freebsd-dev/sys/i386/boot/dosboot/exec.h

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This is a MS-DOS program, but is does something useful for us: It boots FreeBSD from a running MS-DOS system. It's compiled using some MS-DOS tools, but there is a binary hidden in the uuencoded file. (Go ahead, flame me if you can come up with a solution for the problem. Just saying "this is bad" doesn't count!) Rod, you were right: one would have to deal with weird interfaces to the memory managers, and it seems that Christian found them all, and made them work. Thanks Christian! Reviewed by: phk Submitted by: DI. Christian Gusenbauer <cg@fimp01.fim.uni-linz.ac.at> Christians README: ------------------ Hi Everybody! This is version 1.5 of "fbsdboot", a program that allows you to boot a kernel from a MS-DOS partition or a FreeBSD partition. This program runs using DOS. It works with various memory managers (like EMM386, 386MAX) under certain circumstances. First, a FreeBSD kernel is always loaded to memory starting at 0x100000. To assure that loading the kernel *does not* overwrite memory used by memory managers, high memory for the kernel is allocated and after loading the kernel it's moved to 0x100000. Second, there are many ways to switch to protected mode which is necessary to start the kernel. Each BIOS gives you the possibility to use INT15H (AH=89H) to do that. But some memory-managers like 386max does not allow you to use this method. An other way to do the switch is to use DPMI services, but they do not guarantee, that the protected mode application is executed with privilege level 0. Therefore this method is *not* used. VCPI services offer another way to switch to protected mode, and VCPI servers are built into "emm386.exe", "386max" and "qemm". That's why, this method is implemented in fbsdboot.exe. Fbsdboot.exe tries to switch to protected mode using VCPI services. If they're not available INT15H is used to do the switch. If that fails, it's not possible for this version of fbsdboot.exe to boot a kernel :-(. You can get commandline options of fbsdboot if you start it with "-?" as option! I don't know, if fbsdboot works with QEMM, as I don't have the possibility to test it. Enjoy and have fun! Christian. cg@fimp01.fim.uni-linz.ac.at PS: Many thanks to Bruce Evans for his assistance!
1995-02-15 04:45:50 +00:00
/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)exec.h 8.3 (Berkeley) 1/21/94
* $Id$
This is a MS-DOS program, but is does something useful for us: It boots FreeBSD from a running MS-DOS system. It's compiled using some MS-DOS tools, but there is a binary hidden in the uuencoded file. (Go ahead, flame me if you can come up with a solution for the problem. Just saying "this is bad" doesn't count!) Rod, you were right: one would have to deal with weird interfaces to the memory managers, and it seems that Christian found them all, and made them work. Thanks Christian! Reviewed by: phk Submitted by: DI. Christian Gusenbauer <cg@fimp01.fim.uni-linz.ac.at> Christians README: ------------------ Hi Everybody! This is version 1.5 of "fbsdboot", a program that allows you to boot a kernel from a MS-DOS partition or a FreeBSD partition. This program runs using DOS. It works with various memory managers (like EMM386, 386MAX) under certain circumstances. First, a FreeBSD kernel is always loaded to memory starting at 0x100000. To assure that loading the kernel *does not* overwrite memory used by memory managers, high memory for the kernel is allocated and after loading the kernel it's moved to 0x100000. Second, there are many ways to switch to protected mode which is necessary to start the kernel. Each BIOS gives you the possibility to use INT15H (AH=89H) to do that. But some memory-managers like 386max does not allow you to use this method. An other way to do the switch is to use DPMI services, but they do not guarantee, that the protected mode application is executed with privilege level 0. Therefore this method is *not* used. VCPI services offer another way to switch to protected mode, and VCPI servers are built into "emm386.exe", "386max" and "qemm". That's why, this method is implemented in fbsdboot.exe. Fbsdboot.exe tries to switch to protected mode using VCPI services. If they're not available INT15H is used to do the switch. If that fails, it's not possible for this version of fbsdboot.exe to boot a kernel :-(. You can get commandline options of fbsdboot if you start it with "-?" as option! I don't know, if fbsdboot works with QEMM, as I don't have the possibility to test it. Enjoy and have fun! Christian. cg@fimp01.fim.uni-linz.ac.at PS: Many thanks to Bruce Evans for his assistance!
1995-02-15 04:45:50 +00:00
*/
#ifndef _SYS_EXEC_H_
#define _SYS_EXEC_H_
/*
* The following structure is found at the top of the user stack of each
* user process. The ps program uses it to locate argv and environment
* strings. Programs that wish ps to display other information may modify
* it; normally ps_argvstr points to the text for argv[0], and ps_nargvstr
* is the same as the program's argc. The fields ps_envstr and ps_nenvstr
* are the equivalent for the environment.
*/
struct ps_strings {
char *ps_argvstr; /* first of 0 or more argument strings */
long ps_nargvstr; /* the number of argument strings */
char *ps_envstr; /* first of 0 or more environment strings */
long ps_nenvstr; /* the number of environment strings */
};
/*
* Address of ps_strings structure (in user space).
*/
#define SPARE_USRSPACE 256
#define PS_STRINGS ((struct ps_strings *) \
(USRSTACK - sizeof(struct ps_strings) - SPARE_USRSPACE))
/*
* Arguments to the exec system call.
*/
struct execve_args {
char *fname;
char **argv;
char **envv;
};
struct execsw {
int (*ex_imgact)(void * /* struct image_params * */);
const char *ex_name;
};
#ifdef KERNEL
extern const struct execsw **execsw;
#endif
#include "mexec.h"
#endif