1 ################################################################################
2 # Thelp DDisplay command help
4 help [topic [subtopic]]
8 The help command displays help on commands and their usage.
10 In command help, a term enclosed with <...> indicates a value as
11 described by the term. A term enclosed with [...] is optional,
12 and may not be required by all forms of the command.
14 Some commands may not be available. Use the '?' command to list
15 most available commands.
17 If needed, disable the use of ACPI with:
20 set hint.acpi.0.disabled="1"
22 ################################################################################
23 # Tautoboot DBoot after a delay
25 autoboot [<delay> [<prompt>]]
27 Displays <prompt> or a default prompt, and counts down <delay> seconds
28 before attempting to boot. If <delay> is not specified, the default
31 ################################################################################
32 # Tboot DBoot immediately
34 boot [<kernelname>] [-<arg> ...]
36 Boot the system. If arguments are specified, they are added to the
37 arguments for the kernel. If <kernelname> is specified, and a kernel
38 has not already been loaded, it will be booted instead of the default
41 ################################################################################
42 # Techo DEcho arguments
46 Emits <message>, with no trailing newline if -n is specified. This is
47 most useful in conjunction with scripts and the '@' line prefix.
49 Variables are substituted by prefixing them with $, eg.
51 echo Current device is $currdev
53 will print the current device.
55 ################################################################################
56 # Tload DLoad a kernel or module
58 load [-t <type>] <filename>
60 Loads the module contained in <filename> into memory. If no other
61 modules are loaded, <filename> must be a kernel or the command will
64 If -t is specified, the module is loaded as raw data of <type>, for
65 later use by the kernel or other modules. <type> may be any string.
67 ################################################################################
72 Displays a listing of files in the directory <path>, or the root
73 directory of the current device if <path> is not specified.
75 The -l argument displays file sizes as well; the process of obtaining
76 file sizes on some media may be very slow.
78 ################################################################################
79 # Tlsdev DList devices
83 List all of the devices from which it may be possible to load modules.
84 If -v is specified, print more details.
86 ################################################################################
87 # Tlsmod DList modules
91 List loaded modules. If [-v] is specified, print more details.
93 ################################################################################
96 more <filename> [<filename> ...]
98 Show contents of text files. When displaying the contents of more,
99 than one file, if the user elects to quit displaying a file, the
100 remaining files will not be shown.
102 ################################################################################
103 # Tpnpscan DScan for PnP devices
107 Scan for Plug-and-Play devices. This command is normally automatically
108 run as part of the boot process, in order to dynamically load modules
109 required for system operation.
111 If the -v argument is specified, details on the devices found will
114 ################################################################################
115 # Tset DSet a variable
118 set <variable name>=<value>
120 The set command is used to set variables.
122 ################################################################################
123 # Tset Sautoboot_delay DSet the default autoboot delay
125 set autoboot_delay=<value>
127 Sets the default delay for the autoboot command to <value> seconds.
129 ################################################################################
130 # Tset Sbootfile DSet the default boot file set
132 set bootfile=<filename>[;<filename>...]
134 Sets the default set of kernel boot filename(s). It may be overridden
135 by setting the bootfile variable to a semicolon-separated list of
136 filenames, each of which will be searched for in the module_path
137 directories. The default bootfile set is "kernel".
139 ################################################################################
140 # Tset Sboot_askname DPrompt for root device
144 Instructs the kernel to prompt the user for the name of the root device
145 when the kernel is booted.
147 ################################################################################
148 # Tset Sboot_ddb DDrop to the kernel debugger (DDB)
152 Instructs the kernel to start in the DDB debugger, rather than
153 proceeding to initialise when booted.
155 ################################################################################
156 # Tset Sboot_gdb DSelect gdb-remote mode
160 Selects gdb-remote mode for the kernel debugger by default.
162 ################################################################################
163 # Tset Sboot_single DStart system in single-user mode
167 Prevents the kernel from initiating a multi-user startup, single-user
168 mode will be entered when the kernel has finished device probes.
170 ################################################################################
171 # Tset Sboot_verbose DVerbose boot messages
175 Setting this variable causes extra debugging information to be printed
176 by the kernel during the boot phase.
178 ################################################################################
179 # Tset Sconsole DSet the current console
181 set console[=<value>]
183 Sets the current console. If <value> is omitted, a list of valid
184 consoles will be displayed.
186 ################################################################################
187 # Tset Scurrdev DSet the current device
191 Selects the default device. See lsdev for available devices.
193 ################################################################################
194 # Tset Sinit_path DSet the list of init candidates
196 set init_path=<path>[:<path>...]
198 Sets the list of binaries which the kernel will try to run as initial
202 ################################################################################
203 # Tset Smodule_path DSet the module search path
205 set module_path=<path>[;<path>...]
207 Sets the list of directories which will be searched in for modules
208 named in a load command or implicitly required by a dependency. The
209 default module_path is "/boot;/boot/modules;/;/modules".
211 ################################################################################
212 # Tset Sprompt DSet the command prompt
216 The command prompt is displayed when the loader is waiting for input.
217 Variable substitution is performed on the prompt. The default
218 prompt can be set with:
220 set prompt=\${interpret}
222 ################################################################################
223 # Tset Srootdev DSet the root filesystem
227 By default the value of $currdev is used to set the root filesystem
228 when the kernel is booted. This can be overridden by setting
231 ################################################################################
232 # Tset Stunables DSet kernel tunable values
234 Various kernel tunable parameters can be overridden by specifying new
235 values in the environment.
237 set kern.ipc.nmbclusters=<value> NMBCLUSTERS
239 Set the number of mbuf clusters to be allocated. The value
240 cannot be set below the default determined when the kernel
243 set kern.ipc.nsfbufs=<value> NSFBUFS
245 Set the number of sendfile buffers to be allocated. This
246 overrides the value determined when the kernel was compiled.
248 set kern.vm.kmem.size=<value>
250 Sets the size of kernel memory (bytes). This overrides
251 the value determined when the kernel was compiled.
253 set machdep.disable_mtrrs=1
255 Disable the use of i686 MTRRs (i386 only)
257 set net.inet.tcp.tcbhashsize=<value> TCBHASHSIZE
259 Overrides the compile-time set value of TCBHASHSIZE or
260 the preset default of 512. Must be a power of 2.
262 hw.syscons.sc_no_suspend_vtswitch=<value>
264 Disable VT switching on suspend.
266 value is 0 (default) or non-zero to enable.
268 set hw.physmem=<value> MAXMEM (i386 only)
270 Limits the amount of physical memory space available to
271 the system to <value> bytes. <value> may have a k, M or G
272 suffix to indicate kilobytes, megabytes and gigabytes
273 respectively. Note that the current i386 architecture
274 limits this value to 4GB.
276 On systems where memory cannot be accurately probed,
277 this option provides a hint as to the actual size of
278 system memory (which will be tested before use).
280 set hw.pci.allow_unsupported_io_range=<value>
282 Allow the PCI Bridge to pass through an unsupported
283 memory range assigned by the BIOS.
285 value is 0 (default) or non-zero to enable.
287 set hw.pci.enable_io_modes=<value>
289 Enable PCI resources which are left off by some BIOSes
290 or are not enabled correctly by the device driver.
292 value is 1 (default), but this may cause problems with
293 some peripherals. Set to 0 to disable.
295 ################################################################################
296 # Tshow DShow the values of variables
300 Displays the value of <variable>, or all variables if not specified.
301 Multiple paths can be separated with a semicolon.
303 ################################################################################
304 # Tinclude DRead commands from a script file
306 include <filename> [<filename> ...]
308 The entire contents of <filename> are read into memory before executing
309 commands, so it is safe to source a file from removable media.
311 ################################################################################
312 # Tread DRead input from the terminal
314 read [-t <value>] [-p <prompt>] [<variable name>]
316 The read command reads a line of input from the terminal. If the
317 -t argument is specified, it will return nothing if no input has been
318 received after <value> seconds. (Any keypress will cancel the
321 If -p is specified, <prompt> is printed before reading input. No
322 newline is emitted after the prompt.
324 If a variable name is supplied, the variable is set to the value read,
325 less any terminating newline.
327 ################################################################################
328 # Tunload DRemove all modules from memory
332 This command removes any kernel and all loaded modules from memory.
334 ################################################################################
335 # Tunset DUnset a variable
337 unset <variable name>
339 If allowed, the named variable's value is discarded and the variable
342 ################################################################################