source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CompatibleDPT.asm@ 21

Last change on this file since 21 was 3, checked in by Tomi Tilli, 14 years ago
File size: 6.2 KB
Line 
1; File name : CompatibleDPT.asm
2; Project name : IDE BIOS
3; Created date : 6.4.2010
4; Last update : 6.4.2010
5; Author : Tomi Tilli
6; Description : Functions for creating Disk Parameter Tables for
7; software compatibility only. These DPTs are not used
8; by our BIOS.
9
10; Section containing code
11SECTION .text
12
13;--------------------------------------------------------------------
14; Creates compatible for drives 80h and 81h. There will be stored
15; to interrupt vectors 41h and 46h.
16;
17; CompatibleDPT_CreateForDrives80hAnd81h
18; Parameters:
19; DS: RAMVARS segment
20; ES: BDA segment (zero)
21; Returns:
22; Nothing
23; Corrupts registers:
24; All except DS and ES
25;--------------------------------------------------------------------
26ALIGN JUMP_ALIGN
27CompatibleDPT_CreateForDrives80hAnd81h:
28 ; Only create compatible DPTs in full mode
29 test BYTE [cs:ROMVARS.wFlags], FLG_ROMVARS_FULLMODE
30 jz SHORT CompatibleDPT_StoreCustomDPTs
31
32 mov dl, 80h
33 call FindDPT_ForDriveNumber ; DPT to DS:DI
34 jnc SHORT .CreateForDrive81h
35 call CompatibleDPT_CreateForDrive80h
36ALIGN JUMP_ALIGN
37.CreateForDrive81h:
38 mov dl, 81h
39 call FindDPT_ForDriveNumber
40 jnc SHORT .Return
41 call CompatibleDPT_CreateForDrive81h
42ALIGN JUMP_ALIGN
43.Return:
44 ret
45
46
47;--------------------------------------------------------------------
48; Stores pointers to our custom DPTs for drives 80h and 81h.
49;
50; CompatibleDPT_StoreCustomDPTs
51; Parameters:
52; ES: BDA and interrupt vector segment (zero)
53; Returns:
54; Nothing
55; Corrupts registers:
56; DX, DI
57;--------------------------------------------------------------------
58ALIGN JUMP_ALIGN
59CompatibleDPT_StoreCustomDPTs:
60 mov dl, 80h
61 call FindDPT_ForDriveNumber ; DPT to DS:DI
62 jnc SHORT .FindForDrive81h
63 mov [es:INTV_HD0DPT*4], di
64 mov [es:INTV_HD0DPT*4+2], ds
65ALIGN JUMP_ALIGN
66.FindForDrive81h:
67 inc dx
68 call FindDPT_ForDriveNumber
69 jnc SHORT .Return
70 mov [es:INTV_HD1DPT*4], di
71 mov [es:INTV_HD1DPT*4+2], ds
72ALIGN JUMP_ALIGN
73.Return:
74 ret
75
76
77;--------------------------------------------------------------------
78; Copies parameters from our custom DPT struct to a
79; standard COMPATIBLE_FDPT or COMPATIBLE_EDPT struct.
80;
81; CompatibleDPT_CreateForDrive80h
82; CompatibleDPT_CreateForDrive81h
83; Parameters:
84; DS:DI: Ptr to DPT
85; ES: BDA and interrupt vector segment (zero)
86; Returns:
87; Nothing
88; Corrupts registers:
89; AX, BX, CX, DX, SI
90;--------------------------------------------------------------------
91ALIGN JUMP_ALIGN
92CompatibleDPT_CreateForDrive80h:
93 mov si, FULLRAMVARS.drv80hCompDPT ; DS:SI now points compatible DPT
94 call CompatibleDPT_CopyFromCustom
95 mov [es:INTV_HD0DPT*4], si
96 mov [es:INTV_HD0DPT*4+2], ds
97 ret
98ALIGN JUMP_ALIGN
99CompatibleDPT_CreateForDrive81h:
100 mov si, FULLRAMVARS.drv81hCompDPT ; DS:SI now points compatible DPT
101 call CompatibleDPT_CopyFromCustom
102 mov [es:INTV_HD1DPT*4], si
103 mov [es:INTV_HD1DPT*4+2], ds
104 ret
105
106
107;--------------------------------------------------------------------
108; Copies parameters from our custom DPT struct to a
109; standard COMPATIBLE_FDPT or COMPATIBLE_EDPT struct.
110;
111; CompatibleDPT_CopyFromCustom
112; Parameters:
113; DS:SI: Ptr to COMPATIBLE_FDPT or COMPATIBLE_EDPT
114; DS:DI: Ptr to DPT
115; Returns:
116; Nothing
117; Corrupts registers:
118; AX, BX, CX, DX
119;--------------------------------------------------------------------
120ALIGN JUMP_ALIGN
121CompatibleDPT_CopyFromCustom:
122 call AccessDPT_GetLCHSfromPCHS ; AX=Lsects, BX=Lcyls, DX=Lheads
123 test BYTE [di+DPT.bFlags], FLG_DPT_EBIOS ; Drive larger than 504 MiB?
124 jnz SHORT CompatibleDPT_CopyFromCustomToEDPT
125 ; Fall to CompatibleDPT_CopyFromCustomToFDPT
126
127;--------------------------------------------------------------------
128; Copies parameters from our custom DPT struct to a
129; standard COMPATIBLE_FDPT struct for drives up to 504 MiB.
130;
131; CompatibleDPT_CopyFromCustomToFDPT
132; Parameters:
133; AX: L-CHS sectors per track
134; BX: L-CHS cylinders
135; DX: L-CHS heads
136; DS:SI: Ptr to COMPATIBLE_FDPT
137; DS:DI: Ptr to DPT
138; Returns:
139; Nothing
140; Corrupts registers:
141; AX, BX
142;--------------------------------------------------------------------
143;ALIGN JUMP_ALIGN
144CompatibleDPT_CopyFromCustomToFDPT:
145 mov [si+COMPATIBLE_FDPT.wCyls], bx
146 mov [si+COMPATIBLE_FDPT.bHeads], dl
147 mov [si+COMPATIBLE_FDPT.bSectPerTrack], al
148 mov WORD [si+COMPATIBLE_FDPT.wWrPreCmpCyl], -1
149 mov al, [di+DPT.bDrvCtrl]
150 mov [si+COMPATIBLE_FDPT.bDrvCtrl], al
151 mov BYTE [si+COMPATIBLE_FDPT.bNormTimeout], B_TIMEOUT_BSY
152 mov BYTE [si+COMPATIBLE_FDPT.bFormatTimeout], B_TIMEOUT_DRQ
153 mov BYTE [si+COMPATIBLE_FDPT.bCheckTimeout], B_TIMEOUT_DRQ
154 dec bx
155 mov [si+COMPATIBLE_FDPT.wLZoneCyl], bx
156 ret
157
158
159;--------------------------------------------------------------------
160; Copies parameters from our custom DPT struct to a
161; standard COMPATIBLE_EDPT struct.
162;
163; CompatibleDPT_CopyFromCustomToEDPT
164; Parameters:
165; AX: L-CHS sectors per track
166; BX: L-CHS cylinders
167; DX: L-CHS heads
168; DS:SI: Ptr to COMPATIBLE_EDPT
169; DS:DI: Ptr to DPT
170; Returns:
171; Nothing
172; Corrupts registers:
173; AX, BX, CX, DX
174;--------------------------------------------------------------------
175ALIGN JUMP_ALIGN
176CompatibleDPT_CopyFromCustomToEDPT:
177 mov [si+COMPATIBLE_EDPT.wLCyls], bx
178 mov [si+COMPATIBLE_EDPT.bLHeads], dl
179 mov BYTE [si+COMPATIBLE_EDPT.bSignature], COMPATIBLE_EDPT_SIGNATURE
180 mov [si+COMPATIBLE_EDPT.bPSect], al
181 mov [si+COMPATIBLE_EDPT.bLSect], al
182 mov al, [di+DPT.bDrvCtrl]
183 mov [si+COMPATIBLE_EDPT.bDrvCtrl], al
184 mov ax, [di+DPT.wPCyls]
185 mov [si+COMPATIBLE_EDPT.wPCyls], ax
186 mov al, [di+DPT.bPHeads]
187 mov [si+COMPATIBLE_EDPT.bPHeads], al
188 ; Fall to CompatibleDPT_StoreChecksum
189
190;--------------------------------------------------------------------
191; Stores checksum byte to the end of COMPATIBLE_EDPT struct.
192;
193; CompatibleDPT_StoreChecksum
194; Parameters:
195; DS:SI: Ptr to COMPATIBLE_EDPT
196; Returns:
197; Nothing
198; Corrupts registers:
199; AX, BX, CX
200;--------------------------------------------------------------------
201;ALIGN JUMP_ALIGN
202CompatibleDPT_StoreChecksum:
203 xor ax, ax
204 xor bx, bx
205 mov cx, COMPATIBLE_EDPT_size-1
206ALIGN JUMP_ALIGN
207.SumLoop:
208 add al, [bx+si]
209 inc bx
210 loop .SumLoop
211 neg al
212 mov [si+COMPATIBLE_EDPT.bChecksum], al
213 ret
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