1 /*
2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
3 */
4 /*
5 * Copyright (c) 1987, 1988 NeXT, Inc.
6 *
7 * HISTORY 7-Jan-93 Mac Gillon (mgillon) at NeXT Integrated POSIX support
8 *
9 * 12-Aug-87 John Seamons (jks) at NeXT Ported to NeXT.
10 */
11
12 /*
13 * Indirect driver for console.
14 */
15 #include <sys/param.h>
16 #include <sys/systm.h>
17 #include <sys/conf.h>
18 #include <sys/ioctl.h>
19 #include <sys/tty.h>
20 #include <sys/proc.h>
21 #include <sys/uio.h>
22
23 struct tty *constty; /* current console device */
24
25 /*
26 * The km driver supplied the default console device for the systems
27 * (usually a raw frame buffer driver, but potentially a serial driver).
28 */
29 extern struct tty *km_tty[1];
30
31 /*
32 * cdevsw[] entries for the console device driver
33 */
34 int cnopen(__unused dev_t dev, int flag, int devtype, proc_t pp);
35 int cnclose(__unused dev_t dev, int flag, int mode, proc_t pp);
36 int cnread(__unused dev_t dev, struct uio *uio, int ioflag);
37 int cnwrite(__unused dev_t dev, struct uio *uio, int ioflag);
38 int cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flg, proc_t p);
39 int cnselect(__unused dev_t dev, int flag, void * wql, proc_t p);
40
41 static dev_t
cndev(void)42 cndev(void)
43 {
44 if (constty) {
45 return constty->t_dev;
46 } else {
47 return km_tty[0]->t_dev;
48 }
49 }
50
51 int
cnopen(__unused dev_t dev,int flag,int devtype,struct proc * pp)52 cnopen(__unused dev_t dev, int flag, int devtype, struct proc *pp)
53 {
54 dev = cndev();
55 return (*cdevsw[major(dev)].d_open)(dev, flag, devtype, pp);
56 }
57
58
59 int
cnclose(__unused dev_t dev,int flag,int mode,struct proc * pp)60 cnclose(__unused dev_t dev, int flag, int mode, struct proc *pp)
61 {
62 dev = cndev();
63 return (*cdevsw[major(dev)].d_close)(dev, flag, mode, pp);
64 }
65
66
67 int
cnread(__unused dev_t dev,struct uio * uio,int ioflag)68 cnread(__unused dev_t dev, struct uio *uio, int ioflag)
69 {
70 dev = cndev();
71 return (*cdevsw[major(dev)].d_read)(dev, uio, ioflag);
72 }
73
74
75 int
cnwrite(__unused dev_t dev,struct uio * uio,int ioflag)76 cnwrite(__unused dev_t dev, struct uio *uio, int ioflag)
77 {
78 dev = cndev();
79 return (*cdevsw[major(dev)].d_write)(dev, uio, ioflag);
80 }
81
82
83 int
cnioctl(__unused dev_t dev,u_long cmd,caddr_t addr,int flag,struct proc * p)84 cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
85 {
86 dev = cndev();
87
88 /*
89 * XXX This check prevents the cons.c code from being shared between
90 * XXX all architectures; it is probably not needed on ARM, either,
91 * XXX but I have no test platforms or ability to run a kernel.
92 *
93 * Superuser can always use this to wrest control of console
94 * output from the "virtual" console.
95 */
96 if ((unsigned) cmd == TIOCCONS && constty) {
97 int error = proc_suser(p);
98 if (error) {
99 return error;
100 }
101 constty = NULL;
102 return 0;
103 }
104 return (*cdevsw[major(dev)].d_ioctl)(dev, cmd, addr, flag, p);
105 }
106
107
108 int
cnselect(__unused dev_t dev,int flag,void * wql,struct proc * p)109 cnselect(__unused dev_t dev, int flag, void *wql, struct proc *p)
110 {
111 dev = cndev();
112 return (*cdevsw[major(dev)].d_select)(dev, flag, wql, p);
113 }
114