2 * Copyright (c) 1992, 1993, 1996
3 * Berkeley Software Design, Inc. All rights reserved.
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.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Berkeley Software
18 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
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23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * BSDI doscmd_loader.c,v 2.3 1996/04/08 19:32:33 bostic Exp
32 * $FreeBSD: src/usr.bin/doscmd/doscmd_loader.c,v 1.2.2.1 2002/04/25 11:04:51 tg Exp $
33 * $DragonFly: src/usr.bin/doscmd/doscmd_loader.c,v 1.4 2004/01/22 03:22:52 rob Exp $
41 * reserve space in "low" memory for the interrupt vector table
43 static const char filler[4096] = { 0, };
45 #define _PATH_DOS_KERNEL_DIR "/usr/libexec/"
46 #define _PATH_DOS_KERNEL "doscmd.kernel"
55 if ((fp = fopen(_PATH_DOS_KERNEL, "r")) == NULL &&
56 (fp = fopen("obj/" _PATH_DOS_KERNEL, "r")) == NULL &&
57 (fp = fopen(_PATH_DOS_KERNEL_DIR _PATH_DOS_KERNEL, "r")) == NULL &&
58 (fp = fopen(getenv("DOS_KERNEL"), "r")) == NULL)
59 err(1, "load_kernel");
61 if (fread(&exec, sizeof(exec), 1, fp) != 1 || N_GETMAGIC(exec) != OMAGIC)
62 errx(1, "bad kernel file format");
64 start_address = exec.a_entry & (~(getpagesize() - 1));
65 if (brk(start_address + exec.a_text + exec.a_data + exec.a_bss) < 0)
66 err(1, "load_kernel");
67 fread((char *)start_address, exec.a_text + exec.a_data, 1, fp);
68 bzero((char *)(start_address + exec.a_text + exec.a_data), exec.a_bss);
74 main(int argc, char **argv, char **environ)
76 void (*entry_point)();
78 int fd = open("/dev/mem", 0);
88 entry_point = (void (*)()) load_kernel();
91 if (read(fd, 0, 0x500 != 0x500))
97 (*entry_point)(argc, argv, environ);
98 errx(1, "return from doscmd kernel???");