source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/Serial/SerialCommand.asm@ 204

Last change on this file since 204 was 203, checked in by gregli@…, 13 years ago

Reworked the 'skip detecting the slave if there was no master' code to be more complete (includes configurator drives) and to take into account int13h/25h calls. Some of the changes in my last checkin have been rolled back as a result (they are no longer needed). I did take a byte out of RAMVARS, but there was an alignment byte available for the taking. I also added a perl script for padding and adding the checksum byte to a binary image, which can be invoked manually or with 'make checksum'.
File size: 18.9 KB
RevLine 
[150]1; Project name : XTIDE Universal BIOS
2; Description : Serial Device Command functions.
3
4; Section containing code
5SECTION .text
6
[179]7;--------------- UART Equates -----------------------------
8;
9; Serial Programming References:
10; http://en.wikibooks.org/wiki/Serial_Programming
11;
[181]12
[179]13SerialCommand_UART_base EQU 0
14SerialCommand_UART_transmitByte EQU 0
15SerialCommand_UART_receiveByte EQU 0
16SerialCommand_UART_divisorLow EQU 0
[181]17; Values for UART_divisorLow:
[179]18; 60h = 1200, 30h = 2400, 18h = 4800, 0ch = 9600, 6 = 19200, 3 = 38400, 2 = 57600, 1 = 115200
19
20SerialCommand_UART_divisorLow_startingBaud EQU 030h
21; We support 4 baud rates, starting here going higher and skipping every other baud rate
22; Starting with 30h, that means 30h (1200 baud), 0ch (9600 baud), 3 (38400 baud), and 1 (115200 baud)
23; Note: hardware baud multipliers (2x, 4x) will impact the final baud rate and are not known at this level
24
[181]25SerialCommand_UART_interruptEnable EQU 1
[179]26SerialCommand_UART_divisorHigh EQU 1
27; UART_divisorHigh is zero for all speeds including and above 1200 baud
28
29SerialCommand_UART_interruptIdent EQU 2
30SerialCommand_UART_FIFOControl EQU 2
31
32SerialCommand_UART_lineControl EQU 3
[181]33
[179]34SerialCommand_UART_modemControl EQU 4
35
36SerialCommand_UART_lineStatus EQU 5
37
38SerialCommand_UART_modemStatus EQU 6
39
40SerialCommand_UART_scratch EQU 7
41
42SerialCommand_Protocol_Write EQU 3
43SerialCommand_Protocol_Read EQU 2
44SerialCommand_Protocol_Inquire EQU 0
45SerialCommand_Protocol_Header EQU 0a0h
[181]46
[150]47;--------------------------------------------------------------------
[179]48; SerialCommand_OutputWithParameters
[150]49; Parameters:
[179]50; BH: Non-zero if 48-bit addressing used
51; (ignored at present as 48-bit addressing is not supported)
52; BL: IDE Status Register bit to poll after command
53; (ignored at present, since there is no IDE status register to poll)
54; ES:SI: Ptr to buffer (for data transfer commands)
55; DS:DI: Ptr to DPT (in RAMVARS segment)
56; SS:BP: Ptr to IDEREGS_AND_INTPACK
[150]57; Returns:
58; AH: INT 13h Error Code
59; CF: Cleared if success, Set if error
60; Corrupts registers:
[179]61; AL, BX, CX, DX, (ES:SI for data transfer commands)
[150]62;--------------------------------------------------------------------
63ALIGN JUMP_ALIGN
[179]64SerialCommand_OutputWithParameters:
[181]65
[179]66 mov ah,(SerialCommand_Protocol_Header | SerialCommand_Protocol_Read)
[181]67
[179]68 mov al,[bp+IDEPACK.bCommand]
[150]69
[179]70 cmp al,20h ; Read Sectors IDE command
71 jz .readOrWrite
72 inc ah ; now SerialCommand_Protocol_Write
73 cmp al,30h ; Write Sectors IDE command
74 jz .readOrWrite
[181]75
[179]76; all other commands return success
77; including function 0ech which should return drive information, this is handled with the identify functions
78 xor ah,ah ; also clears carry
79 ret
[181]80
81.readOrWrite:
[179]82 mov [bp+IDEPACK.bFeatures],ah ; store protocol command
[181]83
84 mov dl, byte [di+DPT.bSerialPortAndBaud]
85
[179]86; fall-through
[150]87
88;--------------------------------------------------------------------
[179]89; SerialCommand_OutputWithParameters_DeviceInDL
[150]90; Parameters:
[181]91; AH: Protocol Command
[179]92; DL: Packed I/O port and baud rate
[150]93; ES:SI: Ptr to buffer (for data transfer commands)
94; SS:BP: Ptr to IDEREGS_AND_INTPACK
95; Returns:
96; AH: INT 13h Error Code
97; CF: Cleared if success, Set if error
98; Corrupts registers:
99; AL, BX, CX, DX, (ES:SI for data transfer commands)
[181]100;--------------------------------------------------------------------
[179]101SerialCommand_OutputWithParameters_DeviceInDL:
[181]102
[179]103 push si
104 push di
105 push bp
106 push es
107
[181]108;
[179]109; Unpack I/O port and baud from DPT
110; Port to DX more or less for the remainder of the routine
111; Baud in CH until UART initialization is complete
112;
113 mov cl, dl
[181]114
[199]115 and cl, DEVICE_SERIAL_PACKEDPORTANDBAUD_BAUDMASK
[179]116 shl cl, 1
117 mov ch, SerialCommand_UART_divisorLow_startingBaud
118 shr ch, cl
119 adc ch, 0
120
[199]121 and dl, DEVICE_SERIAL_PACKEDPORTANDBAUD_PORTMASK
[181]122 mov dh, 0
[196]123 shl dx, 1 ; port offset already x4, needs one more shift to be x8
[199]124 add dx, DEVICE_SERIAL_PACKEDPORTANDBAUD_STARTINGPORT
[179]125
126;
127; Buffer is referenced through ES:DI throughout, since we need to store faster than we read
[181]128;
[179]129 mov di,si
130
131 mov al,[bp+IDEPACK.bSectorCount]
132
133;
134; Command byte and sector count live at the top of the stack, pop/push are used to access
[181]135;
[179]136 push ax
137
[181]138; cld ; Shouldn't be needed. DF has already been cleared (line 24, Int13h.asm)
139
[179]140;----------------------------------------------------------------------
141;
142; Initialize UART
143;
[181]144; We do this each time since DOS (at boot) or another program may have
[179]145; decided to reprogram the UART
146;
147 push dx
[181]148
[179]149 mov al,83h
150 add dl,SerialCommand_UART_lineControl
151 out dx,al
152
153 mov al,ch
154 pop dx ; divisor low
155 out dx,al
156
157 xor ax,ax
158 inc dx ; divisor high
159 push dx
160 out dx,al
161
162 mov al,047h
163 inc dx ; fifo
[181]164 out dx,al
[179]165
166 mov al,03h
167 inc dx ; linecontrol
168 out dx,al
169
170 mov al,0bh
171 inc dx ; modemcontrol
172 out dx,al
173
174 pop dx ; base, interrupts disabled
175 xor ax,ax
176 out dx,al
177 dec dx
178
179;----------------------------------------------------------------------
180;
181; Send Command
182;
183; Sends first six bytes of IDEREGS_AND_INTPACK as the command
184;
185 call Registers_NormalizeESDI
186
187 push es ; save off real buffer location
188 push di
[181]189
190 mov di,bp ; point to IDEREGS for command dispatch;
[179]191 push ss
192 pop es
193
194 xor si,si ; initialize checksum for write
[181]195 dec si
[179]196 mov bp,si
197
198 mov bl,03h ; writing 3 words
[181]199
[179]200 call SerialCommand_WriteProtocol
201
202 pop di ; restore real buffer location
203 pop es
204
205 pop ax ; load command byte (done before call to .nextSector on subsequent iterations)
206 push ax
207
208;
209; Top of the read/write loop, one iteration per sector
[181]210;
[179]211.nextSector:
212 xor si,si ; initialize checksum for read or write
213 dec si
214 mov bp,si
215
216 mov bx,0100h
[181]217
[179]218 shr ah,1 ; command byte, are we doing a write?
219 jnc .readSector
220 call SerialCommand_WriteProtocol
[181]221
[179]222 xor bx,bx
223
224.readSector:
225 mov cx,bx
226 inc cx
[181]227
[179]228 mov bl,dl ; setup bl with proper values for read loop (bh comes later)
229
230;----------------------------------------------------------------------
231;
232; Timeout
233;
234; During read, we first poll in a tight loop, interrupts off, for the next character to come in
235; If that loop completes, then we assume there is a long delay involved, turn interrupts back on
236; and wait for a given number of timer ticks to pass.
237;
238; To save code space, we use the contents of DL to decide which byte in the word to return for reading.
239;
240.readTimeout:
241 push cx
242 xor cx,cx
[181]243.readTimeoutLoop:
[179]244 push dx
245 or dl,SerialCommand_UART_lineStatus
246 in al,dx
247 pop dx
248 shr al,1
249 jc .readTimeoutComplete
250 loop .readTimeoutLoop
251 sti
252 mov bh,1
253 call SerialCommand_WaitAndPoll_Init
[181]254 cli
[179]255.readTimeoutComplete:
256 mov bh,bl
257 or bh,SerialCommand_UART_lineStatus
[181]258
[179]259 pop cx
260 test dl,1
261 jz .readByte1Ready
262 jmp .readByte2Ready
263
264;----------------------------------------------------------------------------
265;
266; Read Block (without interrupts, used when there is a FIFO, high speed)
267;
[181]268; NOTE: This loop is very time sensitive. Literally, another instruction
[179]269; cannot be inserted into this loop without us falling behind at high
[181]270; speed (460.8K baud) on a 4.77Mhz 8088, making it hard to receive
[179]271; a full 512 byte block.
272;
[181]273.readLoop:
274 stosw ; store word in caller's data buffer
275
[179]276 add bp, ax ; update Fletcher's checksum
277 adc bp, 0
278 add si, bp
279 adc si, 0
280
[181]281 mov dl,bh
282 in al,dx
[179]283 shr al,1 ; data ready (byte 1)?
[181]284 mov dl,bl ; get ready to read data
[179]285 jnc .readTimeout ; nope not ready, update timeouts
[181]286
287;
[179]288; Entry point after initial timeout. We enter here so that the checksum word
289; is not stored (and is left in AX after the loop is complete).
[181]290;
291.readByte1Ready:
[179]292 in al, dx ; read data byte 1
293
294 mov ah, al ; store byte in ah for now
[181]295
[179]296;
[181]297; note the placement of this reset of dl to bh, and that it is
298; before the return, which is assymetric with where this is done
299; above for byte 1. The value of dl is used by the timeout routine
300; to know which byte to return to (.read_byte1_ready or
[179]301; .read_byte2_ready)
302;
[181]303 mov dl,bh
304
[179]305 in al,dx
306 shr al,1 ; data ready (byte 2)?
307 jnc .readTimeout
[181]308.readByte2Ready:
309 mov dl,bl
[179]310 in al, dx ; read data byte 2
311
312 xchg al, ah ; ah was holding byte 1, reverse byte order
[181]313
[179]314 loop .readLoop
315
[181]316 sti ; interrupts back on ASAP, if we turned them off
317
[179]318;
319; Compare checksums
[181]320;
[179]321 xor bp,si
322 cmp ax,bp
323 jnz SerialCommand_OutputWithParameters_Error
324
[181]325
[179]326;----------------------------------------------------------------------
[181]327;
[179]328; Clear read buffer
329;
330; In case there are extra characters or an error in the FIFO, clear it out.
[181]331; In theory the initialization of the UART registers above should have
[179]332; taken care of this, but I have seen cases where this is not true.
333;
334.clearBuffer:
[181]335 mov dl,bh
[179]336 in al,dx
[181]337 mov dl,bl
[179]338 test al,08fh
339 jz .clearBufferComplete
340 shr al,1
[181]341 in al,dx
[179]342 jc .clearBuffer ; note CF from shr above
343 jmp SerialCommand_OutputWithParameters_Error
[181]344
345.clearBufferComplete:
[179]346 pop ax ; sector count and command byte
347 dec al ; decrememnt sector count
348 push ax ; save
349 jz SerialCommand_OutputWithParameters_ReturnCodeInALCF ; CF clear from .clearBuffer test above
[181]350
[179]351 cli ; interrupts back off for ACK byte to host
352 ; (host could start sending data immediately)
353 out dx,al ; ACK with next sector number
[181]354
[179]355 jmp .nextSector ; all is well, time for next sector
356
357;---------------------------------------------------------------------------
358;
359; Cleanup, error reporting, and exit
360;
[181]361
362;
[179]363; Used in situations where a call is underway, such as with SerialCommand_WaitAndPoll
[181]364;
[179]365SerialCommand_OutputWithParameters_ErrorAndPop2Words:
366 pop ax
367 pop ax
368
[181]369SerialCommand_OutputWithParameters_Error:
370 stc
[179]371 mov al,1
372
[181]373SerialCommand_OutputWithParameters_ReturnCodeInALCF:
374 sti
[179]375 mov ah,al
376
377 pop bp ; recover ax from stack, throw away
378
379 pop es
380 pop bp
381 pop di
382 pop si
383
384 ret
385
[150]386;--------------------------------------------------------------------
[179]387; SerialCommand_WaitAndPoll
388;
389; Parameters:
390; BH: UART_LineStatus bit to test (20h for write, or 1h for read)
391; DX: Port address (OK if already incremented to UART_lineStatus)
392; Stack: 2 words on the stack below the command/count word
393; Returns:
394; Returns when desired UART_LineStatus bit is cleared
395; Jumps directly to error exit if timeout elapses (and cleans up stack)
[181]396; Corrupts registers:
[179]397; CX, flags
398;--------------------------------------------------------------------
399
400SerialCommand_WaitAndPoll_SoftDelayTicks EQU 20
401
[181]402ALIGN JUMP_ALIGN
[179]403SerialCommand_WaitAndPoll_Init:
404 mov cl,SerialCommand_WaitAndPoll_SoftDelayTicks
405 call Timer_InitializeTimeoutWithTicksInCL
406; fall-through
[181]407
[179]408SerialCommand_WaitAndPoll:
409 call Timer_SetCFifTimeout
410 jc SerialCommand_OutputWithParameters_ErrorAndPop2Words
411 push dx
412 push ax
413 or dl,SerialCommand_UART_lineStatus
414 in al,dx
415 test al,bh
416 pop ax
417 pop dx
418 jz SerialCommand_WaitAndPoll
419; fall-through
[181]420
421SerialCommand_WaitAndPoll_Done:
[179]422 ret
423
424;--------------------------------------------------------------------
425; SerialCommand_WriteProtocol
426;
427; Parameters:
428; ES:DI: Ptr to buffer
429; BL: Words to write (1-255, or 0=256)
430; BP/SI: Initialized for Checksum (-1 in each)
431; DX: I/O Port
432; Returns:
433; BP/SI: Checksum for written bytes, compared against ACK from server in .readLoop
434; Corrupts registers:
435; AX, BX, CX, DI
436;--------------------------------------------------------------------
[150]437ALIGN JUMP_ALIGN
[179]438SerialCommand_WriteProtocol:
439 mov bh,20h
[181]440
[179]441.writeLoop:
442 test bh,1
443 jnz SerialCommand_WaitAndPoll_Done
[181]444
[179]445 mov ax,[es:di] ; fetch next word
446 inc di
447 inc di
[181]448
[179]449 add bp,ax ; update checksum
450 adc bp,0
451 add si,bp
452 adc si,0
[150]453
[179]454.writeLoopChecksum:
455 call SerialCommand_WaitAndPoll_Init
[181]456
[179]457 out dx,al ; output first byte
[150]458
[179]459 call SerialCommand_WaitAndPoll
[181]460
[179]461 mov al,ah ; output second byte
462 out dx,al
463
464 dec bl
465 jnz .writeLoop
[181]466
[179]467 inc bh
[181]468
[179]469 mov ax,bp ; merge checksum for possible write (last loop)
[181]470 xor ax,si
471
[179]472 jmp .writeLoopChecksum
473
474
475;--------------------------------------------------------------------
476; SerialCommand_IdentifyDeviceToBufferInESSIwithDriveSelectByteInBH
477; Parameters:
478; BH: Drive Select byte for Drive and Head Select Register
479; DS: Segment to RAMVARS
480; ES:SI: Ptr to buffer to receive 512-byte IDE Information
481; CS:BP: Ptr to IDEVARS
482; Returns:
483; AH: INT 13h Error Code
[203]484; NOTE: Not set (or checked) during drive detection
[179]485; CF: Cleared if success, Set if error
486; Corrupts registers:
487; AL, BL, CX, DX, SI, DI, ES
488;--------------------------------------------------------------------
489ALIGN JUMP_ALIGN
490SerialCommand_IdentifyDeviceToBufferInESSIwithDriveSelectByteInBH:
[203]491;
492; To improve boot time, we do our best to avoid looking for slave serial drives when we already know the results
493; from the looking for a master. This is particuarly true when doing a COM port scan, as we will end up running
494; through all the COM ports and baud rates a second time.
495;
496; But drive detection isn't the only case - we also need to get the right drive when called on int13h/25h.
497;
498; The decision tree:
499;
500; Master:
501; bSerialPackedPortAndBaud Non-Zero: -> Continue with bSerialPackedAndBaud (1)
502; bSerialPackedPortAndBaud Zero:
503; bLastSerial Zero: -> Scan (2)
504; bLastSerial Non-Zero: -> Continue with bLastSerial (3)
505;
506; Slave:
507; bSerialPackedPortAndBaud Non-Zero:
508; bLastSerial Zero: -> Error - Not Found (4)
509; bLastSerial Non-Zero: -> Continue with bSerialPackedAndBaud (5)
510; bSerialPackedPortAndBaud Zero:
511; bLastSerial Zero: -> Error - Not Found (4)
512; bLastSerial Non-Zero: -> Continue with bLastSerial (6)
513;
514; (1) This was a port/baud that was explicilty set with the configurator. In the drive detection case, as this
515; is the Master, we are checking out a new controller, and so don't care about the value of bLastSerial.
516; And as with the int13h/25h case, we just go off and get the needed information using the user's setting.
517; (2) We are using the special .ideVarsSerialAuto strucutre. During drive detection, we would only be here
518; if bLastSerial is zero (since we only scan if no explicit drives are set), so we go off to scan.
519; (3) We are using the special .ideVarsSerialAuto strucutre. We won't get here during drive detection, but
520; we might get here on an int13h/25h call. If we have scanned COM drives, they are the ONLY serial drives
521; in use, and so bLastSerial will reflect the port/baud setting for the scanned COM drives.
522; (4) No master has been found yet, therefore no slave should be found. Avoiding the slave reduces boot time,
523; especially in the full COM port scan case. Note that this is different from the hardware IDE, where we
524; will scan for a slave even if a master is not present. Note that if ANY master had been previously found,
525; we will do the slave scan, which isn't harmful, it just wates time. But the most common case (by a wide
526; margin) will be just one serial controller.
527; (5) A COM port scan for a master had been previously completed, and a drive was found. In a multiple serial
528; controller scenario being called with int13h/25h, we need to use the value in bSerialPackedPortAndBaud
529; to make sure we get the proper drive.
530; (6) A COM port scan for a master had been previously completed, and a drive was found. We would only get here
531; if no serial drive was explicitly set by the user in the configurator or that drive had not been found.
532; Instead of performing the full COM port scan for the slave, use the port/baud value stored during the
533; master scan.
534;
535 mov dl,[cs:bp+IDEVARS.bSerialPackedPortAndBaud]
536 mov al, byte [RAMVARS.xlateVars+XLATEVARS.bLastSerial]
537
538 test bh, FLG_DRVNHEAD_DRV
539 jz .master
[179]540
[203]541 test al,al ; Take care of the case that is different between master and slave.
542 jz .error ; Because we do this here, the jz after the "or" below will not be taken
543
544; fall-through
545.master:
[196]546 test dl,dl
[203]547 jnz .identifyDeviceInDL
[179]548
[203]549 or dl,al ; Move bLast into position in dl, as well as test for zero
550 jz .scanSerial
[199]551
[179]552; fall-through
[203]553.identifyDeviceInDL:
[179]554
555 push bp ; setup fake IDEREGS_AND_INTPACK
556
557 push dx
558
559 mov cl,1 ; 1 sector to move
560 push cx
561
562 mov bl,0a0h ; protocol command to ah and onto stack with bh
563 mov ah,bl
[181]564
[179]565 push bx
566
567 mov bp,sp
568 call SerialCommand_OutputWithParameters_DeviceInDL
569
570 pop bx
[181]571
572 pop cx
[179]573 pop dx
574
575 pop bp
[203]576;
577; place packed port/baud in RAMVARS, read by FinalizeDPT and DetectDrives
578;
579; Note that this will be set during an int13h/25h call as well. Which is OK since it is only used (at the
580; top of this routine) for drives found during a COM scan, and we only COM scan if there were no other
581; COM drives found. So we will only reaffirm the port/baud for the one COM port/baud that has a drive.
582;
583 jc .notFound ; only store bLastSerial if success
584 mov byte [RAMVARS.xlateVars+XLATEVARS.bLastSerial], dl
[179]585
[203]586.notFound:
[179]587 ret
588
589;----------------------------------------------------------------------
590;
591; SerialCommand_AutoSerial
592;
593; When the SerialAuto IDEVARS entry is used, scans the COM ports on the machine for a possible serial connection.
[181]594;
595
[203]596.scanPortAddresses: db DEVICE_SERIAL_COM7 >> 2
597 db DEVICE_SERIAL_COM6 >> 2
598 db DEVICE_SERIAL_COM5 >> 2
599 db DEVICE_SERIAL_COM4 >> 2
600 db DEVICE_SERIAL_COM3 >> 2
601 db DEVICE_SERIAL_COM2 >> 2
602 db DEVICE_SERIAL_COM1 >> 2
603 db 0
[179]604
[181]605ALIGN JUMP_ALIGN
[203]606.scanSerial:
607 mov di,.scanPortAddresses-1
[181]608
[179]609.nextPort:
610 inc di ; load next port address
611 mov dl,[cs:di]
[181]612
[179]613 mov dh,0 ; shift from one byte to two
[181]614 eSHL_IM dx, 2
[203]615 jz .error
[179]616
617;
618; Test for COM port presence, write to and read from registers
[181]619;
620 push dx
[179]621 add dl,SerialCommand_UART_lineControl
622 mov al, 09ah
623 out dx, al
624 in al, dx
625 pop dx
626 cmp al, 09ah
[181]627 jnz .nextPort
[179]628
629 mov al, 0ch
630 out dx, al
631 in al, dx
632 cmp al, 0ch
633 jnz .nextPort
634
635;
636; Pack into dl, baud rate starts at 0
[181]637;
[199]638 add dx,-(DEVICE_SERIAL_PACKEDPORTANDBAUD_STARTINGPORT)
639 shr dx,1 ; dh is zero at this point, and will be sent to the server,
640 ; so we know this is an auto detect
[181]641
[179]642 jmp .testFirstBaud
643
644;
645; Walk through 4 possible baud rates
[181]646;
647.nextBaud:
[179]648 inc dx
649 test dl,3
650 jz .nextPort
[181]651
652.testFirstBaud:
[203]653 call .identifyDeviceInDL
[179]654 jc .nextBaud
655
656 ret
[181]657
[203]658.error:
[181]659 stc
[203]660 ; mov ah,1 ; setting the error code is unnecessary as this path can only be taken during
661 ; drive detection, and drive detection works off CF and does not check AH
662 ret
[179]663
[203]664
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