1 ################################################################################
2 # Thelp DDisplay command help
4 help [topic [subtopic]]
8 The help command displays help on commands and their usage.
9 $DragonFly: src/sys/boot/common/help.common,v 1.6 2008/09/01 19:39:45 dillon Exp $
11 In command help, a term enclosed with <...> indicates a value as
12 described by the term. A term enclosed with [...] is optional,
13 and may not be required by all forms of the command.
15 Some commands may not be available. Use the '?' command to list
16 most available commands.
18 If needed, disable the use of ACPI with:
21 set hint.acpi.0.disabled="1"
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 # Techo DEcho arguments
47 Emits <message>, with no trailing newline if -n is specified. This is
48 most useful in conjunction with scripts and the '@' line prefix.
50 Variables are substituted by prefixing them with $, eg.
52 echo Current device is $currdev
54 will print the current device.
56 ################################################################################
57 # Tload DLoad a kernel or module
59 load [-t <type>] <filename>
61 Loads the module contained in <filename> into memory. If no other
62 modules are loaded, <filename> must be a kernel or the command will
65 If -t is specified, the module is loaded as raw data of <type>, for
66 later use by the kernel or other modules. <type> may be any string.
68 ################################################################################
73 Displays a listing of files in the directory <path>, or the root
74 directory of the current device if <path> is not specified.
76 The -l argument displays file sizes as well; the process of obtaining
77 file sizes on some media may be very slow.
79 ################################################################################
80 # Tlsdev DList devices
84 List all of the devices from which it may be possible to load modules.
85 If -v is specified, print more details.
87 ################################################################################
88 # Tlsmod DList modules
92 List loaded modules. If [-v] is specified, print more details.
94 ################################################################################
97 more <filename> [<filename> ...]
99 Show contents of text files. When displaying the contents of more,
100 than one file, if the user elects to quit displaying a file, the
101 remaining files will not be shown.
103 ################################################################################
104 # Tpnpscan DScan for PnP devices
108 Scan for Plug-and-Play devices. This command is normally automatically
109 run as part of the boot process, in order to dynamically load modules
110 required for system operation.
112 If the -v argument is specified, details on the devices found will
115 ################################################################################
116 # Tset DSet a variable
119 set <variable name>=<value>
121 The set command is used to set variables.
123 ################################################################################
124 # Tset Sautoboot_delay DSet the default autoboot delay
126 set autoboot_delay=<value>
128 Sets the default delay for the autoboot command to <value> seconds.
130 ################################################################################
131 # Tset Sbootfile DSet the default boot file set
133 set bootfile=<filename>[;<filename>...]
135 Sets the default set of kernel boot filename(s). It may be overridden
136 by setting the bootfile variable to a semicolon-separated list of
137 filenames, each of which will be searched for in the module_path
138 directories. The default bootfile set is "kernel".
140 ################################################################################
141 # Tset Sboot_askname DPrompt for root device
145 Instructs the kernel to prompt the user for the name of the root device
146 when the kernel is booted.
148 ################################################################################
149 # Tset Sboot_ddb DDrop to the kernel debugger (DDB)
153 Instructs the kernel to start in the DDB debugger, rather than
154 proceeding to initialise when booted.
156 ################################################################################
157 # Tset Sboot_gdb DSelect gdb-remote mode
161 Selects gdb-remote mode for the kernel debugger by default.
163 ################################################################################
164 # Tset Sboot_single DStart system in single-user mode
168 Prevents the kernel from initiating a multi-user startup, single-user
169 mode will be entered when the kernel has finished device probes.
171 ################################################################################
172 # Tset Sboot_verbose DVerbose boot messages
176 Setting this variable causes extra debugging information to be printed
177 by the kernel during the boot phase.
179 ################################################################################
180 # Tset Sconsole DSet the current console
182 set console[=<value>]
184 Sets the current console. If <value> is omitted, a list of valid
185 consoles will be displayed.
187 ################################################################################
188 # Tset Scurrdev DSet the current device
192 Selects the default device. See lsdev for available devices.
194 ################################################################################
195 # Tset Sinit_path DSet the list of init candidates
197 set init_path=<path>[:<path>...]
199 Sets the list of binaries which the kernel will try to run as initial
203 ################################################################################
204 # Tset Smodule_path DSet the module search path
206 set module_path=<path>[;<path>...]
208 Sets the list of directories which will be searched in for modules
209 named in a load command or implicitly required by a dependency. The
210 default module_path is "/boot;/boot/modules;/;/modules".
212 ################################################################################
213 # Tset Sprompt DSet the command prompt
217 The command prompt is displayed when the loader is waiting for input.
218 Variable substitution is performed on the prompt. The default
219 prompt can be set with:
221 set prompt=\${interpret}
223 ################################################################################
224 # Tset Srootdev DSet the root filesystem
228 By default the value of $currdev is used to set the root filesystem
229 when the kernel is booted. This can be overridden by setting
232 ################################################################################
233 # Tset Stunables DSet kernel tunable values
235 Various kernel tunable parameters can be overridden by specifying new
236 values in the environment.
238 set kern.ipc.nmbclusters=<value> NMBCLUSTERS
240 Set the number of mbuf clusters to be allocated. The value
241 cannot be set below the default determined when the kernel
244 set kern.ipc.nsfbufs=<value> NSFBUFS
246 Set the number of sendfile buffers to be allocated. This
247 overrides the value determined when the kernel was compiled.
249 set kern.vm.kmem.size=<value>
251 Sets the size of kernel memory (bytes). This overrides
252 the value determined when the kernel was compiled.
254 set machdep.disable_mtrrs=1
256 Disable the use of i686 MTRRs (i386 only)
258 set net.inet.tcp.tcbhashsize=<value> TCBHASHSIZE
260 Overrides the compile-time set value of TCBHASHSIZE or
261 the preset default of 512. Must be a power of 2.
263 hw.syscons.sc_no_suspend_vtswitch=<value>
265 Disable VT switching on suspend.
267 value is 0 (default) or non-zero to enable.
269 set hw.physmem=<value> MAXMEM (i386 only)
271 Limits the amount of physical memory space available to
272 the system to <value> bytes. <value> may have a k, M or G
273 suffix to indicate kilobytes, megabytes and gigabytes
274 respectively. Note that the current i386 architecture
275 limits this value to 4GB.
277 On systems where memory cannot be accurately probed,
278 this option provides a hint as to the actual size of
279 system memory (which will be tested before use).
281 set hw.pci.allow_unsupported_io_range=<value>
283 Allow the PCI Bridge to pass through an unsupported
284 memory range assigned by the BIOS.
286 value is 0 (default) or non-zero to enable.
288 set hw.pci.enable_io_modes=<value>
290 Enable PCI resources which are left off by some BIOSes
291 or are not enabled correctly by the device driver.
293 value is 1 (default), but this may cause problems with
294 some peripherals. Set to 0 to disable.
296 ################################################################################
297 # Tshow DShow the values of variables
301 Displays the value of <variable>, or all variables if not specified.
302 Multiple paths can be separated with a semicolon.
304 ################################################################################
305 # Tinclude DRead commands from a script file
307 include <filename> [<filename> ...]
309 The entire contents of <filename> are read into memory before executing
310 commands, so it is safe to source a file from removable media.
312 ################################################################################
313 # Tread DRead input from the terminal
315 read [-t <value>] [-p <prompt>] [<variable name>]
317 The read command reads a line of input from the terminal. If the
318 -t argument is specified, it will return nothing if no input has been
319 received after <value> seconds. (Any keypress will cancel the
322 If -p is specified, <prompt> is printed before reading input. No
323 newline is emitted after the prompt.
325 If a variable name is supplied, the variable is set to the value read,
326 less any terminating newline.
328 ################################################################################
329 # Tunload DRemove all modules from memory
333 This command removes any kernel and all loaded modules from memory.
335 ################################################################################
336 # Tunset DUnset a variable
338 unset <variable name>
340 If allowed, the named variable's value is discarded and the variable
343 ################################################################################