source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm@ 161

Last change on this file since 161 was 158, checked in by Tomi Tilli, 14 years ago

Changes to XTIDE Universal BIOS:

  • Optimized few bytes.
File size: 2.1 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Int 13h function AH=2h, Read Disk Sectors.
3
4; Section containing code
5SECTION .text
6
7;--------------------------------------------------------------------
8; Int 13h function AH=2h, Read Disk Sectors.
9;
10; AH2h_HandlerForReadDiskSectors
11; Parameters:
12; AL, CX, DH, ES: Same as in INTPACK
13; DL: Translated Drive number
14; DS:DI: Ptr to DPT (in RAMVARS segment)
15; SS:BP: Ptr to IDEPACK
16; Parameters on INTPACK:
17; AL: Number of sectors to read (1...255)
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; ES:BX: Pointer to buffer recieving data
23; Returns with INTPACK:
24; AH: Int 13h/40h floppy return status
25; AL: Burst error length if AH returns 11h, undefined otherwise
26; CF: 0 if successfull, 1 if error
27;--------------------------------------------------------------------
28ALIGN JUMP_ALIGN
29AH2h_HandlerForReadDiskSectors:
30 cmp BYTE [bp+IDEPACK.intpack+INTPACK.al], 0
31 je SHORT AH2h_ExitInt13hSinceSectorCountInIntpackIsZero
32
33 mov ah, COMMAND_READ_SECTORS ; Load sector mode command
34 test BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
35 eCMOVNZ ah, COMMAND_READ_MULTIPLE ; Load block mode command
36 mov bx, TIMEOUT_AND_STATUS_TO_WAIT(TIMEOUT_DRQ, FLG_STATUS_DRQ)
37 mov si, [bp+IDEPACK.intpack+INTPACK.bx]
38%ifdef USE_186
39 push Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
40 jmp Idepack_TranslateOldInt13hAddressAndIssueCommandFromAH
41%else
42 call Idepack_TranslateOldInt13hAddressAndIssueCommandFromAH
43 jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
44%endif
45
46
47;--------------------------------------------------------------------
48; AH2h_ExitInt13hSinceSectorCountInIntpackIsZero
49; Parameters:
50; Nothing
51; Returns:
52; Jumps to Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
53;--------------------------------------------------------------------
54AH2h_ExitInt13hSinceSectorCountInIntpackIsZero:
55 mov ah, RET_HD_INVALID
56 jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
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