/* * 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. * * from: Mach, Revision 2.2 92/04/04 11:34:26 rpd * $FreeBSD$ */ /* 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. */ /* * Ported to PC-9801 by Yoshio Kimura */ /* * Extensions for El Torito CD-ROM booting: * * Copyright © 1997 Pluto Technologies International, Inc. Boulder CO * Copyright © 1997 interface business GmbH, Dresden. * All rights reserved. * * This code has been written by Jörg Wunsch, Dresden. * Direct comments to . * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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. * */ .file "bios.s" #include "asm.h" .text #ifndef CDBOOT /* * biosread(dev, cyl, head, sec, nsec, offset) * Read "nsec" sectors from disk to offset "offset" in boot segment * BIOS call "INT 0x1B Function 0xn6" to read sectors from disk into memory * Call with %ah = 0xd6(for floppy disk) or 0x06(for hard disk) * %al = DA/UA * %bx = data length * %ch = sector size(for floppy) or cylinder(for hard) * %cl = cylinder * %dh = head * %dl = sector * %es:%bp = segment:offset of buffer * Return: * %al = 0x0 on success; err code on failure */ ENTRY(biosread) .code32 push %ebp mov %esp, %ebp push %ebx push %esi push %edi movb 0x14(%ebp), %dl /* sector */ movb 0x10(%ebp), %dh /* head */ movw 0x0c(%ebp), %cx /* cylinder */ movb 0x08(%ebp), %al /* DA/UA */ movb $0x06, %ah andb $0xf0, %al cmpb $0x30, %al jz fd cmpb $0x90, %al jnz 1f fd: incb %dl movb $0x02, %ch movb $0xd6, %ah 1: movb 0x08(%ebp), %al movl %eax, %ebx /* prot_to_real will set %es to BOOTSEG */ call EXT(prot_to_real) /* enter real mode */ mov %ebx, %eax xor %ebx, %ebx addr32 movb 0x18(%ebp), %bl /* number of sectors */ .code16 shl $9, %ebx push %ebx .code32 addr32 data32 mov 0x1c(%ebp), %ebx .code16 mov %ebx, %ebp pop %ebx int $0x1b jc 1f .code32 xor %eax, %eax 1: /* save return value (actually movw %ax, %bx) */ mov %eax, %ebx data32 call EXT(real_to_prot) /* back to protected mode */ xor %eax, %eax movb %bh, %al /* return value in %ax */ pop %edi pop %esi pop %ebx pop %ebp ret #else /* CDBOOT */ /* * int * getbootspec(struct specpacket *offset) * * Read CD-ROM boot specification packet to "offset". */ ENTRY(getbootspec) push %ebp mov %esp, %ebp push %esi push %ebx movw 0x8(%ebp), %si mov $0x7f, %edx /* prot_to_real will set %es to BOOTSEG */ call EXT(prot_to_real) /* enter real mode */ movw $0x4b01, %ax /* (do not) terminate disk emulation */ movb $0x7f, %dl /* any drive */ sti int $0x13 cli /* save return value (actually movw %ax, %bx) */ mov %eax, %ebx data32 call EXT(real_to_prot) /* back to protected mode */ xor %eax, %eax movb %bh, %al /* return value in %ax */ pop %ebx pop %esi pop %ebp ret /* * int * biosreadlba(struct daddrpacket *daddr) * Read sectors using the BIOS "read extended" function * BIOS call "INT 0x13 Function 0x42" to read sectors from disk into memory * Call with %ah = 0x42 * %dl = drive (0x0 for floppy disk, or emulated CD) * %ds:%si = ptr to disk address packet * Return: * %ah = 0x0 on success; err code on failure */ ENTRY(biosreadlba) push %ebp mov %esp, %ebp push %ebx push %esi movw 8(%ebp), %si movl $0, %edx /* emulated CD is always drive 0 */ /* prot_to_real will set %es to BOOTSEG */ call EXT(prot_to_real) /* enter real mode */ movw $0x4200, %ax /* subfunction */ movb $0, %dl sti int $0x13 cli /* save return value (actually movw %ax, %bx) */ mov %eax, %ebx data32 call EXT(real_to_prot) /* back to protected mode */ xor %eax, %eax movb %bh, %al /* return value in %ax */ pop %esi pop %ebx pop %ebp ret #endif /* !CDBOOT */ /* * getc() * BIOS call "INT 18H Function 00H" to read character from keyboard * Call with %ah = 0x0 * Return: %ah = keyboard scan code * %al = ASCII character */ ENTRY(getc) .code32 push %ebp mov %esp, %ebp push %ebx /* save %ebx */ push %esi push %edi call EXT(prot_to_real) .code16 movb $0x0, %ah int $0x18 movb %al, %bl /* real_to_prot uses %eax */ .code32 data32 call EXT(real_to_prot) xor %eax, %eax movb %bl, %al pop %edi pop %esi pop %ebx pop %ebp ret /* * ischar() * if there is a character pending, return it; otherwise return 0 * BIOS call "INT 18H Function 01H" to check whether a character is pending * Call with %ah = 0x1 * Return: * If key waiting to be input: * %ah = keyboard scan code * %al = ASCII character * %bh = 1 * else * %bh = 0 */ ENTRY(ischar) .code32 push %ebp mov %esp, %ebp push %ebx push %esi push %edi call EXT(prot_to_real) /* enter real mode */ xor %ebx, %ebx .code16 movb $0x1, %ah int $0x18 andb %bh, %bh data32 jz nochar movb %al, %bl nochar: .code32 data32 call EXT(real_to_prot) xor %eax, %eax movb %bl, %al pop %edi pop %esi pop %ebx pop %ebp ret /* * * get_diskinfo(): return a word that represents the * max number of sectors and heads and drives for this device * */ ENTRY(get_diskinfo) .code32 push %ebp mov %esp, %ebp push %ebx push %esi push %edi movb 0x8(%ebp), %dl /* diskinfo(drive #) */ call EXT(prot_to_real) /* enter real mode */ .code16 movb %dl, %al /* ask for disk info */ andb $0xf0, %al cmpb $0x30, %al jz fdd4 cmpb $0x90, %al jz fdd movb %dl, %al movb $0x84, %ah int $0x1b jnc ok /* * Urk. Call failed. It is not supported for floppies by old BIOS's. * Guess it's a 15-sector floppy. */ fdd4: movb $18, %dl jmp 1f fdd: movb $15, %dl /* max sector */ 1: subb %ah, %ah /* %ax = 0 */ movb %al, %al movb %ah, %bh /* %bh = 0 */ movb $2, %bl /* %bl bits 0-3 = drive type, bit 2 = 1.2M */ movb $79, %ch /* max track */ movb $1, %cl /* # floppy drives installed */ movb $2, %dh /* max head */ /* es:di = parameter table */ /* carry = 0 */ ok: .code32 data32 call EXT(real_to_prot) /* back to protected mode */ /* * form a longword representing all this gunk: * 16 bit cylinder * 8 bit head * 8 bit sector */ mov %ecx, %eax sall $16,%eax /* << 16 */ movb %dh, %ah /* max head */ movb %dl, %al /* max sector (and # sectors) */ pop %edi pop %esi pop %ebx pop %ebp ret /* * * memsize(i) : return the memory size in KB. i == 0 for conventional memory, * i == 1 for extended memory * Both have the return value in AX. * */ ENTRY(memsize) .code32 push %ebp mov %esp, %ebp push %ebx push %esi push %edi mov 8(%ebp), %ebx xor %eax, %eax cmpb $0x01, %bl jnz memcnv memext: movb 0xA1401 - BOOTSEG * 0x10, %al shll $7, %eax xorl %ebx, %ebx movw 0xA1594 - BOOTSEG * 0x10, %bx shll $10, %ebx addl %ebx, %eax jmp xdone memcnv: movb 0xA1501 - BOOTSEG * 0x10, %al andb $0x07, %al incl %eax shll $7, %eax xdone: pop %edi pop %esi pop %ebx pop %ebp ret