diff options
Diffstat (limited to 'contrib/syslinux-4.02/dos/int2526.S')
| -rw-r--r-- | contrib/syslinux-4.02/dos/int2526.S | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/dos/int2526.S b/contrib/syslinux-4.02/dos/int2526.S new file mode 100644 index 0000000..53e63f8 --- /dev/null +++ b/contrib/syslinux-4.02/dos/int2526.S @@ -0,0 +1,78 @@ +/* ----------------------------------------------------------------------- * + * + * 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 |