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/* ----------------------------------------------------------------------- *
*
* Copyright 1998-2008 H. Peter Anvin - All Rights Reserved
* Copyright 2009 Intel Corporation; author: H. Peter Anvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* int 0x25 and 0x26 direct sector access
*
* Use assembly wrapper functions for these system calls, since unlike
* int 0x21 calls they are "dirty" and can destroy unrelated registers.
*
* NOTE: these all assume the data buffer is in the data segment, i.e.
* %ds == %es == dio.bufseg.
*
* Usage: int int25_read_sector(drive, dio)
* Usage: int int26_write_sector(drive, dio)
*/
.code16gcc
.text
.globl int25_read_sector
.type int25_read_sector, @function
int25_read_sector:
pushl %ebp
pushl %edi
pushl %esi
pushl %ebx
decw %ax /* AL = drive number (0 = A:) */
movw %dx, %bx /* BX = dio structure */
movw 6(%bx), %dx /* DX = data buffer */
movw $-1, %cx
int $0x25
jc 1f
xorw %ax, %ax /* Error code: 0 = no error */
1:
popfw
movzwl %ax, %eax
popl %ebx
popl %esi
popl %edi
popl %ebp
retl
.size int25_read_sector, .-int25_read_sector
.globl int26_write_sector
.type int26_write_sector, @function
int26_write_sector:
pushl %ebp
pushl %edi
pushl %esi
pushl %ebx
decw %ax /* AL = drive number (0 = A:) */
movw %dx, %bx /* BX = dio structure */
movw 6(%bx), %dx /* DX = data buffer */
movw $-1, %cx
int $0x26
jc 1f
xorw %ax, %ax /* Error code: 0 = no error */
1:
popfw
movzwl %ax, %eax
popl %ebx
popl %esi
popl %edi
popl %ebp
retl
.size int26_write_sector, .-int26_write_sector
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