1130b656e5
This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
334 lines
6.6 KiB
ArmAsm
334 lines
6.6 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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* Ported to PC-9801 by Yoshio Kimura
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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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/*
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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 0x1B Function 0xn6" to read sectors from disk into memory
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* Call with %ah = 0xd6(for floppy disk) or 0x06(for hard disk)
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* %al = DA/UA
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* %bx = data length
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* %ch = sector size(for floppy) or cylinder(for hard)
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* %cl = cylinder
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* %dh = head
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* %dl = sector
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* %es:%bp = 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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push %ecx
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push %edx
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push %es
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movb 0x14(%ebp), %dl /* sector */
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movb 0x10(%ebp), %dh /* head */
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movw 0x0c(%ebp), %cx /* cylinder */
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movb 0x08(%ebp), %al /* DA/UA */
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movb $0x06, %ah
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andb $0xf0, %al
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cmpb $0x90, %al
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jnz 1f
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incb %dl
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movb $0x02, %ch
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movb $0xd6, %ah
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1:
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movb 0x08(%ebp), %al
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movl %eax, %ebx
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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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mov %ebx, %eax
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xor %ebx, %ebx
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addr32
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movb 0x18(%ebp), %bl /* number of sectors */
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data32
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shl $9, %ebx
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data32
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push %ebx
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addr32
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data32
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mov 0x1c(%ebp), %ebx
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data32
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mov %ebx, %ebp
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data32
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pop %ebx
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int $0x1b
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jc 1f
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xor %eax, %eax
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1:
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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 %es
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pop %edx
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pop %ecx
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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 18H 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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int $0x18
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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 18H 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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* %bh = 1
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* else
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* %bh = 0
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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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int $0x18
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andb %bh, %bh
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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 %es
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push %ebx
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push %esi
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push %edi
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push %ecx
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push %edx
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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 %dl, %al /* ask for disk info */
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andb $0xf0, %al
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cmpb $0x90, %al
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jz fdd
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movb %dl, %al
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movb $0x84, %ah
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int $0x1b
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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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fdd:
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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 $1, %cl /* # floppy drives installed */
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movb $2, %dh /* max head */
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movb $15, %dl /* max sector */
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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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* 16 bit cylinder
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* 8 bit head
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* 8 bit sector
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*/
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mov %ecx, %eax
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sall $16,%eax /* << 16 */
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movb %dh, %ah /* max head */
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movb %dl, %al /* max sector (and # sectors) */
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pop %edx
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pop %ecx
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pop %edi
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pop %esi
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pop %ebx
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pop %es
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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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* 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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xor %eax, %eax
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cmpb $0x01, %bl
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jnz memcnv
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memext:
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movb 0xA1401 - BOOTSEG * 0x10, %al
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shll $7, %eax
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xorl %ebx, %ebx
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movw 0xA1594 - BOOTSEG * 0x10, %bx
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shll $10, %ebx
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addl %ebx, %eax
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jmp xdone
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memcnv:
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movb 0xA1501 - BOOTSEG * 0x10, %al
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andb $0x07, %al
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incl %eax
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shll $7, %eax
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xdone:
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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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