1 /*- 2 * Copyright 2015 Toomas Soome <tsoome@me.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * Chain loader to load BIOS boot block either from MBR or PBR. 29 * 30 * Note the boot block location 0000:7c000 conflicts with loader, so we need to 31 * read in to temporary space and relocate on exec, when btx is stopped. 32 */ 33 34 #include <sys/cdefs.h> 35 #include <stand.h> 36 #include <sys/param.h> 37 #include <sys/linker.h> 38 #include <sys/diskmbr.h> 39 40 #include "bootstrap.h" 41 #include "libi386/libi386.h" 42 #include "btxv86.h" 43 44 #ifdef LOADER_VERIEXEC_VECTX 45 #define VECTX_HANDLE(x) vctx 46 #else 47 #define VECTX_HANDLE(x) x 48 #endif 49 50 /* 51 * The MBR/VBR is located in first sector of disk/partition. 52 * Read 512B to temporary location and set up relocation. Then 53 * exec relocator. 54 */ 55 #define SECTOR_SIZE (512) 56 57 COMMAND_SET(chain, "chain", "chain load boot block from device", command_chain); 58 59 static int 60 command_chain(int argc, char *argv[]) 61 { 62 int fd, len, size = SECTOR_SIZE; 63 struct stat st; 64 vm_offset_t mem = 0x100000; 65 struct i386_devdesc *rootdev; 66 #ifdef LOADER_VERIEXEC_VECTX 67 struct vectx *vctx; 68 int verror; 69 #endif 70 71 if (argc == 1) { 72 command_errmsg = "no device or file name specified"; 73 return (CMD_ERROR); 74 } 75 if (argc != 2) { 76 command_errmsg = "invalid trailing arguments"; 77 return (CMD_ERROR); 78 } 79 80 fd = open(argv[1], O_RDONLY); 81 if (fd == -1) { 82 command_errmsg = "open failed"; 83 return (CMD_ERROR); 84 } 85 86 #ifdef LOADER_VERIEXEC_VECTX 87 vctx = vectx_open(fd, argv[1], 0L, NULL, &verror, __func__); 88 if (verror) { 89 sprintf(command_errbuf, "can't verify: %s", argv[1]); 90 close(fd); 91 free(vctx); 92 return (CMD_ERROR); 93 } 94 #else 95 #ifdef LOADER_VERIEXEC 96 if (verify_file(fd, argv[1], 0, VE_MUST, __func__) < 0) { 97 sprintf(command_errbuf, "can't verify: %s", argv[1]); 98 close(fd); 99 return (CMD_ERROR); 100 } 101 #endif 102 #endif 103 len = strlen(argv[1]); 104 if (argv[1][len-1] != ':') { 105 if (fstat(fd, &st) == -1) { 106 command_errmsg = "stat failed"; 107 close(fd); 108 return (CMD_ERROR); 109 } 110 size = st.st_size; 111 } else if (strncmp(argv[1], "disk", 4) != 0) { 112 command_errmsg = "can only use disk device"; 113 close(fd); 114 return (CMD_ERROR); 115 } 116 117 i386_getdev((void **)(&rootdev), argv[1], NULL); 118 if (rootdev == NULL) { 119 command_errmsg = "can't determine root device"; 120 close(fd); 121 return (CMD_ERROR); 122 } 123 124 if (archsw.arch_readin(VECTX_HANDLE(fd), mem, size) != size) { 125 command_errmsg = "failed to read disk"; 126 close(fd); 127 return (CMD_ERROR); 128 } 129 close(fd); 130 #ifdef LOADER_VERIEXEC_VECTX 131 verror = vectx_close(vctx, VE_MUST, __func__); 132 if (verror) { 133 free(vctx); 134 return (CMD_ERROR); 135 } 136 #endif 137 if (argv[1][len-1] == ':' && 138 *((uint16_t *)PTOV(mem + DOSMAGICOFFSET)) != DOSMAGIC) { 139 command_errmsg = "wrong magic"; 140 return (CMD_ERROR); 141 } 142 143 relocater_data[0].src = mem; 144 relocater_data[0].dest = 0x7C00; 145 relocater_data[0].size = size; 146 147 relocator_edx = bd_unit2bios(rootdev); 148 relocator_esi = relocater_size; 149 relocator_ds = 0; 150 relocator_es = 0; 151 relocator_fs = 0; 152 relocator_gs = 0; 153 relocator_ss = 0; 154 relocator_cs = 0; 155 relocator_sp = 0x7C00; 156 relocator_ip = 0x7C00; 157 relocator_a20_enabled = 0; 158 159 i386_copyin(relocater, 0x600, relocater_size); 160 161 dev_cleanup(); 162 163 __exec((void *)0x600); 164 165 panic("exec returned"); 166 return (CMD_ERROR); /* not reached */ 167 } 168