freebsd-dev/sys/boot/i386/libi386/startprog.S
Mike Smith c2f9d95de5 This is the new unified bootstrap, sometimes known previously as the
'three-stage' bootstrap.
There are a number of caveats with the code in its current state:
 - The i386 bootstrap only supports booting from a floppy.
 - The kernel and kld do not yet know how to deal with the extended
   information and module summary passed in.
 - PnP-based autodetection and demand loading of modules is not implemented.
 - i386 ELF kernel loading is not ready yet.
 - The i386 bootstrap is loaded via an ugly blockmap.

On the alpha, both net- and disk-booting (SRM console machines only) is
supported.  No blockmaps are used by this code.

Obtained from:	Parts from the NetBSD/i386 standalone bootstrap.
1998-08-21 03:17:42 +00:00

121 lines
3.4 KiB
ArmAsm

/* $NetBSD: startprog.S,v 1.1.1.1 1997/03/14 02:40:33 perry Exp $ */
/* starts program in protected mode / flat space
with given stackframe
needs global variables flatcodeseg and flatdataseg
(gdt offsets)
derivied from: NetBSD:sys/arch/i386/boot/asm.S
*/
/*
* Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
*
* Mach Operating System
* Copyright (c) 1992, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
Copyright 1988, 1989, 1990, 1991, 1992
by Intel Corporation, Santa Clara, California.
All Rights Reserved
Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appears in all
copies and that both the copyright notice and this permission notice
appear in supporting documentation, and that the name of Intel
not be used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.
INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <machine/asm.h>
/*
* startprog(phyaddr,argc,argv,stack)
* start the program on protected mode where phyaddr is the entry point
*/
ENTRY(startprog)
pushl %ebp
movl %esp, %ebp
# prepare a new stack
movl $flatdataseg, %ebx
movw %bx, %es # for arg copy
movl 20(%ebp), %eax # stack
subl $4,%eax
movl %eax, %edi
# push some number of args onto the stack
movl 12(%ebp), %ecx # argc
movl %ecx, %eax
decl %eax
shl $2, %eax
addl 16(%ebp), %eax # ptr to last arg
movl %eax, %esi
std # backwards
rep
movsl
cld # LynxOS depends on it
movl 8(%ebp), %ecx # entry
# set new stackptr (movsl decd sp 1 more -> dummy return address)
movw %bx, %ss
movl %edi, %esp
# plug in a return address so that FreeBSD detects we are using
# bootinfo
movl $ourreturn, %eax
movl %eax, (%esp)
# push on our entry address
movl $flatcodeseg, %ebx # segment
pushl %ebx
pushl %ecx #entry
# convert over the other data segs
movl $flatdataseg, %ebx
movl %bx, %ds
movl %bx, %es
# convert the PC (and code seg)
lret
ourreturn:
/* For now there is not much we can do, just lock in a loop */
jmp ourreturn