source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/MemoryMappedIDE/MemIdeTransfer.asm@ 247

Last change on this file since 247 was 242, checked in by krille_n_@…, 13 years ago

Changes:

  • Optimizations (both for size and speed) in IdeTransfer.asm and MemIdeTransfer.asm
  • Fixed a bug where the SingleByteRead/Write functions in IdeTransfer.asm would fail on 128 sector transfers.
  • Fixed some typos and errors in general, comments etc.
File size: 7.6 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Memory mapped IDE Device transfer functions.
3
4; Structure containing variables for PIO transfer functions.
5; This struct must not be larger than IDEPACK without INTPACK.
6struc MEMPIOVARS
7 .wWordsInBlock resb 2 ; 0, Block size in WORDs
8 .wWordsLeft resb 2 ; 2, WORDs left to transfer
9 .wWordsDone resb 2 ; 4, Number of sectors xferred
10 ; TODO: The above word vars could just as well be byte vars?
11 resb 1 ; 6,
12 resb 1 ; 7, IDEPACK.bDeviceControl
13 .fpDPT resb 4 ; 8, Far pointer to DPT
14endstruc
15
16
17; Section containing code
18SECTION .text
19
20;--------------------------------------------------------------------
21; MemIdeTransfer_StartWithCommandInAL
22; Parameters:
23; AL: IDE command that was used to start the transfer
24; (all PIO read and write commands including Identify Device)
25; ES:SI: Ptr to normalized data buffer
26; DS:DI: Ptr to DPT (in RAMVARS segment)
27; SS:BP: Ptr to IDEPACK
28; Returns:
29; AH: INT 13h Error Code
30; CX: Number of successfully transferred sectors
31; CF: Cleared if success, Set if error
32; Corrupts registers:
33; AL, BX, DX, SI, ES
34;--------------------------------------------------------------------
35ALIGN JUMP_ALIGN
36MemIdeTransfer_StartWithCommandInAL:
37 push cs ; We push CS here (segment of SAW) and later pop it to DS (reads) or ES (writes)
38
39 ; Initialize MEMPIOVARS
40 xor cx, cx
41 mov [bp+MEMPIOVARS.wWordsDone], cx
42 mov ch, [bp+IDEPACK.bSectorCount]
43 mov [bp+MEMPIOVARS.wWordsLeft], cx
44 mov ch, [di+DPT_ATA.bSetBlock]
45 mov [bp+MEMPIOVARS.wWordsInBlock], cx
46 mov [bp+MEMPIOVARS.fpDPT], di
47 mov [bp+MEMPIOVARS.fpDPT+2], ds
48
49 ; Are we reading or writing?
50 test al, 16 ; Bit 4 is cleared on all the read commands but set on 3 of the 4 write commands
51 jnz SHORT WriteToSectorAccessWindow
52 cmp al, COMMAND_WRITE_MULTIPLE
53 je SHORT WriteToSectorAccessWindow
54 ; Fall to ReadFromSectorAccessWindow
55
56;--------------------------------------------------------------------
57; ReadFromSectorAccessWindow
58; Parameters:
59; Stack: Segment part of ptr to Sector Access Window
60; ES:SI: Normalized ptr to buffer to receive data
61; SS:BP: Ptr to MEMPIOVARS
62; Returns:
63; DS:DI: Ptr to DPT (in RAMVARS segment)
64; AH: BIOS Error code
65; CX: Number of successfully transferred sectors
66; CF: 0 if transfer succesfull
67; 1 if any error
68; Corrupts registers:
69; AL, BX, DX, SI, ES
70;--------------------------------------------------------------------
71ReadFromSectorAccessWindow:
72 pop ds ; CS -> DS
73 mov di, si
74 mov si, JRIDE_SECTOR_ACCESS_WINDOW_OFFSET
75
76 call WaitUntilReadyToTransferNextBlock
77 jc SHORT ReturnWithMemoryIOtransferErrorInAH
78
79 mov cx, [bp+PIOVARS.wWordsInBlock]
80
81ALIGN JUMP_ALIGN
82.ReadNextBlockFromDrive:
83 cmp [bp+PIOVARS.wWordsLeft], cx
84 jbe SHORT .ReadLastBlockFromDrive
85 call ReadSingleBlockFromSectorAccessWindowInDSSItoESDI
86 call WaitUntilReadyToTransferNextBlock
87 jc SHORT ReturnWithMemoryIOtransferErrorInAH
88
89 ; Increment number of successfully read WORDs
90 mov cx, [bp+PIOVARS.wWordsInBlock]
91 sub [bp+PIOVARS.wWordsLeft], cx
92 add [bp+PIOVARS.wWordsDone], cx
93 jmp SHORT .ReadNextBlockFromDrive
94
95ALIGN JUMP_ALIGN
96.ReadLastBlockFromDrive:
97 mov ch, [bp+PIOVARS.wWordsLeft+1] ; Sectors left
98 call ReadSingleBlockFromSectorAccessWindowInDSSItoESDI
99
100 ; Check for errors in last block
101CheckErrorsAfterTransferringLastMemoryMappedBlock:
102 lds di, [bp+MEMPIOVARS.fpDPT] ; DPT now in DS:DI
103 mov bx, TIMEOUT_AND_STATUS_TO_WAIT(TIMEOUT_DRQ, FLG_STATUS_DRDY)
104 call IDEDEVICE%+Wait_PollStatusFlagInBLwithTimeoutInBH
105
106 ; Return number of successfully transferred sectors
107ReturnWithMemoryIOtransferErrorInAH:
108 lds di, [bp+MEMPIOVARS.fpDPT] ; DPT now in DS:DI
109 mov cx, [bp+PIOVARS.wWordsDone]
110 jc SHORT .ConvertTransferredWordsInCXtoSectors
111 add cx, [bp+PIOVARS.wWordsLeft] ; Never sets CF
112.ConvertTransferredWordsInCXtoSectors:
113 xchg cl, ch
114 ret
115
116
117;--------------------------------------------------------------------
118; WriteToSectorAccessWindow
119; Parameters:
120; Stack: Segment part of ptr to Sector Access Window
121; ES:SI: Normalized ptr to buffer containing data
122; SS:BP: Ptr to MEMPIOVARS
123; Returns:
124; DS:DI: Ptr to DPT (in RAMVARS segment)
125; AH: BIOS Error code
126; CX: Number of successfully transferred sectors
127; CF: 0 if transfer succesfull
128; 1 if any error
129; Corrupts registers:
130; AL, BX, DX, SI, ES
131;--------------------------------------------------------------------
132ALIGN JUMP_ALIGN
133WriteToSectorAccessWindow:
134 push es
135 pop ds
136 pop es ; CS -> ES
137 mov di, JRIDE_SECTOR_ACCESS_WINDOW_OFFSET
138
139 ; Always poll when writing first block (IRQs are generated for following blocks)
140 call WaitUntilReadyToTransferNextBlock
141 jc SHORT ReturnWithMemoryIOtransferErrorInAH
142
143 mov cx, [bp+PIOVARS.wWordsInBlock]
144
145ALIGN JUMP_ALIGN
146.WriteNextBlockToDrive:
147 cmp [bp+PIOVARS.wWordsLeft], cx
148 jbe SHORT .WriteLastBlockToDrive
149 call WriteSingleBlockFromDSSIToSectorAccessWindowInESDI
150 call WaitUntilReadyToTransferNextBlock
151 jc SHORT ReturnWithMemoryIOtransferErrorInAH
152
153 ; Increment number of successfully written WORDs
154 mov cx, [bp+PIOVARS.wWordsInBlock]
155 sub [bp+PIOVARS.wWordsLeft], cx
156 add [bp+PIOVARS.wWordsDone], cx
157 jmp SHORT .WriteNextBlockToDrive
158
159ALIGN JUMP_ALIGN
160.WriteLastBlockToDrive:
161 mov ch, [bp+PIOVARS.wWordsLeft+1] ; Sectors left
162%ifndef USE_186
163 mov bx, CheckErrorsAfterTransferringLastMemoryMappedBlock
164 push bx
165%else
166 push CheckErrorsAfterTransferringLastMemoryMappedBlock
167%endif
168 ; Fall to WriteSingleBlockFromDSSIToSectorAccessWindowInESDI
169
170;--------------------------------------------------------------------
171; WriteSingleBlockFromDSSIToSectorAccessWindowInESDI
172; Parameters:
173; CH: Number of sectors in block
174; DS:SI: Normalized ptr to source buffer
175; ES:DI: Ptr to Sector Access Window
176; Returns:
177; CX, DX: Zero
178; SI: Updated
179; Corrupts registers:
180; BX
181;--------------------------------------------------------------------
182ALIGN JUMP_ALIGN
183WriteSingleBlockFromDSSIToSectorAccessWindowInESDI:
184 mov bx, di
185 eMOVZX dx, ch
186 xor cl, cl
187ALIGN JUMP_ALIGN
188.WriteBlock:
189 mov ch, JRIDE_SECTOR_ACCESS_WINDOW_SIZE >> 9
190 rep movsw
191 mov di, bx ; Reset for next sector
192 dec dx
193 jnz SHORT .WriteBlock
194 ret
195
196
197;--------------------------------------------------------------------
198; ReadSingleBlockFromSectorAccessWindowInDSSItoESDI
199; Parameters:
200; CH: Number of sectors in block
201; ES:DI: Normalized ptr to buffer to receive data (destination)
202; DS:SI: Ptr to Sector Access Window (source)
203; Returns:
204; CX, DX: Zero
205; DI: Updated
206; Corrupts registers:
207; BX
208;--------------------------------------------------------------------
209ALIGN JUMP_ALIGN
210ReadSingleBlockFromSectorAccessWindowInDSSItoESDI:
211 mov bx, si
212 eMOVZX dx, ch
213 xor cl, cl
214ALIGN JUMP_ALIGN
215.ReadBlock:
216 mov ch, JRIDE_SECTOR_ACCESS_WINDOW_SIZE >> 9
217 rep movsw
218 mov si, bx ; Reset for next sector
219 dec dx
220 jnz SHORT .ReadBlock
221 ret
222
223
224;--------------------------------------------------------------------
225; WaitUntilReadyToTransferNextBlock
226; Parameters:
227; SS:BP: Ptr to MEMPIOVARS
228; Returns:
229; AH: INT 13h Error Code
230; CF: Cleared if success, Set if error
231; Corrupts registers:
232; AL, BX, CX, DX
233;--------------------------------------------------------------------
234ALIGN JUMP_ALIGN
235WaitUntilReadyToTransferNextBlock:
236 push ds
237 push di
238 lds di, [bp+MEMPIOVARS.fpDPT] ; DPT now in DS:DI
239 call IDEDEVICE%+Wait_IRQorDRQ ; Always polls
240 pop di
241 pop ds
242 ret
243
244
245%if JRIDE_SECTOR_ACCESS_WINDOW_SIZE <> 512
246 %error "JRIDE_SECTOR_ACCESS_WINDOW_SIZE is no longer equal to 512. MemIdeTransfer.asm needs changes."
247%endif
248
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