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/proc.h> 22 23 #include <machine/cpu.h> 24 #include <mips/pmon/pmon.h> 25 26 int pmon_argc; 27 int32_t *pmon_argv; 28 int32_t *pmon_envp; 29 30 void 31 pmon_init(int32_t argc, int32_t argv, int32_t envp, int32_t callvec) 32 { 33 pmon_callvec = callvec; 34 35 pmon_argc = argc; 36 /* sign extend pointers */ 37 pmon_argv = (int32_t *)(vaddr_t)argv; 38 pmon_envp = (int32_t *)(vaddr_t)envp; 39 } 40 41 const char * 42 pmon_getarg(const int argno) 43 { 44 if (argno < 0 || argno >= pmon_argc) 45 return NULL; 46 47 return (const char *)(vaddr_t)pmon_argv[argno]; 48 } 49 50 const char * 51 pmon_getenv(const char *var) 52 { 53 int32_t *envptr = pmon_envp; 54 const char *envstr; 55 size_t varlen; 56 57 if (envptr == NULL) 58 return NULL; 59 60 varlen = strlen(var); 61 while (*envptr != 0) { 62 envstr = (const char *)(vaddr_t)*envptr; 63 /* 64 * There is a PMON2000 bug, at least on Lemote Yeeloong, 65 * which causes it to override part of the environment 66 * pointers array with the environment data itself. 67 * 68 * This only happens on cold boot, and if the BSD kernel 69 * is loaded without symbols (i.e. no option -k passed 70 * to the boot command). 71 * 72 * Until a suitable workaround is found or the bug is 73 * fixed, ignore broken environment information and 74 * tell the user (in case this prevents us from finding 75 * important information). 76 */ 77 if ((vaddr_t)envstr < (vaddr_t)MIPS_KSEG1_START || 78 (vaddr_t)envstr >= (vaddr_t)MIPS_KSEG2_START) { 79 printf("WARNING! CORRUPTED ENVIRONMENT!\n"); 80 printf("Unable to search for %s.\n", var); 81 #ifdef _STANDALONE 82 printf("If boot fails, power-cycle the machine.\n"); 83 #else 84 printf("If the kernel fails to identify the system" 85 " type, please boot it again with `-k' option.\n"); 86 #endif 87 88 /* terminate environment for further calls */ 89 *envptr = 0; 90 break; 91 } 92 if (strncmp(envstr, var, varlen) == 0 && 93 envstr[varlen] == '=') 94 return envstr + varlen + 1; 95 envptr++; 96 } 97 98 return NULL; 99 } 100