xref: /freebsd/stand/common/help.common (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
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 debugging 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_dfltroot DUse default root file system
174
175	set boot_dfltroot
176
177	Instructs the kernel to mount the statically compiled-in root
178	file system.
179
180################################################################################
181# Tset Sboot_gdb DSelect gdb-remote mode for the kernel debugger
182
183	set boot_gdb
184
185	Selects gdb-remote mode for the kernel debugger by default.
186
187################################################################################
188# Tset Sboot_multicons DUse multiple consoles
189
190	set boot_multicons
191
192	Enables multiple console support in the kernel early on boot.
193	In a running system, console configuration can be manipulated
194	by the conscontrol(8) utility.
195
196################################################################################
197# Tset Sboot_mute DMute the console
198
199	set boot_mute
200
201	All console output is suppressed when console is muted.
202	In a running system, the state of console muting can be
203	manipulated by the conscontrol(8) utility.
204
205################################################################################
206# Tset Sboot_pause DPause after each line during device probing
207
208	set boot_pause
209
210	During the device probe, pause after each line is printed.
211
212################################################################################
213# Tset Sboot_serial DUse serial console
214
215	set boot_serial
216
217	Force the use of a serial console even when an internal console
218	is present.
219
220################################################################################
221# Tset Sboot_single DStart system in single-user mode
222
223	set boot_single
224
225	Prevents the kernel from initiating a multi-user startup; instead,
226	a single-user mode will be entered when the kernel has finished
227	device probes.
228
229################################################################################
230# Tset Sboot_verbose DVerbose boot messages
231
232	set boot_verbose
233
234	Setting this variable causes extra debugging information to be printed
235	by the kernel during the boot phase.
236
237################################################################################
238# Tset Sconsole DSet the current console
239
240	set console[=<value>]
241
242	Sets the current console.  If <value> is omitted, a list of valid
243	consoles will be displayed.
244
245################################################################################
246# Tset Scurrdev DSet the current device
247
248	set currdev=<device>
249
250	Selects the default device.  See lsdev for available devices.
251
252################################################################################
253# Tset Sinit_path DSet the list of init candidates
254
255	set init_path=<path>[:<path>...]
256
257	Sets the list of binaries which the kernel will try to run as initial
258	process.
259
260
261################################################################################
262# Tset Smodule_path DSet the module search path
263
264	set module_path=<path>[;<path>...]
265
266	Sets the list of directories which will be searched in for modules
267	named in a load command or implicitly required by a dependency. The
268	default module_path is "/boot/modules" with the kernel directory
269	prepended.
270
271################################################################################
272# Tset Sprompt DSet the command prompt
273
274	set prompt=<value>
275
276	The command prompt is displayed when the loader is waiting for input.
277	Variable substitution is performed on the prompt.  The default
278	prompt can be set with:
279
280		set prompt=\${interpret}
281
282################################################################################
283# Tset Srootdev DSet the root filesystem
284
285	set rootdev=<path>
286
287	By default the value of $currdev is used to set the root filesystem
288	when the kernel is booted.  This can be overridden by setting
289	$rootdev explicitly.
290
291################################################################################
292# Tset Stunables DSet kernel tunable values
293
294	Various kernel tunable parameters can be overridden by specifying new
295	values in the environment.
296
297	set kern.ipc.nmbclusters=<value>
298
299		Set the number of mbuf clusters to be allocated.  The value
300		cannot be set below the default determined when the kernel
301		was compiled.
302
303	set kern.ipc.nsfbufs=<value>		NSFBUFS
304
305		Set the number of sendfile buffers to be allocated.  This
306		overrides the value determined when the kernel was compiled.
307
308	set vm.kmem_size=<value>		VM_KMEM_SIZE
309
310		Sets the size of kernel memory (bytes).  This overrides
311		the value determined when the kernel was compiled.
312
313	set machdep.disable_mtrrs=1
314
315		Disable the use of i686 MTRRs (i386 only)
316
317	set net.inet.tcp.tcbhashsize=<value>	TCBHASHSIZE
318
319		Overrides the compile-time set value of TCBHASHSIZE or
320		the preset default of 512.  Must be a power of 2.
321
322	hw.syscons.sc_no_suspend_vtswitch=<value>
323
324		Disable VT switching on suspend.
325
326		value is 0 (default) or non-zero to enable.
327
328	set hw.physmem=<value>			MAXMEM (i386 only)
329
330		Limits the amount of physical memory space available to
331		the system to <value> bytes.  <value> may have a k, M or G
332		suffix to indicate kilobytes, megabytes and gigabytes
333		respectively.  Note that the current i386 architecture
334		limits this value to 4GB.
335
336		On systems where memory cannot be accurately probed,
337		this option provides a hint as to the actual size of
338		system memory (which will be tested before use).
339
340	set hw.{acpi,pci}.host_start_mem=<value>
341
342		Sets the lowest address that the pci code will assign
343		when it doesn't have other information about the address
344		to assign (like from a pci bridge).  This is only useful
345		in older systems without a pci bridge.  Also, it only
346		impacts devices that the BIOS doesn't assign to, typically
347		CardBus bridges.  The default <value> is 0x80000000, but
348		some systems need values like 0xf0000000, 0xfc000000 or
349		0xfe000000 may be suitable for older systems (the older
350		the system, the higher the number typically should be).
351
352	set hw.pci.enable_io_modes=<value>
353
354		Enable PCI resources which are left off by some BIOSes
355		or are not enabled correctly by the device driver.
356
357		value is 1 (default), but this may cause problems with
358		some peripherals.  Set to 0 to disable.
359
360################################################################################
361# Tshow DShow the values of variables
362
363	show [<variable>]
364
365	Displays the value of <variable>, or all variables if not specified.
366	Multiple paths can be separated with a semicolon.
367
368################################################################################
369# Tinclude DRead commands from a script file
370
371	include <filename> [<filename> ...]
372
373	The entire contents of <filename> are read into memory before executing
374	commands, so it is safe to source a file from removable media.
375
376################################################################################
377# Tread DRead input from the terminal
378
379	read [-t <value>] [-p <prompt>] [<variable name>]
380
381	The read command reads a line of input from the terminal.  If the
382	-t argument is specified, it will return nothing if no input has been
383	received after <value> seconds.  (Any keypress will cancel the
384	timeout).
385
386	If -p is specified, <prompt> is printed before reading input. No
387	newline is emitted after the prompt.
388
389	If a variable name is supplied, the variable is set to the value read,
390	less any terminating newline.
391
392################################################################################
393# Tunload DRemove all modules from memory
394
395	unload
396
397	This command removes any kernel and all loaded modules from memory.
398
399################################################################################
400# Tunset DUnset a variable
401
402	unset <variable name>
403
404	If allowed, the named variable's value is discarded and the variable
405	is removed.
406
407################################################################################
408