1 /* $NetBSD: prom.c,v 1.16 2018/09/03 16:29:22 riastradh Exp $ */
2
3 /*
4 * Mach Operating System
5 * Copyright (c) 1992 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie Mellon
26 * the rights to redistribute these changes.
27 */
28
29 #include <lib/libkern/libkern.h>
30
31 #include <sys/types.h>
32
33 #include <machine/prom.h>
34 #include <machine/rpb.h>
35
36 #include "common.h"
37
38 int console;
39
40 #if !defined(NO_GETCHAR) || !defined(NO_PUTCHAR_HALT)
41 static int test_getchar(int *);
42 #endif
43 static void putonechar(int c);
44
45 void
init_prom_calls(void)46 init_prom_calls(void)
47 {
48 extern struct prom_vec prom_dispatch_v;
49 struct rpb *r;
50 struct crb *c;
51 char buf[4];
52
53 r = (struct rpb *)HWRPB_ADDR;
54 c = (struct crb *)((u_int8_t *)r + r->rpb_crb_off);
55
56 prom_dispatch_v.routine_arg = c->crb_v_dispatch;
57 prom_dispatch_v.routine = c->crb_v_dispatch->entry_va;
58
59 /* Look for console tty. */
60 prom_getenv(PROM_E_TTY_DEV, buf, sizeof(buf));
61 console = buf[0] - '0';
62 }
63
64 #if !defined(NO_GETCHAR) || !defined(NO_PUTCHAR_HALT)
65 static int
test_getchar(int * xc)66 test_getchar(int *xc)
67 {
68 prom_return_t ret;
69
70 ret.bits = prom_dispatch(PROM_R_GETC, console);
71 *xc = ret.u.retval;
72 return ret.u.status == 0 || ret.u.status == 1;
73 }
74 #endif
75
76 #if !defined(NO_GETCHAR)
77 int
getchar(void)78 getchar(void)
79 {
80 int c;
81
82 for (;;) {
83 if (test_getchar(&c)) {
84 if (c == 3)
85 halt();
86 return c;
87 }
88 }
89 }
90 #endif
91
92 static void
putonechar(int c)93 putonechar(int c)
94 {
95 prom_return_t ret;
96 char cbuf = c;
97
98 do {
99 ret.bits = prom_dispatch(PROM_R_PUTS, console, &cbuf, 1);
100 } while ((ret.u.retval & 1) == 0);
101 }
102
103 void
putchar(int c)104 putchar(int c)
105 {
106 #if !defined(NO_PUTCHAR_HALT)
107 int typed_c;
108 #endif
109
110 if (c == '\r' || c == '\n') {
111 putonechar('\r');
112 c = '\n';
113 }
114 putonechar(c);
115 #if !defined(NO_PUTCHAR_HALT)
116 if (test_getchar(&typed_c))
117 if (typed_c == 3)
118 halt();
119 #endif
120 }
121
122 int
prom_getenv(int id,char * buf,int len)123 prom_getenv(int id, char *buf, int len)
124 {
125 /*
126 * On at least some systems, the GETENV call requires a
127 * 8-byte-aligned buffer, or it bails out with a "kernel stack
128 * not valid halt". Provide a local, aligned buffer here and
129 * then copy to the caller's buffer.
130 */
131 static char abuf[128] __attribute__((aligned (8)));
132 prom_return_t ret;
133
134 ret.bits = prom_dispatch(PROM_R_GETENV, id, abuf, 128);
135 if (ret.u.status & 0x4)
136 ret.u.retval = 0;
137 len = uimin(len - 1, ret.u.retval);
138 memcpy(buf, abuf, len);
139 buf[len] = '\0';
140
141 return (len);
142 }
143