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 __FBSDID("$FreeBSD$"); 36 37 #include <stand.h> 38 #include <sys/param.h> 39 #include <sys/linker.h> 40 #include <sys/diskmbr.h> 41 42 #include "bootstrap.h" 43 #include "libi386/libi386.h" 44 #include "btxv86.h" 45 46 #ifdef LOADER_VERIEXEC_VECTX 47 #define VECTX_HANDLE(x) vctx 48 #else 49 #define VECTX_HANDLE(x) x 50 #endif 51 52 /* 53 * The MBR/VBR is located in first sector of disk/partition. 54 * Read 512B to temporary location and set up relocation. Then 55 * exec relocator. 56 */ 57 #define SECTOR_SIZE (512) 58 59 COMMAND_SET(chain, "chain", "chain load boot block from device", command_chain); 60 61 static int 62 command_chain(int argc, char *argv[]) 63 { 64 int fd, len, size = SECTOR_SIZE; 65 struct stat st; 66 vm_offset_t mem = 0x100000; 67 struct i386_devdesc *rootdev; 68 #ifdef LOADER_VERIEXEC_VECTX 69 struct vectx *vctx; 70 int verror; 71 #endif 72 73 if (argc == 1) { 74 command_errmsg = "no device or file name specified"; 75 return (CMD_ERROR); 76 } 77 if (argc != 2) { 78 command_errmsg = "invalid trailing arguments"; 79 return (CMD_ERROR); 80 } 81 82 fd = open(argv[1], O_RDONLY); 83 if (fd == -1) { 84 command_errmsg = "open failed"; 85 return (CMD_ERROR); 86 } 87 88 #ifdef LOADER_VERIEXEC_VECTX 89 vctx = vectx_open(fd, argv[1], 0L, NULL, &verror, __func__); 90 if (verror) { 91 sprintf(command_errbuf, "can't verify: %s", argv[1]); 92 close(fd); 93 free(vctx); 94 return (CMD_ERROR); 95 } 96 #else 97 #ifdef LOADER_VERIEXEC 98 if (verify_file(fd, argv[1], 0, VE_MUST, __func__) < 0) { 99 sprintf(command_errbuf, "can't verify: %s", argv[1]); 100 close(fd); 101 return (CMD_ERROR); 102 } 103 #endif 104 #endif 105 len = strlen(argv[1]); 106 if (argv[1][len-1] != ':') { 107 if (fstat(fd, &st) == -1) { 108 command_errmsg = "stat failed"; 109 close(fd); 110 return (CMD_ERROR); 111 } 112 size = st.st_size; 113 } else if (strncmp(argv[1], "disk", 4) != 0) { 114 command_errmsg = "can only use disk device"; 115 close(fd); 116 return (CMD_ERROR); 117 } 118 119 i386_getdev((void **)(&rootdev), argv[1], NULL); 120 if (rootdev == NULL) { 121 command_errmsg = "can't determine root device"; 122 close(fd); 123 return (CMD_ERROR); 124 } 125 126 if (archsw.arch_readin(VECTX_HANDLE(fd), mem, size) != size) { 127 command_errmsg = "failed to read disk"; 128 close(fd); 129 return (CMD_ERROR); 130 } 131 close(fd); 132 #ifdef LOADER_VERIEXEC_VECTX 133 verror = vectx_close(vctx, VE_MUST, __func__); 134 if (verror) { 135 free(vctx); 136 return (CMD_ERROR); 137 } 138 #endif 139 if (argv[1][len-1] == ':' && 140 *((uint16_t *)PTOV(mem + DOSMAGICOFFSET)) != DOSMAGIC) { 141 command_errmsg = "wrong magic"; 142 return (CMD_ERROR); 143 } 144 145 relocater_data[0].src = mem; 146 relocater_data[0].dest = 0x7C00; 147 relocater_data[0].size = size; 148 149 relocator_edx = bd_unit2bios(rootdev); 150 relocator_esi = relocater_size; 151 relocator_ds = 0; 152 relocator_es = 0; 153 relocator_fs = 0; 154 relocator_gs = 0; 155 relocator_ss = 0; 156 relocator_cs = 0; 157 relocator_sp = 0x7C00; 158 relocator_ip = 0x7C00; 159 relocator_a20_enabled = 0; 160 161 i386_copyin(relocater, 0x600, relocater_size); 162 163 dev_cleanup(); 164 165 __exec((void *)0x600); 166 167 panic("exec returned"); 168 return (CMD_ERROR); /* not reached */ 169 } 170