479 lines
10 KiB
ArmAsm
479 lines
10 KiB
ArmAsm
/*
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* Mach Operating System
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* Copyright (c) 1992, 1991 Carnegie Mellon University
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* All Rights Reserved.
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
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* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie Mellon
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* the rights to redistribute these changes.
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*
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* from: Mach, Revision 2.2 92/04/04 11:34:26 rpd
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* $FreeBSD$
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*/
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/*
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Copyright 1988, 1989, 1990, 1991, 1992
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by Intel Corporation, Santa Clara, California.
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All Rights Reserved
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Permission to use, copy, modify, and distribute this software and
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its documentation for any purpose and without fee is hereby
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granted, provided that the above copyright notice appears in all
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copies and that both the copyright notice and this permission notice
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appear in supporting documentation, and that the name of Intel
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not be used in advertising or publicity pertaining to distribution
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of the software without specific, written prior permission.
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INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
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INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
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IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
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CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
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NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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/*
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* Extensions for El Torito CD-ROM booting:
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*
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* Copyright <EFBFBD> 1997 Pluto Technologies International, Inc. Boulder CO
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* Copyright <EFBFBD> 1997 interface business GmbH, Dresden.
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* All rights reserved.
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*
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* This code has been written by J<EFBFBD>rg Wunsch, Dresden.
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* Direct comments to <joerg_wunsch@interface-business.de>.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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.file "bios.s"
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#include "asm.h"
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.text
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#ifndef CDBOOT
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/*
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* biosread(dev, cyl, head, sec, nsec, offset)
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* Read "nsec" sectors from disk to offset "offset" in boot segment
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* BIOS call "INT 0x13 Function 0x2" to read sectors from disk into memory
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* Call with %ah = 0x2
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* %al = number of sectors
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* %ch = cylinder
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* %cl = sector
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* %dh = head
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* %dl = drive (0x80 for hard disk, 0x0 for floppy disk)
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* %es:%bx = segment:offset of buffer
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* Return:
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* %al = 0x0 on success; err code on failure
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*/
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ENTRY(biosread)
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %esi
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push %edi
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movb 0x10(%ebp), %dh
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movw 0x0c(%ebp), %cx
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/* cylinder; the highest 2 bits of cyl is in %cl */
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xchgb %ch, %cl
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rorb $2, %cl
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movb 0x14(%ebp), %al
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orb %al, %cl
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incb %cl /* sector; sec starts from 1, not 0 */
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movb 0x8(%ebp), %dl /* device */
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movl 0x1c(%ebp), %ebx /* offset */
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/* prot_to_real will set %es to BOOTSEG */
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call EXT(prot_to_real) /* enter real mode */
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movb $0x2, %ah /* subfunction */
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addr32
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movb 0x18(%ebp), %al /* number of sectors */
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sti
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int $0x13
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cli
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/* save return value (actually movw %ax, %bx) */
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mov %eax, %ebx
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data32
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call EXT(real_to_prot) /* back to protected mode */
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xor %eax, %eax
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movb %bh, %al /* return value in %ax */
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pop %edi
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pop %esi
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pop %ebx
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pop %ebp
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ret
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#else /* CDBOOT */
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/*
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* int
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* getbootspec(struct specpacket *offset)
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*
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* Read CD-ROM boot specification packet to "offset".
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*/
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ENTRY(getbootspec)
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push %ebp
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mov %esp, %ebp
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push %esi
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push %ebx
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movw 0x8(%ebp), %si
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mov $0x7f, %edx
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/* prot_to_real will set %es to BOOTSEG */
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call EXT(prot_to_real) /* enter real mode */
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movw $0x4b01, %ax /* (do not) terminate disk emulation */
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movb $0x7f, %dl /* any drive */
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sti
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int $0x13
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cli
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/* save return value (actually movw %ax, %bx) */
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mov %eax, %ebx
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data32
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call EXT(real_to_prot) /* back to protected mode */
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xor %eax, %eax
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movb %bh, %al /* return value in %ax */
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pop %ebx
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pop %esi
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pop %ebp
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ret
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/*
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* int
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* biosreadlba(struct daddrpacket *daddr)
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* Read sectors using the BIOS "read extended" function
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* BIOS call "INT 0x13 Function 0x42" to read sectors from disk into memory
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* Call with %ah = 0x42
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* %dl = drive (0x0 for floppy disk, or emulated CD)
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* %ds:%si = ptr to disk address packet
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* Return:
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* %ah = 0x0 on success; err code on failure
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*/
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ENTRY(biosreadlba)
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %esi
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movw 8(%ebp), %si
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movl $0, %edx /* emulated CD is always drive 0 */
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/* prot_to_real will set %es to BOOTSEG */
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call EXT(prot_to_real) /* enter real mode */
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movw $0x4200, %ax /* subfunction */
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movb $0, %dl
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sti
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int $0x13
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cli
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/* save return value (actually movw %ax, %bx) */
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mov %eax, %ebx
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data32
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call EXT(real_to_prot) /* back to protected mode */
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xor %eax, %eax
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movb %bh, %al /* return value in %ax */
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pop %esi
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pop %ebx
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pop %ebp
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ret
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#endif /* !CDBOOT */
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/*
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* putc(ch)
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* BIOS call "INT 10H Function 0Eh" to write character to console
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* Call with %ah = 0x0e
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* %al = character
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* %bh = page
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* %bl = foreground color ( graphics modes)
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*/
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ENTRY(putc)
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %esi
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push %edi
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movb 0x8(%ebp), %cl
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call EXT(prot_to_real)
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data32
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mov $0x1, %ebx /* %bh=0, %bl=1 (blue) */
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movb $0xe, %ah
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movb %cl, %al
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sti
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int $0x10 /* display a byte */
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cli
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data32
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call EXT(real_to_prot)
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pop %edi
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pop %esi
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pop %ebx
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pop %ebp
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ret
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/*
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* getc()
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* BIOS call "INT 16H Function 00H" to read character from keyboard
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* Call with %ah = 0x0
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* Return: %ah = keyboard scan code
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* %al = ASCII character
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*/
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ENTRY(getc)
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push %ebp
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mov %esp, %ebp
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push %ebx /* save %ebx */
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push %esi
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push %edi
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call EXT(prot_to_real)
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movb $0x0, %ah
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sti
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int $0x16
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cli
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movb %al, %bl /* real_to_prot uses %eax */
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data32
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call EXT(real_to_prot)
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xor %eax, %eax
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movb %bl, %al
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pop %edi
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pop %esi
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pop %ebx
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pop %ebp
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ret
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/*
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* ischar()
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* if there is a character pending, return it; otherwise return 0
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* BIOS call "INT 16H Function 01H" to check whether a character is pending
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* Call with %ah = 0x1
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* Return:
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* If key waiting to be input:
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* %ah = keyboard scan code
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* %al = ASCII character
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* Zero flag = clear
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* else
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* Zero flag = set
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*/
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ENTRY(ischar)
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %esi
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push %edi
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call EXT(prot_to_real) /* enter real mode */
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xor %ebx, %ebx
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movb $0x1, %ah
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sti
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int $0x16
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cli
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data32
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jz nochar
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movb %al, %bl
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nochar:
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data32
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call EXT(real_to_prot)
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xor %eax, %eax
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movb %bl, %al
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pop %edi
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pop %esi
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pop %ebx
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pop %ebp
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ret
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/*
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*
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* get_diskinfo(): return a word that represents the
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* max number of sectors and heads and drives for this device
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*
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*/
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ENTRY(get_diskinfo)
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %esi
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push %edi
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movb 0x8(%ebp), %dl /* diskinfo(drive #) */
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call EXT(prot_to_real) /* enter real mode */
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movb $0x8, %ah /* ask for disk info */
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sti
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int $0x13
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cli
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jnc ok
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/*
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* Urk. Call failed. It is not supported for floppies by old BIOS's.
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* Guess it's a 15-sector floppy.
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*/
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subb %ah, %ah /* %ax = 0 */
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movb %al, %al
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movb %ah, %bh /* %bh = 0 */
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movb $2, %bl /* %bl bits 0-3 = drive type,
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bit 2 = 1.2M */
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movb $79, %ch /* max track */
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movb $15, %cl /* max sector */
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movb $1, %dh /* max head */
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movb $1, %dl /* # floppy drives installed */
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/* es:di = parameter table */
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/* carry = 0 */
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ok:
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data32
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call EXT(real_to_prot) /* back to protected mode */
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/*
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* form a longword representing all this gunk:
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* 6 bit zero
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* 10 bit max cylinder (0 based)
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* 8 bit max head (0 based)
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* 2 bit zero
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* 6 bit max sector (1 based) = # sectors
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*/
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movb %cl, %al /* Upper two bits of cylinder count */
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andl $192,%eax
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leal 0(,%eax,4),%eax /* << 2 */
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movb %ch, %al /* Lower 8 bits */
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sall $16,%eax /* << 16 */
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movb %dh, %ah /* max head */
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andb $0x3f, %cl /* mask of cylinder gunk */
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movb %cl, %al /* max sector (and # sectors) */
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pop %edi
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pop %esi
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pop %ebx
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pop %ebp
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ret
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/*
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*
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* memsize(i) : return the memory size in KB. i == 0 for conventional memory,
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* i == 1 for extended memory
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* BIOS call "INT 12H" to get conventional memory size
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* BIOS call "INT 15H, AH=88H" to get extended memory size
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* Both have the return value in AX.
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*
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*/
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ENTRY(memsize)
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %esi
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push %edi
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mov 8(%ebp), %ebx
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call EXT(prot_to_real) /* enter real mode */
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cmpb $0x1, %bl
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data32
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je xext
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sti
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int $0x12
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cli
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data32
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jmp xdone
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xext: movb $0x88, %ah
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sti
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int $0x15
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cli
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xdone:
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pushl $0 /* actually pushw $0 */
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pushl %eax /* actually pushw %ax */
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data32
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call EXT(real_to_prot)
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pop %eax
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pop %edi
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pop %esi
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pop %ebx
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pop %ebp
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ret
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