1 VT(7I) Ioctl Requests VT(7I)
2
3 NAME
4 vt - Solaris virtual console interface
5
6 SYNOPSIS
7 #include <sys/kd.h>
8 #include <sys/vt.h>
9
10 DESCRIPTION
11 The virtual console device driver -- also known as virtual terminal (VT)
12 -- is a layer of management functions that provides facilities to support
13 and switch between multiple screen faces on a single physical device.
14
15 VT's are accessed in the same way as other devices. The open(2) system
16 call is used to open the virtual console and read(2), write(2) and
17 ioctl(2) are used in the normal way and support the functionality of the
18 underlying device. In addition, some virtual console-specific ioctls are
19 provided and described below.
20
21 The VT provides a link between different screen faces and the device.
22 The active virtual console corresponds to the currently visible screen
23 face. Device input is directed to the active console and any device-
24 specific modes that change on a per virtual terminal basis are set to the
25 characteristics associated with the active console.
26
27 You manage VT's by intercepting keyboard sequences ("hot key"). To
28 maintain consistency with Xserver, the virtual console device driver
29 supports the Ctrl, Alt, F# and arrow keys.
30
31 The sequence AltL + F# (where AltL represents the left Alt key and F#
32 represents function keys 1 through 12) is used to select virtual console
33 1-12. The sequence AltGraph + F# (where AltGraph represents the right
34 Alt key and F# represent function keys 1 through 12) is for virtual
35 console 13-24. Alt + F1 chooses the system console (also known as
36 virtual console 1). The sequence Alt + -> (where "->" represents the
37 right directional arrow) selects the next VT in a circular ring fashion
38 and Alt + <- (where "<-" represents the left directional arrow) changes
39 to the previous console in a circular fashion. The sequence Alt + ^
40 (where "^" represents the up directional arrow) is for the last used
41 console.
42
43 Virtual console switching can be done automatically (VT_AUTO) on receipt
44 of a "hot-key" or by the process owning the VT (VT_PROCESS). When
45 performed automatically, the process associated with the virtual console
46 is unaware of the switch. Saving and restoring the device are handled by
47 the underlying device driver and the virtual console manager. Note that
48 automatic switching is the default mode.
49
50 When a "hot-key" is sent when in process-controlled switch mode, the
51 process owning the VT is sent a signal (relsig) it has specified to the
52 virtual console manager (see signal(3C)) requesting the process to
53 release the physical device. At this point, the virtual console manager
54 awaits the VT_RELDISP ioctl from the process. If the process refuses to
55 release the device (meaning the switch does not occur), it performs a
56 VT_RELDISP ioctl with an argument of 0 (zero). If the process desires to
57 release the device, it saves the device state (keyboard, display, and I/O
58 registers) and then performs a VT_RELDISP with an argument of 1 to
59 complete the switch.
60
61 A ring of VT's can contain intermixed auto mode and process control mode
62 consoles. When an auto mode process becomes active, the underlying
63 device driver and the virtual console manager handle the restoring of the
64 device. Process control mode processes are sent a specified signal
65 (acqsig) when they become the active console. The process then restores
66 the device state (keyboard, display, and I/O registers) and performs
67 VT_RELDISP ioctl with an argument of VT_ACKACQ to complete the switching
68 protocol.
69
70 The modify-operations ioctls (VT_SETMODE, VT_RELDISP, VT_WAITACTIVE,
71 KDSETMODE) check if the VT is the controlling tty of the calling process.
72 If not, the sys_devices privilege is enforced. VT_ACTIVATE requires the
73 sys_devices privilege. Note that there is no controlling tty and
74 privilege check for query/view operations.
75
76 IOCTLS
77 The following ioctls apply to devices that support virtual consoles:
78
79 VT_ENABLED Queries to determine if VT functionality is available on the
80 system. The argument is a pointer to an integer. If VT
81 functionality is available, the integer is 1, otherwise it is
82 0.
83
84 VT_OPENQRY Finds an available VT. The argument is a pointer to an
85 integer. The integer is filled in with the number of the
86 first available console that no other process has open (and
87 hence, is available to be opened). If there are no available
88 VT's, -1 is filled in.
89
90 VT_GETMODE Determines the VT's current mode, either VT_AUTO or
91 VT_PROCESS. The argument is the address of the following
92 structure, as defined in <sys/vt.h>
93
94 struct vt_mode {
95 char mode; /* VT mode */
96 char waitv; /* not used */
97 short relsig; /* signal to use for release request */
98 short acqsig; /* signal to use for display acquired */
99 short frsig; /* not used */
100 }
101
102 /* Virtual console Modes */
103 #define VT_AUTO 0 /* automatic VT switching */
104 #define VT_PROCESS 1 /* process controls switching */
105
106 The structure will be filled in with the current value for
107 each field.
108
109 VT_SETMODE Sets the VT mode. The argument is a pointer to a vt_mode
110 structure as defined above. The structure should be filled
111 in with the desired mode. If process-control mode is
112 specified, the signals used to communicate with the process
113 should be specified. If any signals are not specified (value
114 is zero), the signal default is SIGUSR1 (for relsig and
115 acqsig).
116
117 VT_RELDISP Tells the VT manager if the process releases (or refuses to
118 release) the display. An argument of 1 indicates the VT is
119 released. An argument of 0 indicates refusal to release.
120 The VT_ACKACQ argument indicates if acquisition of the VT has
121 been completed.
122
123 VT_ACTIVATE
124 Makes the VT specified in the argument the active VT (in the
125 same manner as if a hotkey initiated the switch). If the
126 specified VT is not open or does not exist, the call fails
127 and errno is set to ENXIO.
128
129 VT_WAITACTIVE
130 If the specified VT is currently active, this call returns
131 immediately. Otherwise, it sleeps until the specified VT
132 becomes active, at which point it returns.
133
134 VT_GETSTATE
135 Obtains the active VT number and a list of open VTs. The
136 argument is an address to the following structure:
137
138 struct vt_stat {
139 unsigned short v_active, /* number of the active VT */
140 v_signal, /* not used */
141 /*
142 * count of open VTs. For every 1 in this
143 * field, there is an open VT
144 */
145 v_state;
146 }
147
148 With VT_GETSTATE, the VT manager first gets the number of the
149 active VT, then determines the number of open VTs in the
150 system and sets a 1 for each open VT in v_state. Next, the
151 VT manager transfers the information in structure vt_stat
152 passed by the user process.
153
154 KDGETMODE Obtains the text/graphics mode associated with the VT.
155
156 #define KD_TEXT 0
157 #define KD_GRAPHICS 1
158
159 KDSETMODE Sets the text/graphics mode to the VT.
160
161 KD_TEXT indicates that console text is displayed on the screen.
162 Normally KD_TEXT is combined with VT_AUTO mode for text
163 console terminals, so that the console text display
164 automatically is saved and restored on the hot key screen
165 switches.
166
167 KD_GRAPHICS indicates that the user/application (usually
168 Xserver) has direct control of the display for this VT in
169 graphics mode. Normally KD_GRAPHICS is combined with
170 VT_PROCESS mode for this VT indicating direct control of the
171 display in graphics mode. In this mode, all writes to the VT
172 using the write system call are ignored, and you must save
173 and restore the display on the hot key screen switches.
174
175 When the mode of the active VT is changed from KD_TEXT to
176 KD_GRAPHICS or a VT of KD_GRAPHICS mode is made active from a
177 previous active VT of KD_TEXT mode, the virtual console
178 manager initiates a KDSETMODE ioctl with KD_GRAPHICS as the
179 argument to the underlying console frame buffer device
180 indicating that current display is running into graphics
181 mode.
182
183 When the mode of the active VT is changed from KD_GRAPHICS to
184 KD_TEXT or a VT of KD_TEXT mode is actived from a previous
185 active VT of KD_GRAPHICS mode, the virtual console manager
186 initiates a KDSETMODE ioctl with KD_TEXT as the argument to
187 the underlying console frame buffer device indicating that
188 current display is running into console text mode.
189
190 FILES
191 /dev/vt/# VT devices.
192
193 SEE ALSO
194 ioctl(2), signal(3C), wscons(7D)
195
196 NOTES
197 By default, there are only five virtual console instance login prompts
198 running on /dev/vt/# (where "#" represents 2 to 6) in addition to the
199 system console running on /dev/console. Normally Xorg uses the seventh
200 virtual console (/dev/vt/7). To switch from consoles to Xserver (which
201 normally picks up the first available virtual console), use [ Ctrl + ]
202 Alt + F7 .
203
204 # svcs | grep login
205 online 17:49:11 svc:/system/console-login:default
206 online 17:49:11 svc:/system/console-login:vt2
207 online 17:49:11 svc:/system/console-login:vt3
208 online 17:49:11 svc:/system/console-login:vt4
209 online 17:49:11 svc:/system/console-login:vt5
210 online 17:49:11 svc:/system/console-login:vt6
211
212 console-login:default is for the system console, others for virtual
213 consoles.
214
215 You can modify properties/disable/enable and remove/add virtual consoles
216 using smf(5):
217
218 # svccfg -s console-login add vt8
219 # svccfg -s console-login:vt8 setprop \
220 ttymon/device=astring: "/dev/vt/8"
221 # svcadm enable console-login:vt8
222
223 illumos October 29, 2017 illumos