/* * 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: src/sys/i386/boot/biosboot/bios.S,v 1.15 1999/08/28 00:43:11 peter Exp $ * $DragonFly: src/sys/i386/boot/biosboot/Attic/bios.S,v 1.2 2003/06/17 04:28:34 dillon Exp $ */ /* 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. */ /* * 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 0x13 Function 0x2" to read sectors from disk into memory * Call with %ah = 0x2 * %al = number of sectors * %ch = cylinder * %cl = sector * %dh = head * %dl = drive (0x80 for hard disk, 0x0 for floppy disk) * %es:%bx = segment:offset of buffer * Return: * %al = 0x0 on success; err code on failure */ ENTRY(biosread) push %ebp mov %esp, %ebp push %ebx push %esi push %edi movb 0x10(%ebp), %dh movw 0x0c(%ebp), %cx /* cylinder; the highest 2 bits of cyl is in %cl */ xchgb %ch, %cl rorb $2, %cl movb 0x14(%ebp), %al orb %al, %cl incb %cl /* sector; sec starts from 1, not 0 */ movb 0x8(%ebp), %dl /* device */ movl 0x1c(%ebp), %ebx /* offset */ /* prot_to_real will set %es to BOOTSEG */ call EXT(prot_to_real) /* enter real mode */ movb $0x2, %ah /* subfunction */ addr32 movb 0x18(%ebp), %al /* number of sectors */ 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 %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 */ /* * putc(ch) * BIOS call "INT 10H Function 0Eh" to write character to console * Call with %ah = 0x0e * %al = character * %bh = page * %bl = foreground color ( graphics modes) */ ENTRY(putc) push %ebp mov %esp, %ebp push %ebx push %esi push %edi movb 0x8(%ebp), %cl call EXT(prot_to_real) data32 mov $0x1, %ebx /* %bh=0, %bl=1 (blue) */ movb $0xe, %ah movb %cl, %al sti int $0x10 /* display a byte */ cli data32 call EXT(real_to_prot) pop %edi pop %esi pop %ebx pop %ebp ret /* * getc() * BIOS call "INT 16H Function 00H" to read character from keyboard * Call with %ah = 0x0 * Return: %ah = keyboard scan code * %al = ASCII character */ ENTRY(getc) push %ebp mov %esp, %ebp push %ebx /* save %ebx */ push %esi push %edi call EXT(prot_to_real) movb $0x0, %ah sti int $0x16 cli movb %al, %bl /* real_to_prot uses %eax */ 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 16H 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 * Zero flag = clear * else * Zero flag = set */ ENTRY(ischar) push %ebp mov %esp, %ebp push %ebx push %esi push %edi call EXT(prot_to_real) /* enter real mode */ xor %ebx, %ebx movb $0x1, %ah sti int $0x16 cli data32 jz nochar movb %al, %bl nochar: 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) 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 */ movb $0x8, %ah /* ask for disk info */ sti int $0x13 cli jnc ok /* * Urk. Call failed. It is not supported for floppies by old BIOS's. * Guess it's a 15-sector floppy. */ 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 $15, %cl /* max sector */ movb $1, %dh /* max head */ movb $1, %dl /* # floppy drives installed */ /* es:di = parameter table */ /* carry = 0 */ ok: data32 call EXT(real_to_prot) /* back to protected mode */ /* * form a longword representing all this gunk: * 6 bit zero * 10 bit max cylinder (0 based) * 8 bit max head (0 based) * 2 bit zero * 6 bit max sector (1 based) = # sectors */ movb %cl, %al /* Upper two bits of cylinder count */ andl $192,%eax leal 0(,%eax,4),%eax /* << 2 */ movb %ch, %al /* Lower 8 bits */ sall $16,%eax /* << 16 */ movb %dh, %ah /* max head */ andb $0x3f, %cl /* mask of cylinder gunk */ movb %cl, %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 * BIOS call "INT 12H" to get conventional memory size * BIOS call "INT 15H, AH=88H" to get extended memory size * Both have the return value in AX. * */ ENTRY(memsize) push %ebp mov %esp, %ebp push %ebx push %esi push %edi mov 8(%ebp), %ebx call EXT(prot_to_real) /* enter real mode */ cmpb $0x1, %bl data32 je xext sti int $0x12 cli data32 jmp xdone xext: movb $0x88, %ah sti int $0x15 cli xdone: pushl $0 /* actually pushw $0 */ pushl %eax /* actually pushw %ax */ data32 call EXT(real_to_prot) pop %eax pop %edi pop %esi pop %ebx pop %ebp ret