bios: Use int 0x16, ah=0x02 to probe for shift flags
[syslinux/sherbszt.git] / mbr / adjust.h
blobce8716eb53404166158a404d39cf856208882c69
1 /* -*- asm -*- -----------------------------------------------------------
3 * Copyright 2009-2014 Intel Corporation; author: H. Peter Anvin
5 * Permission is hereby granted, free of charge, to any person
6 * obtaining a copy of this software and associated documentation
7 * files (the "Software"), to deal in the Software without
8 * restriction, including without limitation the rights to use,
9 * copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom
11 * the Software is furnished to do so, subject to the following
12 * conditions:
14 * The above copyright notice and this permission notice shall
15 * be included in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
19 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
21 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
22 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24 * OTHER DEALINGS IN THE SOFTWARE.
26 * ----------------------------------------------------------------------- */
29 * adjust.h
31 * Macros to adjust the drive number
34 #ifndef ADJUST_H
35 #define ADJUST_H
37 #ifdef CTRL_80
38 .macro ADJUST_DRIVE
39 pusha
40 movb $0x02, %ah
41 int $0x16
42 testb $0x04, %al
43 popa
44 jz 1f
45 movb $0x80, %dl
47 .endm
48 #elif defined(FORCE_80)
49 .macro ADJUST_DRIVE
50 movb $0x80, %dl
51 .endm
52 #else
53 .macro ADJUST_DRIVE
54 .endm
55 #endif
57 #endif /* ADJUST_H */