freebsd-nq/sys/i386/boot/dosboot/bootinfo.h
Poul-Henning Kamp b8e4cd2bb3 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

51 lines
2.2 KiB
C

/*-
* Copyright (C) 1994 by Rodney W. Grimes, Milwaukie, Oregon 97222
* All rights reserved.
*
* 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 as
* the first lines of this file unmodified.
* 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 Rodney W. Grimes.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RODNEY W. GRIMES ``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 RODNEY W. GRIMES 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.
*
* $Id: bootinfo.h,v 1.3 1994/11/18 05:26:52 phk Exp $
*/
#ifndef _MACHINE_BOOTINFO_H_
#define _MACHINE_BOOTINFO_H_
#define N_BIOS_GEOM 8
struct bootinfo_t {
unsigned long version;
unsigned char *kernelname;
void *nfs_diskless;
unsigned long n_bios_used;
unsigned long bios_geom[N_BIOS_GEOM];
};
#ifdef KERNEL
extern struct bootinfo_t bootinfo;
#endif
#endif /* _MACHINE_BOOTINFO_H_ */