2 * Copyright 2015 Toomas Soome <tsoome@me.com>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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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
28 * Chain loader to load BIOS boot block either from MBR or PBR.
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.
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
38 #include <sys/param.h>
39 #include <sys/linker.h>
40 #include <sys/diskmbr.h>
42 #include "bootstrap.h"
43 #include "libi386/libi386.h"
46 #ifdef LOADER_VERIEXEC_VECTX
47 #define VECTX_HANDLE(x) vctx
49 #define VECTX_HANDLE(x) x
53 * The MBR/VBR is located in first sector of disk/partition.
54 * Read 512B to temporary location and set up relocation. Then
57 #define SECTOR_SIZE (512)
59 COMMAND_SET(chain, "chain", "chain load boot block from device", command_chain);
62 command_chain(int argc, char *argv[])
64 int fd, len, size = SECTOR_SIZE;
66 vm_offset_t mem = 0x100000;
67 struct i386_devdesc *rootdev;
68 #ifdef LOADER_VERIEXEC_VECTX
74 command_errmsg = "no device or file name specified";
78 command_errmsg = "invalid trailing arguments";
82 fd = open(argv[1], O_RDONLY);
84 command_errmsg = "open failed";
88 #ifdef LOADER_VERIEXEC_VECTX
89 vctx = vectx_open(fd, argv[1], 0L, NULL, &verror, __func__);
91 sprintf(command_errbuf, "can't verify: %s", argv[1]);
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]);
105 len = strlen(argv[1]);
106 if (argv[1][len-1] != ':') {
107 if (fstat(fd, &st) == -1) {
108 command_errmsg = "stat failed";
113 } else if (strncmp(argv[1], "disk", 4) != 0) {
114 command_errmsg = "can only use disk device";
119 i386_getdev((void **)(&rootdev), argv[1], NULL);
120 if (rootdev == NULL) {
121 command_errmsg = "can't determine root device";
126 if (archsw.arch_readin(VECTX_HANDLE(fd), mem, size) != size) {
127 command_errmsg = "failed to read disk";
132 #ifdef LOADER_VERIEXEC_VECTX
133 verror = vectx_close(vctx, VE_MUST, __func__);
139 if (argv[1][len-1] == ':' &&
140 *((uint16_t *)PTOV(mem + DOSMAGICOFFSET)) != DOSMAGIC) {
141 command_errmsg = "wrong magic";
145 relocater_data[0].src = mem;
146 relocater_data[0].dest = 0x7C00;
147 relocater_data[0].size = size;
149 relocator_edx = bd_unit2bios(rootdev);
150 relocator_esi = relocater_size;
157 relocator_sp = 0x7C00;
158 relocator_ip = 0x7C00;
159 relocator_a20_enabled = 0;
161 i386_copyin(relocater, 0x600, relocater_size);
165 __exec((void *)0x600);
167 panic("exec returned");
168 return (CMD_ERROR); /* not reached */