source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm @ 258

Last change on this file since 258 was 258, checked in by gregli@…, 12 years ago

Added floppy drive emulation over the serial connection (MODULE_SERIAL_FLOPPY). Along the way, various optimizations were made to stay within the 8K ROM size target. Also, serial code now returns the number of sectors transferred.
File size: 1.6 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...128)
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 (we never return error code 11h)
26;               Number of sectors actually read (only valid if CF set for someBIOSes)
27;       CF:     0 if successfull, 1 if error
28;--------------------------------------------------------------------
29ALIGN JUMP_ALIGN
30AH2h_HandlerForReadDiskSectors:
31    call    Prepare_BufferToESSIforOldInt13hTransfer
32    call    Prepare_GetOldInt13hCommandIndexToBX
33    mov     ah, [cs:bx+g_rgbReadCommandLookup]
34    mov     bx, TIMEOUT_AND_STATUS_TO_WAIT(TIMEOUT_DRQ, FLG_STATUS_DRQ)
35%ifdef USE_186
36    push    Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAHandTransferredSectorsFromCL
37    jmp     Idepack_TranslateOldInt13hAddressAndIssueCommandFromAH
38%else
39    call    Idepack_TranslateOldInt13hAddressAndIssueCommandFromAH
40    jmp     Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAHandTransferredSectorsFromCL
41%endif
42
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