source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH8h_HParams.asm@ 319

Last change on this file since 319 was 294, checked in by krille_n_@…, 13 years ago

Commit 2/2 (BIOS):

  • Fixed a bug in AH1h_HStatus.asm.
  • Minor optimizations.
  • Fixed spelling and did some cleaning.
File size: 5.7 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Int 13h function AH=8h, Read Disk Drive Parameters.
3
4; Section containing code
5SECTION .text
6
7;--------------------------------------------------------------------
8; Int 13h function AH=8h, Read Disk Drive Parameters.
9;
10; AH8h_HandlerForReadDiskDriveParameters
11; Parameters:
12; DL: Translated Drive number
13; DS:DI: Ptr to DPT (in RAMVARS segment)
14; SS:BP: Ptr to IDEPACK
15; Returns with INTPACK:
16; BL: Drive Type (for floppies only)
17; CH: Maximum cylinder number, bits 7...0
18; CL: Bits 7...6: Cylinder number bits 9...8
19; Bits 5...0: Maximum sector number (1...63)
20; DH: Maximum head number (0...254)
21; DL: Number of drives
22; ES:DI: Floppy DPT (for floppies only)
23; AH: Int 13h/40h floppy return status
24; CF: 0 if successful, 1 if error
25;--------------------------------------------------------------------
26AH8h_HandlerForReadDiskDriveParameters:
27 test di,di
28 jnz SHORT .OurDrive
29
30 call Int13h_CallPreviousInt13hHandler
31 jnc SHORT .MidGame
32 jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
33
34.OurDrive:
35 call AH8h_GetDriveParameters
36
37%ifdef MODULE_SERIAL_FLOPPY
38 push cs ; setup registers if we are a floppy drive, in all cases
39 pop es ; if it is not a floppy drive, these values will not be put in INTPACK
40 mov di, AH8h_FloppyDPT
41%endif
42 ;; fall-through
43
44.MidGame:
45 call RamVars_GetCountOfKnownDrivesToAX ; assume hard disk for now, will discard if for floppies
46
47 test byte [bp+IDEPACK.intpack+INTPACK.dl], 080h
48 jnz .Done
49
50 mov [bp+IDEPACK.intpack+INTPACK.bl], bl
51
52 mov [bp+IDEPACK.intpack+INTPACK.es], es
53 mov [bp+IDEPACK.intpack+INTPACK.di], di
54
55 call FloppyDrive_GetCountToAX
56
57.Done:
58 mov ah, dh
59
60 mov [bp+IDEPACK.intpack+INTPACK.cx], cx
61 xchg [bp+IDEPACK.intpack+INTPACK.dx], ax ; recover DL for BDA last status byte determination
62
63 xor ah, ah
64%ifdef MODULE_SERIAL_FLOPPY
65 jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH_ALHasDriveNumber
66%else
67 jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
68%endif
69
70
71;--------------------------------------------------------------------
72; Returns L-CHS parameters for drive and total hard disk count.
73;
74; AH8h_GetDriveParameters
75; Parameters:
76; DS:DI: Ptr to DPT (in RAMVARS segment)
77; Returns:
78; CH: Maximum cylinder number, bits 7...0
79; CL: Bits 7...6: Cylinder number bits 9...8
80; Bits 5...0: Maximum sector number (1...63)
81; DH: Maximum head number (0...254)
82; Corrupts registers:
83; AX, BX
84;--------------------------------------------------------------------
85AH8h_GetDriveParameters:
86 call AccessDPT_GetLCHStoAXBLBH
87 ; Fall to .PackReturnValues
88
89;--------------------------------------------------------------------
90; Packs L-CHS values to INT 13h, AH=08h return values.
91;
92; .PackReturnValues
93; Parameters:
94; AX: Number of L-CHS cylinders available (1...1024)
95; BL: Number of L-CHS heads (1...255)
96; BH: Number of L-CHS sectors per track (1...63)
97; DS: RAMVARS segment
98; Returns:
99; CH: Maximum cylinder number, bits 7...0
100; CL: Bits 7...6: Cylinder number bits 9...8
101; Bits 5...0: Maximum sector number (1...63)
102; DH: Maximum head number (0...254)
103; Corrupts registers:
104; AX, BX
105;--------------------------------------------------------------------
106.PackReturnValues:
107 dec ax ; AX = Number of last cylinder
108 dec bx ; BL = Number of last head
109 xchg cx, ax
110 xchg cl, ch ; CH = Last cylinder bits 0...7
111 eROR_IM cl, 2 ; CL bits 6...7 = Last cylinder bits 8...9
112 or cl, bh ; CL bits 0...5 = Sectors per track
113 mov dh, bl ; DH = Maximum head number
114
115%ifdef MODULE_SERIAL_FLOPPY
116 mov bl,[di+DPT.bFlagsHigh]
117%ifndef CHECK_FOR_UNUSED_ENTRYPOINTS ; not sure why this is needed for preprocessor-only
118 eSHR_IM bl,FLGH_DPT_SERIAL_FLOPPY_TYPE_FIELD_POSITION
119%endif
120%endif
121 ret
122
123%ifdef MODULE_SERIAL_FLOPPY
124;
125; Floppy Disk Parameter Table. There is no way to specify more than one of these
126; for any given system, so no way to make this drive or media specific.
127; So we return fixed values out of the ROM for callers who might be expecting this information.
128;
129; On AT systems, we return the information for a 1.44 MB disk,
130; and on XT systems, we return the information for a 360 KB disk.
131;
132AH8h_FloppyDPT:
133%ifdef USE_AT
134 db 0ah << 4 | 0fh ; Offset 0: Drive timings, 1.44MB values
135%else
136 db 0dh << 4 | 0fh ; Offset 0: Drive timings, 360KB values
137%endif
138
139 db 1h << 1 | 0 ; Offset 1: Typical values of 1 for head load time
140 ; DMA used (although it actually is not, but is more restrictive)
141 db 25h ; Offset 2: Inactivity motor turn-off delay,
142 ; Typical value of 25h for 2 second delay
143 db 02h ; Offset 3: Sector size, always 512
144
145%ifdef USE_AT
146 db 12h ; Offset 4: Sectors per track, 1.44MB value
147 db 1bh ; Offset 5: Sector gap, 1.44MB value
148%else
149 db 09h ; Offset 4: Sectors per track, 360KB value
150 db 2ah ; Offset 5: Sector gap, 360KB value
151%endif
152
153 db 0ffh ; Offset 6: Data length
154
155%ifdef USE_AT
156 db 6ch ; Offset 7: Format gap length, 1.44MB value
157%else
158 db 50h ; Offset 7: Format gap length, 360KB value
159%endif
160
161 db 0f6h ; Offset 8: Fill byte for format
162 db 0fh ; Offset 9: Head setting time
163 db 08h ; Offset A: Wait for motor startup time
164
165%ifdef USE_AT
166 db 79 ; Offset B: Maximum track number, 1.44MB value
167 db 0 ; Offset C: Data transfer rate, 1.44MB value
168 db 4 ; Offset D: Diskette CMOS drive type, 1.44MB value
169%else
170 db 39 ; Offset B: Maximum track number, 360KB value
171 db 80h ; Offset C: Data transfer rate, 360KB value
172 db 1 ; Offset D: Diskette CMOS drive type, 360KB value
173%endif
174%endif
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