1devlinks(1M) System Administration Commands devlinks(1M)
2
6 devlinks - adds /dev entries for miscellaneous devices and pseudo-
7 devices
8
10 /usr/sbin/devlinks [-d] [-r rootdir] [-t table-file]
11
14 devfsadm(1M) is now the preferred command for /dev and /devices and
15 should be used instead of devlinks.
16 devlinks creates symbolic links from the /dev directory tree to the
19 actual block- and character-special device nodes under the /devices
20 directory tree. The links are created according to specifications found
21 in the table-file (by default /etc/devlink.tab).
22 devlinks is called each time the system is reconfiguration-booted, and
25 can only be run after drvconfig(1M) is run.
26 The table-file (normally /etc/devlink.tab) is an ASCII file, with one
29 line per record. Comment lines, which must contain a hash character
30 (`#') as their first character, are allowed. Each entry must contain at
31 least two fields, but may contain three fields. Fields are separated by
32 single TAB characters.
33 The fields are:
36 devfs-spec Specification of devinfo nodes that will have links
38 created for them. This specification consists of one
39 or more keyword-value pairs, where the keyword is
40 separated from the value by an equal-sign (`='), and
41 keyword-value pairs are separated from one another by
42 semicolons.
43 The possible keywords are:
45 type The devinfo device type. Possible values
47 are specified in ddi_cre‐
48 ate_minor_node(9F)
49 name The name of the node. This is the portion
52 of the /devices tree entry name that
53 occurs before the first `@' or `:' char‐
54 acter.
55 addr[n] The address portion of a node name. This
58 is the portion of a node name that occurs
59 between the `@' and the `:' characters.
60 It is possible that a node may have a
61 name without an address part, which is
62 the case for many of the pseudo-device
63 nodes. If a number is given after the
64 addr it specifies a match of a particular
65 comma-separated subfield of the address
66 field: addr1 matches the first subfield,
67 addr2 matches the second, and so on.
68 addr0 is the same as addr and matches the
69 whole field.
70 minor[n] The minor portion of a node name − the
73 portion of the name after the `:'. As
74 with addr above, a number after the minor
75 keyword specifies a subfield to match.
76 Of these four specifications, only the type specifi‐
78 cation must always be present.
79 name Specification of the /dev links that correspond to
82 the devinfo nodes. This field allows devlinks to
83 determine matching /dev names for the /devices nodes
84 it has found. The specification of this field uses
85 escape-sequences to allow portions of the /devices
86 name to be included in the /dev name, or to allow a
87 counter to be used in creating node names. If a
88 counter is used to create a name, the portion of the
89 name before the counter must be specified absolutely,
90 and all names in the /dev/-subdirectory that match
91 (up to and including the counter) are considered to
92 be subdevices of the same device. This means that
93 they should all point to the same directory, name and
94 address under the /devices/-tree
95 The possible escape-sequences are:
97 \D Substitute the device-name (name) portion of
99 the corresponding devinfo node-name.
100 \An Substitute the nth component of the address
103 component of the corresponding devinfo node
104 name. Sub-components are separated by commas,
105 and sub-component 0 is the whole address com‐
106 ponent.
107 \Mn Substitute the nth sub-component of the minor
110 component of the corresponding devinfo node
111 name. Sub-components are separated by commas,
112 and sub-component 0 is the whole minor compo‐
113 nent.
114 \Nn Substitute the value of a 'counter' starting
117 at n. There can be only one counter for each
118 dev-spec, and counter-values will be selected
119 so they are as low as possible while not col‐
120 liding with already-existing link names.
121 In a dev-spec the counter sequence should not
123 be followed by a digit, either explicitly or
124 as a result of another escape-sequence expan‐
125 sion. If this occurs, it would not be possi‐
126 ble to correctly match already-existing links
127 to their counter entries, since it would not
128 be possible to unambiguously parse the
129 already-existing /dev-name.
130 extra-dev-link Optional specification of an extra /dev link that
134 points to the initial /dev link (specified in field
135 2). This field may contain a counter escape-sequence
136 (as described for the dev-spec field) but may not
137 contain any of the other escape-sequences. It pro‐
138 vides a way to specify an alias of a particular /dev
139 name.
140
143 The following options are supported:
144 -d Debugging mode − print out all devinfo nodes found,
146 and indicate what links would be created, but do not
147 do anything.
148 -r rootdir Use rootdir as the root of the /dev and /devices
151 directories under which the device nodes and links are
152 created. Changing the root directory does not change
153 the location of the /etc/devlink.tab default table,
154 nor is the root directory applied to the filename sup‐
155 plied to the -t option.
156 -t table-file Set the table file used by devlinks to specify the
159 links that must be created. If this option is not
160 given, /etc/devlink.tab is used. This option gives a
161 way to instruct devlinks just to perform a particular
162 piece of work, since just the links-types that
163 devlinks is supposed to create can be specified in a
164 command-file and fed to devlinks.
165
168 If devlinks finds an error in a line of the table-file it prints a
169 warning message on its standard output and goes on to the next line in
170 the table-file without performing any of the actions specified by the
171 erroneous rule.
172 If it cannot create a link for some filesystem-related reason it prints
175 an error-message and continues with the current rule.
176 If it cannot read necessary data it prints an error message and contin‐
179 ues with the next table-file line.
180
182 Example 1 Using the /etc/devlink.tab Fields
183 The following are examples of the /etc/devlink.tab fields:
186 type=pseudo;name=win win\M0
189 type=ddi_display framebuffer/\M0 fb\N0
190 The first example states that all devices of type pseudo with a name
194 component of win will be linked to /dev/winx, where x is the minor-com‐
195 ponent of the devinfo-name (this is always a single-digit number for
196 the win driver).
197 The second example states that all devinfo nodes of type ddi_display
201 will be linked to entries under the /dev/framebuffer directory, with
202 names identical to the entire minor component of the /devices name. In
203 addition an extra link will be created pointing from /dev/fbn to the
204 entry under /dev/framebuffer. This entry will use a counter to end the
205 name.
206
209 /dev entries for the miscellaneous devices for general
210 use
211 /devices device nodes
214 /etc/devlink.tab the default rule-file
217
220 See attributes(5) for descriptions of the following attributes:
221 ┌─────────────────────────────┬─────────────────────────────┐
226 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
227 ├─────────────────────────────┼─────────────────────────────┤
228 │Availability │SUNWcsu │
229 └─────────────────────────────┴─────────────────────────────┘
230
232 devfsadm(1M), attributes(5), devfs(7FS), ddi_create_minor_node(9F)
233
235 It is very easy to construct mutually-contradictory link specifica‐
236 tions, or specifications that can never be matched. The program does
237 not check for these conditions.
238SunOS 5.11 15 Jul 2002 devlinks(1M)