source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AHCh_HSeek.asm@ 90

Last change on this file since 90 was 84, checked in by krille_n_@…, 14 years ago

Minor size optimizations in various files.

File size: 2.0 KB
Line 
1; File name : AHCh_HSeek.asm
2; Project name : IDE BIOS
3; Created date : 13.12.2007
4; Last update : 14.1.2011
5; Author : Tomi Tilli,
6; : Krister Nordvall (optimizations)
7; Description : Int 13h function AH=Ch, Seek.
8
9; Section containing code
10SECTION .text
11
12;--------------------------------------------------------------------
13; Int 13h function AH=Ch, Seek.
14;
15; AHCh_HandlerForSeek
16; Parameters:
17; AH: Bios function Ch
18; CH: Cylinder number, bits 7...0
19; CL: Bits 7...6: Cylinder number bits 9 and 8
20; Bits 5...0: Starting sector number (1...63)
21; DH: Starting head number (0...255)
22; DL: Drive number
23; Parameters loaded by Int13h_Jump:
24; DS: RAMVARS segment
25; Returns:
26; AH: BIOS Error code
27; CF: 0 if succesfull, 1 if error
28; IF: 1
29; Corrupts registers:
30; Flags
31;--------------------------------------------------------------------
32ALIGN JUMP_ALIGN
33AHCh_HandlerForSeek:
34 push dx
35 push cx
36 push bx
37 push ax
38%ifndef USE_186
39 call AHCh_SeekToCylinder
40 jmp Int13h_PopXRegsAndReturn
41%else
42 push Int13h_PopXRegsAndReturn
43 ; Fall through to AHCh_SeekToCylinder
44%endif
45
46
47;--------------------------------------------------------------------
48; Seeks to a cylinder.
49;
50; AHCh_SeekToCylinder
51; Parameters:
52; CH: Cylinder number, bits 7...0
53; CL: Bits 7...6: Cylinder number bits 9 and 8
54; Bits 5...0: Starting sector number (1...63)
55; DH: Starting head number (0...255)
56; DL: Drive Number
57; DS: RAMVARS segment
58; Returns:
59; DS:DI: Ptr to DPT
60; AH: BIOS Error code
61; CF: 0 if succesfull, 1 if error
62; Corrupts registers:
63; AL, BX, CX, DX
64;--------------------------------------------------------------------
65ALIGN JUMP_ALIGN
66AHCh_SeekToCylinder:
67 call FindDPT_ForDriveNumber ; DS:DI now points to DPT
68 mov ax, HCMD_SEEK<<8 ; Load cmd to AH, AL=zero sector cnt
69 call HCommand_OutputCountAndLCHSandCommand
70 jc SHORT .Return ; Return if error
71 mov bx, di ; DS:BX now points to DPT
72 jmp HStatus_WaitIrqOrRdy ; Wait for IRQ or RDY
73.Return:
74 ret
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