1 /* $OpenBSD: pmon.c,v 1.4 2010/02/16 21:29:54 miod Exp $ */
2
3 /*
4 * Copyright (c) 2009 Miodrag Vallat.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/param.h>
20 #include <sys/systm.h>
21 #include <sys/cpu.h>
22 #include <sys/proc.h>
23
24 #include <mips/cpuregs.h>
25 #include <mips/pmon/pmon.h>
26
27 int pmon_argc;
28 int32_t *pmon_argv;
29 int32_t *pmon_envp;
30
31 void
pmon_init(int32_t argc,int32_t argv,int32_t envp,int32_t callvec)32 pmon_init(int32_t argc, int32_t argv, int32_t envp, int32_t callvec)
33 {
34 pmon_callvec = callvec;
35
36 pmon_argc = argc;
37 /* sign extend pointers */
38 pmon_argv = (int32_t *)(vaddr_t)argv;
39 pmon_envp = (int32_t *)(vaddr_t)envp;
40 }
41
42 const char *
pmon_getarg(const int argno)43 pmon_getarg(const int argno)
44 {
45 if (argno < 0 || argno >= pmon_argc)
46 return NULL;
47
48 return (const char *)(vaddr_t)pmon_argv[argno];
49 }
50
51 const char *
pmon_getenv(const char * var)52 pmon_getenv(const char *var)
53 {
54 int32_t *envptr = pmon_envp;
55 const char *envstr;
56 size_t varlen;
57
58 if (envptr == NULL)
59 return NULL;
60
61 varlen = strlen(var);
62 while (*envptr != 0) {
63 envstr = (const char *)(vaddr_t)*envptr;
64 /*
65 * There is a PMON2000 bug, at least on Lemote Yeeloong,
66 * which causes it to override part of the environment
67 * pointers array with the environment data itself.
68 *
69 * This only happens on cold boot, and if the BSD kernel
70 * is loaded without symbols (i.e. no option -k passed
71 * to the boot command).
72 *
73 * Until a suitable workaround is found or the bug is
74 * fixed, ignore broken environment information and
75 * tell the user (in case this prevents us from finding
76 * important information).
77 */
78 if ((vaddr_t)envstr < (vaddr_t)MIPS_KSEG1_START ||
79 (vaddr_t)envstr >= (vaddr_t)MIPS_KSEG2_START) {
80 printf("WARNING! CORRUPTED ENVIRONMENT!\n");
81 printf("Unable to search for %s.\n", var);
82 #ifdef _STANDALONE
83 printf("If boot fails, power-cycle the machine.\n");
84 #else
85 printf("If the kernel fails to identify the system"
86 " type, please boot it again with `-k' option.\n");
87 #endif
88
89 /* terminate environment for further calls */
90 *envptr = 0;
91 break;
92 }
93 if (strncmp(envstr, var, varlen) == 0 &&
94 envstr[varlen] == '=')
95 return envstr + varlen + 1;
96 envptr++;
97 }
98
99 return NULL;
100 }
101