1 /* 2 * This file and its contents are supplied under the terms of the 3 * Common Development and Distribution License ("CDDL"), version 1.0. 4 * You may only use this file in accordance with the terms of version 5 * 1.0 of the CDDL. 6 * 7 * A full copy of the text of the CDDL should have accompanied this 8 * source. A copy of the CDDL is also available via the Internet at 9 * http://www.illumos.org/license/CDDL. 10 */ 11 12 /* 13 * Copyright 2015 Toomas Soome <tsoome@me.com> 14 */ 15 16 /* 17 * Chain loader to load BIOS boot block either from MBR or PBR. 18 * 19 * Note the boot block location 0000:7c000 conflicts with loader, so we need to 20 * read in to temporary space and relocate on exec, when btx is stopped. 21 */ 22 23 #include <sys/cdefs.h> 24 #include <stand.h> 25 #include <sys/param.h> 26 #include <sys/linker.h> 27 #include <sys/diskmbr.h> 28 29 #include "bootstrap.h" 30 #include "libi386/libi386.h" 31 #include "btxv86.h" 32 33 /* 34 * The MBR/VBR is located in first sector of disk/partition. 35 * Read 512B to temporary location and set up relocation. Then 36 * exec relocator. 37 */ 38 #define SECTOR_SIZE (512) 39 40 COMMAND_SET(chain, "chain", "chain load boot block from device", command_chain); 41 42 static int 43 command_chain(int argc, char *argv[]) 44 { 45 int fd, len, size = SECTOR_SIZE; 46 struct stat st; 47 vm_offset_t mem = 0x100000; 48 struct i386_devdesc *rootdev; 49 50 if (argc == 1) { 51 command_errmsg = "no device or file name specified"; 52 return (CMD_ERROR); 53 } 54 if (argc != 2) { 55 command_errmsg = "invalid trailing arguments"; 56 return (CMD_ERROR); 57 } 58 59 fd = open(argv[1], O_RDONLY); 60 if (fd == -1) { 61 command_errmsg = "open failed"; 62 return (CMD_ERROR); 63 } 64 65 len = strlen(argv[1]); 66 if (argv[1][len-1] != ':') { 67 if (fstat(fd, &st) == -1) { 68 command_errmsg = "stat failed"; 69 close(fd); 70 return (CMD_ERROR); 71 } 72 size = st.st_size; 73 } else if (strncmp(argv[1], "disk", 4) != 0) { 74 command_errmsg = "can only use disk device"; 75 close(fd); 76 return (CMD_ERROR); 77 } 78 79 i386_getdev((void **)(&rootdev), argv[1], NULL); 80 if (rootdev == NULL) { 81 command_errmsg = "can't determine root device"; 82 close(fd); 83 return (CMD_ERROR); 84 } 85 86 if (archsw.arch_readin(fd, mem, size) != size) { 87 command_errmsg = "failed to read disk"; 88 close(fd); 89 return (CMD_ERROR); 90 } 91 close(fd); 92 93 if (argv[1][len-1] == ':' && 94 *((uint16_t *)PTOV(mem + DOSMAGICOFFSET)) != DOSMAGIC) { 95 command_errmsg = "wrong magic"; 96 return (CMD_ERROR); 97 } 98 99 relocater_data[0].src = mem; 100 relocater_data[0].dest = 0x7C00; 101 relocater_data[0].size = size; 102 103 relocator_edx = bd_unit2bios(rootdev->d_unit); 104 relocator_esi = relocater_size; 105 relocator_ds = 0; 106 relocator_es = 0; 107 relocator_fs = 0; 108 relocator_gs = 0; 109 relocator_ss = 0; 110 relocator_cs = 0; 111 relocator_sp = 0x7C00; 112 relocator_ip = 0x7C00; 113 relocator_a20_enabled = 0; 114 115 i386_copyin(relocater, 0x600, relocater_size); 116 117 dev_cleanup(); 118 119 __exec((void *)0x600); 120 121 panic("exec returned"); 122 return (CMD_ERROR); /* not reached */ 123 } 124