be displayed.
218
219 ################################################################################
220 # Tset Scurrdev DSet the current device
221
222 set currdev=<device>
223
224 Selects the default device. Syntax for devices is odd.
225
226 ################################################################################
227 # Tset Sinit_path DSet the list of init candidates
228
229 set init_path=<path>[:<path>...]
230
231 Sets the list of binaries which the kernel will try to run as initial
232 process.
233
234
235 ################################################################################
236 # Tset Smodule_path DSet the module search path
237
238 set module_path=<path>[;<path>...]
239
240 Sets the list of directories which will be searched in for modules
241 named in a load command or implicitly required by a dependency. The
242 default module_path is "/boot/modules" with the kernel directory
243 prepended.
244
245 ################################################################################
246 # Tset Sprompt DSet the command prompt
247
248 set prompt=<value>
249
250 The command prompt is displayed when the loader is waiting for input.
251 Variable substitution is performed on the prompt. The default
252 prompt can be set with:
253
254 set prompt=\${interpret}
255
256 ################################################################################
257 # Tset Srootdev DSet the root filesystem
258
259 set rootdev=<path>
260
261 By default the value of $currdev is used to set the root filesystem
262 when the kernel is booted. This can be overridden by setting
263 $rootdev explicitly.
264
265 ################################################################################
266 # Tset Stunables DSet kernel tunable values
267
268 Various kernel tunable parameters can be overridden by specifying new
269 values in the environment.
270
271 set kern.ipc.nmbclusters=<value>
272
273 Set the number of mbuf clusters to be allocated. The value
274 cannot be set below the default determined when the kernel
275 was compiled.
276
277 set kern.ipc.nsfbufs=<value> NSFBUFS
278
279 Set the number of sendfile buffers to be allocated. This
280 overrides the value determined when the kernel was compiled.
281
282 set vm.kmem_size=<value> VM_KMEM_SIZE
283
284 Sets the size of kernel memory (bytes). This overrides
285 the value determined when the kernel was compiled.
286
287 set machdep.disable_mtrrs=1
288
289 Disable the use of i686 MTRRs (i386 only)
290
291 set net.inet.tcp.tcbhashsize=<value> TCBHASHSIZE
292
293 Overrides the compile-time set value of TCBHASHSIZE or
294 the preset default of 512. Must be a power of 2.
295
296 hw.syscons.sc_no_suspend_vtswitch=<value>
297
298 Disable VT switching on suspend.
299
300 value is 0 (default) or non-zero to enable.
301
302 set hw.physmem=<value> MAXMEM (i386 only)
303
304 Limits the amount of physical memory space available to
305 the system to <value> bytes. <value> may have a k, M or G
306 suffix to indicate kilobytes, megabytes and gigabytes
307 respectively. Note that the current i386 architecture
308 limits this value to 4GB.
309
310 On systems where memory cannot be accurately probed,
311 this option provides a hint as to the actual size of
312 system memory (which will be tested before use).
313
314 set hw.{acpi,pci}.host_start_mem=<value>
315
316 Sets the lowest address that the pci code will assign
317 when it doesn't have other information about the address
318 to assign (like from a pci bridge). This is only useful
319 in older systems without a pci bridge. Also, it only
320 impacts devices that the BIOS doesn't assign to, typically
321 CardBus bridges. The default <value> is 0x80000000, but
322 some systems need values like 0xf0000000, 0xfc000000 or
323 0xfe000000 may be suitable for older systems (the older
324 the system, the higher the number typically should be).
325
326 set hw.pci.enable_io_modes=<value>
327
328 Enable PCI resources which are left off by some BIOSes
329 or are not enabled correctly by the device driver.
330
331 value is 1 (default), but this may cause problems with
332 some peripherals. Set to 0 to disable.
333
334 ################################################################################
335 # Tshow DShow the values of variables
336
337 show [<variable>]
338
339 Displays the value of <variable>, or all variables if not specified.
340 Multiple paths can be separated with a semicolon.
341
342 ################################################################################
343 # Tinclude DRead commands from a script file
344
345 include <filename> [<filename> ...]
346
347 The entire contents of <filename> are read into memory before executing
348 commands, so it is safe to source a file from removable media.
349
350 ################################################################################
351 # Tread DRead input from the terminal
352
353 read [-t <value>] [-p <prompt>] [<variable name>]
354
355 The read command reads a line of input from the terminal. If the
356 -t argument is specified, it will return nothing if no input has been
357 received after <value> seconds. (Any keypress will cancel the
358 timeout).
359
360 If -p is specified, <prompt> is printed before reading input. No
361 newline is emitted after the prompt.
362
363 If a variable name is supplied, the variable is set to the value read,
364 less any terminating newline.
365
366 ################################################################################
367 # Tunload DRemove all modules from memory
368
369 unload
370
371 This command removes any kernel and all loaded modules from memory.
372
373 ################################################################################
374 # Tunset DUnset a variable
375
376 unset <variable name>
377
378 If allowed, the named variable's value is discarded and the variable
379 is removed.
380
381 ################################################################################
382