source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeTransfer.asm@ 541

Last change on this file since 541 was 539, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

  • Carry flag is no longer cleared when segment overflow during pointer normalization.
File size: 11.8 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : IDE Device transfer functions.
3
4;
5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
7;
8; This program is free software; you can redistribute it and/or modify
9; it under the terms of the GNU General Public License as published by
10; the Free Software Foundation; either version 2 of the License, or
11; (at your option) any later version.
12;
13; This program is distributed in the hope that it will be useful,
14; but WITHOUT ANY WARRANTY; without even the implied warranty of
15; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16; GNU General Public License for more details.
17; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
18;
19
20; Structure containing variables for PIO transfer functions.
21; This struct must not be larger than IDEPACK without INTPACK.
22struc PIOVARS ; Must not be larger than 9 bytes! See IDEPACK in RamVars.inc.
23 .wDataPort resb 2 ; 0-1, IDE Data Port
24 .fnXfer resb 2 ; 2-3, Offset to transfer function
25 .wSectorsInBlock resb 2 ; 4-5, Block size in sectors
26 .bSectorsLeft resb 1 ; 6, Sectors left to transfer
27 resb 1 ; 7, IDEPACK.bDeviceControl
28 .bSectorsDone resb 1 ; 8, Number of sectors xferred
29endstruc
30
31
32; Section containing code
33SECTION .text
34
35;--------------------------------------------------------------------
36; IdeTransfer_StartWithCommandInAL
37; Parameters:
38; AL: IDE command that was used to start the transfer
39; (all PIO read and write commands including Identify Device)
40; ES:SI: Ptr to data buffer
41; DS:DI: Ptr to DPT (in RAMVARS segment)
42; SS:BP: Ptr to IDEPACK
43; Returns:
44; AH: INT 13h Error Code
45; CX: Number of successfully transferred sectors
46; CF: Cleared if success, Set if error
47; Corrupts registers:
48; AL, BX, DX, SI, ES
49;--------------------------------------------------------------------
50ALIGN JUMP_ALIGN
51IdeTransfer_StartWithCommandInAL:
52 ; Are we reading or writing?
53 test al, 16 ; Bit 4 is cleared on all the read commands but set on 3 of the 4 write commands
54 mov ah, [bp+IDEPACK.bSectorCount]
55 jnz SHORT WriteToDrive
56 cmp al, COMMAND_WRITE_MULTIPLE
57 je SHORT WriteToDrive
58 ; Fall to ReadFromDrive
59
60;--------------------------------------------------------------------
61; ReadFromDrive
62; Parameters:
63; AH: Number of sectors to transfer (1...128)
64; ES:SI: Ptr to buffer to receive data
65; DS:DI: Ptr to DPT (in RAMVARS segment)
66; SS:BP: Ptr to PIOVARS
67; Returns:
68; DS:DI: Ptr to DPT (in RAMVARS segment)
69; AH: BIOS Error code
70; CX: Number of successfully transferred sectors
71; CF: 0 if transfer successful
72; 1 if any error
73; Corrupts registers:
74; AL, BX, DX, SI, ES
75;--------------------------------------------------------------------
76ReadFromDrive:
77 ; Prepare to read data to ESSI
78 mov bx, g_rgfnPioRead
79 call InitializePiovarsInSSBPwithSectorCountInAH
80%ifdef USE_AT
81 jc SHORT ReturnWithTransferErrorInAH
82%endif
83
84 ; Wait until drive is ready to transfer
85 call IdeWait_IRQorDRQ ; Wait until ready to transfer
86 jc SHORT ReturnWithTransferErrorInAH
87 xchg si, di ; ES:DI now points buffer
88
89 mov cx, [bp+PIOVARS.wSectorsInBlock] ; Max 128
90
91ALIGN JUMP_ALIGN
92.ReadNextBlockFromDrive:
93 mov dx, [bp+PIOVARS.wDataPort]
94 cmp [bp+PIOVARS.bSectorsLeft], cl
95 jbe SHORT .ReadLastBlockFromDrive
96 call [bp+PIOVARS.fnXfer]
97
98 ; Wait until ready for next block and check for errors
99 xchg di, si ; DS:DI now points DPT
100 call IdeWait_IRQorDRQ ; Wait until ready to transfer
101 jc SHORT ReturnWithTransferErrorInAH
102 xchg si, di ; ES:DI now points buffer
103
104 ; Increment number of successfully read sectors
105 mov cx, [bp+PIOVARS.wSectorsInBlock]
106 sub [bp+PIOVARS.bSectorsLeft], cl
107 add [bp+PIOVARS.bSectorsDone], cl
108 jmp SHORT .ReadNextBlockFromDrive
109
110ALIGN JUMP_ALIGN
111.ReadLastBlockFromDrive:
112 mov cl, [bp+PIOVARS.bSectorsLeft] ; CH is already zero
113 push cx
114 call [bp+PIOVARS.fnXfer] ; Transfer possibly partial block
115
116 ; Check for errors in last block
117 mov di, si ; DS:DI now points DPT
118CheckErrorsAfterTransferringLastBlock:
119 mov bx, TIMEOUT_AND_STATUS_TO_WAIT(TIMEOUT_DRQ, FLG_STATUS_BSY)
120 call IdeWait_PollStatusFlagInBLwithTimeoutInBH
121 pop cx ; [bp+PIOVARS.bSectorsLeft]
122 jc SHORT ReturnWithTransferErrorInAH
123
124 ; All sectors successfully transferred
125 add cx, [bp+PIOVARS.bSectorsDone] ; Never sets CF
126 ret
127
128 ; Return number of successfully read sectors
129ReturnWithTransferErrorInAH:
130%ifdef USE_386
131 movzx cx, [bp+PIOVARS.bSectorsDone]
132%else
133 mov cl, [bp+PIOVARS.bSectorsDone]
134 mov ch, 0 ; Preserve CF
135%endif
136 ret
137
138
139;--------------------------------------------------------------------
140; WriteToDrive
141; Parameters:
142; AH: Number of sectors to transfer (1...128)
143; DS:DI: Ptr to DPT (in RAMVARS segment)
144; ES:SI: Ptr to buffer containing data
145; SS:BP: Ptr to PIOVARS
146; Returns:
147; AH: BIOS Error code
148; CX: Number of successfully transferred sectors
149; CF: 0 if transfer successful
150; 1 if any error
151; Corrupts registers:
152; AL, BX, DX, SI, ES
153;--------------------------------------------------------------------
154ALIGN JUMP_ALIGN
155WriteToDrive:
156 ; Prepare to write data from ESSI
157 mov bx, g_rgfnPioWrite
158 call InitializePiovarsInSSBPwithSectorCountInAH
159%ifdef USE_AT
160 jc SHORT ReturnWithTransferErrorInAH
161%endif
162
163 ; Always poll when writing first block (IRQs are generated for following blocks)
164 mov bx, TIMEOUT_AND_STATUS_TO_WAIT(TIMEOUT_DRQ, FLG_STATUS_DRQ)
165 call IdeWait_PollStatusFlagInBLwithTimeoutInBH
166 jc SHORT ReturnWithTransferErrorInAH
167
168 mov cx, [bp+PIOVARS.wSectorsInBlock] ; Max 128
169
170ALIGN JUMP_ALIGN
171.WriteNextBlockToDrive:
172 mov dx, [bp+PIOVARS.wDataPort]
173 cmp [bp+PIOVARS.bSectorsLeft], cl
174 jbe SHORT .WriteLastBlockToDrive
175 call [bp+PIOVARS.fnXfer]
176
177 ; Wait until ready for next block and check for errors
178 call IdeWait_IRQorDRQ ; Wait until ready to transfer
179 jc SHORT ReturnWithTransferErrorInAH
180
181 ; Increment number of successfully written sectors
182 mov cx, [bp+PIOVARS.wSectorsInBlock]
183 sub [bp+PIOVARS.bSectorsLeft], cl
184 add [bp+PIOVARS.bSectorsDone], cl
185 jmp SHORT .WriteNextBlockToDrive
186
187ALIGN JUMP_ALIGN
188.WriteLastBlockToDrive:
189 mov cl, [bp+PIOVARS.bSectorsLeft] ; CH is already zero
190 push cx
191%ifdef USE_186
192 push CheckErrorsAfterTransferringLastBlock
193 jmp [bp+PIOVARS.fnXfer] ; Transfer possibly partial block
194%else
195 call [bp+PIOVARS.fnXfer] ; Transfer possibly partial block
196 jmp SHORT CheckErrorsAfterTransferringLastBlock
197%endif
198
199
200;--------------------------------------------------------------------
201; InitializePiovarsInSSBPwithSectorCountInAH
202; Parameters:
203; AH: Number of sectors to transfer (1...128)
204; BX: Offset to transfer function lookup table
205; DS:DI: Ptr to DPT (in RAMVARS segment)
206; ES:SI: Ptr to data buffer
207; SS:BP: Ptr to PIOVARS
208; Returns:
209; ES:SI: Normalized pointer
210; AH: INT 13h Error Code (only when CF set)
211; CF: Set of failed to normalize pointer (segment overflow)
212; Cleared if success
213; Corrupts registers:
214; AL, BX, DX
215;--------------------------------------------------------------------
216ALIGN JUMP_ALIGN
217InitializePiovarsInSSBPwithSectorCountInAH:
218 ; Store sizes and Data Port
219 mov [bp+PIOVARS.bSectorsLeft], ah
220%ifdef USE_AT
221 xchg dx, ax
222%endif
223 mov ax, [di+DPT.wBasePort]
224 mov [bp+PIOVARS.wDataPort], ax
225 eMOVZX ax, [di+DPT_ATA.bBlockSize]
226 mov [bp+PIOVARS.wSectorsInBlock], ax
227 mov [bp+PIOVARS.bSectorsDone], ah ; Zero
228
229 ; Get transfer function based on bus type
230 xchg ax, bx ; Lookup table offset to AX
231 mov bl, [di+DPT_ATA.bDevice]
232%ifdef MODULE_8BIT_IDE_ADVANCED
233 mov dl, bl
234%endif
235 add bx, ax
236 mov ax, [cs:bx] ; Load offset to transfer function
237 mov [bp+PIOVARS.fnXfer], ax
238
239 ; Normalize pointer for PIO-transfers and convert to physical address for DMA transfers
240%ifdef MODULE_8BIT_IDE_ADVANCED
241 cmp dl, DEVICE_8BIT_XTCF_DMA
242 jb SHORT IdeTransfer_NormalizePointerInESSI
243
244 ; Convert ES:SI to physical address
245%ifdef USE_186 ; Bytes EU Cycles(286)
246 mov ax, es ; 2 2
247 rol ax, 4 ; 3 9
248 mov dx, ax ; 2 2
249 and ax, BYTE 0Fh; 3 3
250 xor dx, ax ; 2 2
251 add si, dx ; 2 2
252 adc al, ah ; 2 2
253 mov es, ax ; 2 2
254 ;------------------------------------
255 ; 18 24
256%else ; 808x
257
258%if 0
259 ; Bytes EU Cycles(808x)
260 mov al, 4 ; 2 4
261 mov dx, es ; 2 2
262 xchg cx, ax ; 1 3
263 rol dx, cl ; 2 24
264 mov cx, dx ; 2 2
265 xchg cx, ax ; 1 3
266 and ax, BYTE 0Fh; 3 4
267 xor dx, ax ; 2 3
268 add si, dx ; 2 3
269 adc al, ah ; 2 3
270 mov es, ax ; 2 2
271 ;------------------------------------
272 ; 21 53
273;
274; Judging by the Execution Unit cycle count the above block of code is
275; apparently slower. However, the shifts and rotates in the block below
276; execute faster than the Bus Interface Unit on an 8088 can fetch them,
277; thus causing the EU to starve. The difference in true execution speed
278; (if any) might not be worth the extra 5 bytes.
279; In other words, we could use a real world test here.
280;
281%endif ; 0
282 ; Bytes EU Cycles(808x/286)
283 xor dx, dx ; 2 3/2
284 mov ax, es ; 2 2/2
285%rep 4
286 shl ax, 1 ; 8 8/8
287 rcl dx, 1 ; 8 8/8
288%endrep
289 add si, ax ; 2 3/2
290 adc dl, dh ; 2 3/2
291 mov es, dx ; 2 2/2
292 ;------------------------------------
293%endif ; 26 29/26
294 clc
295 ret
296%endif ; MODULE_8BIT_IDE_ADVANCED
297 ; Fall to IdeTransfer_NormalizePointerInESSI if no MODULE_8BIT_IDE
298
299
300;--------------------------------------------------------------------
301; IdeTransfer_NormalizePointerInESSI
302; Parameters:
303; DH: Number of sectors to transfer (when USE_AT defined)
304; ES:SI: Ptr to be normalized
305; Returns:
306; ES:SI: Normalized pointer (SI = 0...15)
307; AH: INT 13h Error Code (only when CF set)
308; CF: Set of failed to normalize pointer (segment overflow)
309; Cleared if success
310; Corrupts registers:
311; AX, DX
312;--------------------------------------------------------------------
313IdeTransfer_NormalizePointerInESSI:
314; Normalization can cause segment overflow if it is done when not needed
315; (I don't know if any software calls with such seg:off address).
316; This does not apply to XT systems since nothing will write to main BIOS ROM.
317; On AT systems things are quite different, even in protected mode the address
318; is passed in seg:offset form and HMA is accessible in real mode.
319%ifdef USE_AT
320 xor dl, dl
321 shl dx, 1
322 dec dx ; Prevents normalization when bytes + offset will be zero
323 add dx, si
324 jc SHORT .NormalizationRequired
325 ret
326.NormalizationRequired:
327%endif ; USE_AT
328
329 NORMALIZE_FAR_POINTER es, si, ax, dx
330%ifdef USE_AT ; CF is always clear for XT builds
331 jc SHORT .SegmentOverflow
332 ret
333.SegmentOverflow:
334 mov ah, RET_HD_INVALID
335%endif
336 ret
337
338
339
340; Lookup tables to get transfer function based on bus type
341ALIGN WORD_ALIGN
342g_rgfnPioRead:
343 dw IdePioBlock_ReadFrom16bitDataPort ; 0, DEVICE_16BIT_ATA
344 dw IdePioBlock_ReadFrom32bitDataPort ; 1, DEVICE_32BIT_ATA
345%ifdef MODULE_8BIT_IDE
346 dw IdePioBlock_ReadFrom8bitDataPort ; 2, DEVICE_8BIT_ATA
347 dw IdePioBlock_ReadFromXtideRev1 ; 3, DEVICE_8BIT_XTIDE_REV1
348 dw IdePioBlock_ReadFromXtideRev2 ; 4, DEVICE_8BIT_XTIDE_REV2
349%ifdef MODULE_8BIT_IDE_ADVANCED
350 dw IdePioBlock_ReadFrom8bitDataPort ; 5, DEVICE_8BIT_XTCF_PIO8
351 dw IdeDmaBlock_ReadFromXTCF ; 6, DEVICE_8BIT_XTCF_DMA
352%endif
353%endif
354
355
356g_rgfnPioWrite:
357 dw IdePioBlock_WriteTo16bitDataPort ; 0, DEVICE_16BIT_ATA
358 dw IdePioBlock_WriteTo32bitDataPort ; 1, DEVICE_32BIT_ATA
359%ifdef MODULE_8BIT_IDE
360 dw IdePioBlock_WriteTo8bitDataPort ; 2, DEVICE_8BIT_ATA
361 dw IdePioBlock_WriteToXtideRev1 ; 3, DEVICE_8BIT_XTIDE_REV1
362 dw IdePioBlock_WriteToXtideRev2 ; 4, DEVICE_8BIT_XTIDE_REV2
363%ifdef MODULE_8BIT_IDE_ADVANCED
364 dw IdePioBlock_WriteTo8bitDataPort ; 5, DEVICE_8BIT_XTCF_PIO8
365 dw IdeDmaBlock_WriteToXTCF ; 6, DEVICE_8BIT_XTCF_DMA
366%endif
367%endif
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