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DRIVEIO.ASM@ 45

Last change on this file since 45 was 43, checked in by Ben Rietbroek, 12 years ago

BSS Corruption Problem located (auxdebug on) [2012-02-21]

WARNING!!

All commits upto and including the commit of [2012-05-13] contain
a severe bug!! Building from these sources and then disabling
the 'force LBA' feature while also using the drive-letter feature or
editing the label can DESTROY THE MBR on ALL ATTACHED DISKS!!
DO NOT DISABLE 'FORCE LBA USAGE' WHEN BUILT FROM THE THESE COMMITS!!

Problem

o Function with Xrefs goes out-of-bounds because hideparttable is too small

Has only 30 entries and should be 45.
Lost partition checker initializes out-of-bounds.

Info

o About the hideparttable

For each partition it can be specified which other partitions need to
be hidden when that partition is booted. This is useful for legacy DOS
but also braindead Windows that presents HPFS/JFS partitions as
unformatted and tries to persuade the user to format them.
With v1.07 the numer of partitions that can be handled was expanded from
30 to 45, but the size of the hideparttable was overseen.

o The need to compress the hideparttable

The old size was 30x30=900 bytes while the required size is 45x45=2045 bytes.
This amount of space is not available in the image.
Since 6 bits are enough to identify the partition number to be hidden,
the solution is to devide the table into bitfields. This will result
in a table of (45*45*6)/8=1519 bytes, which can be fitted.

Changes

Revamped the sources quite a bit and moved the history to a separate
file. (AIR-BOOT.HIS)

New

o FIXCODE script for Linux

Just until the C version is ready...

File size: 43.5 KB

Line
1	; AiR-BOOT (c) Copyright 1998-2008 M. Kiewitz
2	;
3	; This file is part of AiR-BOOT
4	;
5	; AiR-BOOT is free software: you can redistribute it and/or modify it under
6	; the terms of the GNU General Public License as published by the Free
7	; Software Foundation, either version 3 of the License, or (at your option)
8	; any later version.
9	;
10	; AiR-BOOT is distributed in the hope that it will be useful, but WITHOUT ANY
11	; WARRANTY: without even the implied warranty of MERCHANTABILITY or FITNESS
12	; FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13	; details.
14	;
15	; You should have received a copy of the GNU General Public License along with
16	; AiR-BOOT. If not, see <http://www.gnu.org/licenses/>.
17	;
18	;---------------------------------------------------------------------------
19	; AiR-BOOT / DRIVE I/O
20	;---------------------------------------------------------------------------
21
22
23
24	IFDEF ModuleNames
25	DB 'DRIVEIO',0
26	ENDIF
27
28	; Note: Some routines set DS/ES to CS or even address via CS, even if its not
29	; needed. This was done for SECURITY. So DO NOT remove it.
30	; Its there to make sure the correct data is loaded/written to/from
31	; harddrive.
32	;
33	; IF YOU MODIFY ANYTHING IN HERE, YOU MAY EASILY BREAK YOUR HARDDRIVE!
34
35	; Will only load base-configuration, will NOT load IPT nor Hide-Config
36	; Those are originally loaded on startup and will NOT get reloaded.
37	DriveIO_LoadConfiguration Proc Near Uses ax bx cx dx es
38	mov ax, cs
39	mov es, ax
40	mov bx, offset Configuration
41	mov dx, 0080h ; First harddrive, Sector 55...
42	mov cx, 0037h
43	mov ax, 0201h ; Function 02, read 1 sector...
44	int 13h
45	jnc DIOLC_NoError
46	call MBR_LoadError ; Will Abort BootUp
47	DIOLC_NoError:
48	ret
49	DriveIO_LoadConfiguration EndP
50
51	DriveIO_SaveConfiguration Proc Near Uses ax bx cx dx ds es si
52	mov ax, cs
53	mov ds, ax
54	mov es, ax ; Safety first (CS==DS==ES)
55	; --- Overwrite Floppy-Name with "FloppyDrive"
56	mov si, offset TXT_Floppy_Drive
57	mov di, offset PartitionTable
58	sub di, 30 ; Adjust to Floppy-Name
59	mov cx, 11
60	rep movsb
61	mov si, offset Configuration ; Calculate new checksum
62	xor bx, bx
63
64	; Changed from 5 to calculated value (not here, see compat. issue below)
65	; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
66	; Size of the ab-configuration in 512 byte sectors
67	;mov cx, (MBR_BackUpMBR - Configuration) / 200h
68
69	; AB v1.07 stores a 5 sector configuration with a 5 sector checksum.
70	; AB v1.0.8 should stores a 7 sector configuration with a
71	; 7 sector checksum.
72	; Because 5 was hardcoded here, SET(A)BOOT v1.07 will see see an AB v1.0.8
73	; config as corrupted, while this is not the case.
74	; So, for compatibility reasons, in v1.0.8, the checksum stored is over
75	; 5 sectors, to be compatible with v1.07.
76	; This may change (be corrected) in future versions !
77	mov cx,5
78
79	mov dx, [CFG_CheckConfig]
80	mov [CFG_CheckConfig], bx
81	DIOSC_Loop:
82	call MBR_GetCheckOfSector
83	loop DIOSC_Loop
84	mov [CFG_CheckConfig], bx
85	; --------------------------------------------------------------------
86	; ES == CS
87	mov bx, offset Configuration
88	mov dx, 0080h ; First harddrive, Sector 55...
89	mov cx, 0037h
90
91	; Changed from 5 to calculated value
92	; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
93	; Size of the ab-configuration in 512 byte sectors
94	mov al, (MBR_BackUpMBR - Configuration) / 200h
95	mov ah,03h
96
97	int 13h
98	jnc DIOSC_NoError
99	call MBR_SaveError ; Will Abort BootUp
100	DIOSC_NoError:
101	ret
102	DriveIO_SaveConfiguration EndP
103
104	DriveIO_UpdateFloppyName Proc Near Uses bx cx dx ds si es di
105	mov ax, cs
106	mov ds, ax
107	mov es, ax
108
109	mov ah, 00h ; Function 2 - Reset Drive
110	xor dl, dl
111	int 13h
112	xor dx, dx ; Cylinder=0, Head=0
113	mov cx, 1 ; Sector=1, Drive=0
114	mov bx, offset TmpSector ; ES:BX - TmpSector
115	mov ax, 0201h ; Function 2 - Load Sector
116	int 13h
117	jnc DIOUFN_AllFine
118
119	; --- Overwrite Floppy-Name with "No Disc"
120	mov si, offset TXT_Floppy_NoDisc
121	xor ax, ax
122	DIOUFN_WriteFloppyName:
123	mov di, offset PartitionTable
124	sub di, 30 ; Adjust to Floppy-Name
125	mov cl, 11
126	rep movsb
127	ret ; AX=-1 -> GotDisc, =0 -> NoDisc
128
129	; --- Floppy found and read, data in TempSector
130	DIOUFN_AllFine:
131	mov ax, -1
132	mov si, offset TXT_Floppy_NoName
133	cmp wptr es:[bx+54], 'AF'
134	jne DIOUFN_WriteFloppyName
135	cmp wptr es:[bx+56], '1T'
136	jne DIOUFN_WriteFloppyName
137	cmp bptr es:[bx+58], '2'
138	jne DIOUFN_WriteFloppyName
139	mov si, bx
140	add si, 43 ; FAT12 - Volume Label Location
141	jmp DIOUFN_WriteFloppyName
142	DriveIO_UpdateFloppyName EndP
143
144	; =============================================================================
145	; HARDDRIVE / GENERAL ACCESS
146	; =============================================================================
147	; The following routines are used for harddisc/floppy access.
148	; The access is done via INT 13h/CHS or INT 13h/LBA.
149	; Access will be done prefered by INT 13h/CHS, because it's (I wonder!) much
150	; faster, than the LBA-method. I don't know, why LBA is so slow. Perhaps BIOS.
151	;
152	; Internal access (to AiR-BOOT) is always done via INT 13h/CHS.
153
154	DriveIO_GetHardDriveCount Proc Near Uses ds si
155	push ds
156	push si
157	push 0040h
158	pop ds
159	mov si, 0075h
160	mov dh, ds:[si] ; 40:75 -> POST: Total Harddiscs == DL
161	pop si
162	pop ds
163	mov TotalHarddiscs, dh
164	ret
165	DriveIO_GetHardDriveCount EndP
166
167
168	; Fills our LBA-Usage table. It holds the LBA-address, where BIOS/CHS access is
169	; stopped and BIOS/LBA access is started.
170	; This is calculated by Sector*Heads. Comparing will get done with Bit 25-10
171	; on LBA sectors, so we actually divide sector number by 1024.
172	DriveIO_InitLBASwitchTable Proc Near Uses es di
173	mov di, offset LBASwitchTable
174	mov dh, TotalHarddiscs
175	mov dl, 80h
176	DIOILUT_DriveLoop:
177	push dx
178	push di
179	mov ah, 08h
180	int 13h ; DISK - GET DRIVE PARAMETERS
181	mov ah, 0FBh ; Assume 255 heads/63 sectors, if error
182	jc DIOILUT_Error
183	and cl, 111111b ; Isolate lower 6 bits of CL -> sector count
184
185	;movzx ax, cl
186	mov al,cl
187	mov ah,0
188
189	mov bl, dh ; DH -> max head number
190	mul bl ; AX = Sectors*Heads
191	shl ah, 1
192	shl ah, 1 ; Shift 2 bits, so we are able to compare to
193	; bit 16-23 of the LBA address
194	DIOILUT_Error:
195	pop di
196	pop dx
197	mov bptr ds:[di], ah ; Save that value
198	inc di ; Go to next BYTE
199	inc dl
200	dec dh
201	jnz DIOILUT_DriveLoop
202	ret
203	DriveIO_InitLBASwitchTable EndP
204
205
206
207
208	; Adjusts BX:AX / CX:DX to meet LVM sector location
209	; Destroys SI
210	; Rousseau: Enhanced to handle sector-numbers 127 and 255 besides 63 for LVM-info sectors.
211	; Ugly, need to cleanup.
212	DriveIO_LVMAdjustToInfoSector Proc Near
213
214	;~ pusha
215	;~ call AuxIO_TeletypeNL
216	;~
217	;~ ; LBA
218	;~ xchg dx,bx
219	;~ call AuxIO_TeletypeHexDWord
220	;~ call AuxIO_TeletypeNL
221	;~ xchg bx,dx
222	;~
223	;~ ; CYL
224	;~ mov al,ch
225	;~ call AuxIO_TeletypeHexByte
226	;~ call AuxIO_TeletypeNL
227	;~
228	;~ ; HEAD
229	;~ mov al,dh
230	;~ call AuxIO_TeletypeHexByte
231	;~ call AuxIO_TeletypeNL
232	;~
233	;~ ; SEC
234	;~ mov al,cl
235	;~ call AuxIO_TeletypeHexByte
236	;~ call AuxIO_TeletypeNL
237	;~
238	;~ ; DRIVE
239	;~ mov al,dl
240	;~ call AuxIO_TeletypeHexByte
241	;~ call AuxIO_TeletypeNL
242	;~ popa
243	;~
244	;~ ;local ts:word
245	;~ ;local ts2:word
246
247	pusha
248
249	; Dump drive
250	mov si,offset drive
251	;call AuxIO_Print
252	xchg al,dl
253	;call AuxIO_TeletypeHexByte
254	;call AuxIO_TeletypeNL
255	xchg dl,al
256
257	; Dump SPT
258	mov si,offset spt_used
259	;call AuxIO_Print
260	push dx
261	push bx
262	xor dh,dh
263	and dl,01111111b
264	shl dx,1
265	shl dx,1
266	mov bx, offset TrueSecs
267	add bx,dx
268	mov ax,word ptr [bx]
269	;mov [ts],ax
270	;call AuxIO_TeletypeHexWord
271	;call AuxIO_TeletypeNL
272	pop bx
273	pop dx
274
275	pusha
276	push dx
277	; Location of extended position
278	mov dx,word ptr [ExtendedAbsPos+02]
279	mov ax,word ptr [ExtendedAbsPos+00]
280	;call AuxIO_TeletypeHexDWord
281	;call AuxIO_TeletypeNL
282	pop dx
283
284	xor dh,dh
285	and dl,01111111b
286	shl dx,1
287	shl dx,1
288	mov bx, offset TrueSecs
289	add bx,dx
290
291	mov ax, word ptr[bx]
292	;call AuxIO_TeletypeHexWord
293	;call AuxIO_TeletypeNL
294	mov al,[ExtendedAbsPosSet] ; if true -> 1st sector of extpart (EBR), not logpart(BPB)
295	;call AuxIO_TeletypeHexByte
296	;call AuxIO_TeletypeNL
297	;mov si,offset PartitionSector
298	;call AuxIO_DumpSector
299	popa
300
301	; LBA
302	mov si,offset before_lvm_adjust
303	;call AuxIO_Print
304
305	xchg dx,bx
306	;call AuxIO_TeletypeHexDWord
307	;call AuxIO_TeletypeNL
308	xchg bx,dx
309	popa
310
311
312	;or bx,ax
313	test [ExtendedAbsPosSet],1
314	jz pri
315
316
317
318
319	pusha
320	mov si,offset before_lvm_adjust_log
321	;call AuxIO_Print
322	; LBA
323	xchg dx,bx
324	;call AuxIO_TeletypeHexDWord
325	;call AuxIO_TeletypeNL
326	xchg bx,dx
327	popa
328
329
330	push dx
331	push bx
332
333	xor dh,dh
334	and dl,01111111b
335	shl dx,1
336	shl dx,1
337	mov bx,offset TrueSecs
338	add bx,dx
339	mov dx,[bx]
340	dec dx
341	add ax,dx
342
343	pop bx
344	pop dx
345	adc bx,0
346
347
348	pusha
349	mov si,offset after_lvm_adjust_log
350	;call AuxIO_Print
351	; LBA
352	xchg dx,bx
353	;call AuxIO_TeletypeHexDWord
354	;call AuxIO_TeletypeNL
355	xchg bx,dx
356	popa
357
358	jmp done
359
360
361
362
363	pri:
364
365
366	push ax
367	push cx
368	xor ch, ch ; Zero out upper-byte
369
370	push dx
371	xor dh,dh
372	and dl,01111111b
373	shl dx,1
374	shl dx,1
375
376	push bx
377	mov bx,offset TrueSecs
378	add bx,dx
379	mov ax,[bx]
380	;mov [ts2],ax
381	pop bx
382	pop dx
383
384
385
386	;~ mov al, 63
387	;~ call VideoIO_PrintByteDynamicNumber
388	;~ self: jmp self
389
390
391
392	; DEZE WERKT SOMS NIET GOED
393	; ROMMELT MET CYLINDERS
394	; ALLEEN TOEPASSEN ALS INT13X NIET ACTIEF !
395
396	and cl, al ; Isolate lower bits, because upper
397	mov ah, 0
398	mov si, ax ; ones may be used for cylinder
399	sub si, cx
400
401	pop cx
402	pop ax
403
404	or cl, al ; Set sector to last sector
405	add ax, si ; Adjust lower LBA
406	adc bx, 0 ; Adjust LBA Sector (BX:AX)
407
408
409
410	;~ push ax
411	;~ call AuxIO_TeletypeHexWord
412	;~ call AuxIO_TeletypeNL
413	;~ mov ax,[ts]
414	;~ call AuxIO_TeletypeHexWord
415	;~ call AuxIO_TeletypeNL
416	;~ mov ax,[ts2]
417	;~ call AuxIO_TeletypeHexWord
418	;~ call AuxIO_TeletypeNL
419	;~ pop ax
420
421	;~ and ax,[ts]
422
423	jmp done
424
425
426
427	done:
428
429	pusha
430	mov si,offset after_lvm_adjust
431	;~ call AuxIO_Print
432	; LBA
433	xchg dx,bx
434	;~ call AuxIO_TeletypeHexDWord
435	;~ call AuxIO_TeletypeNL
436	xchg bx,dx
437	popa
438
439	;~ pusha
440	;~ call AuxIO_TeletypeNL
441	;~
442	;~ ; CYL
443	;~ mov al,ch
444	;~ call AuxIO_TeletypeHexByte
445	;~ call AuxIO_TeletypeNL
446	;~
447	;~ ; HEAD
448	;~ mov al,dh
449	;~ call AuxIO_TeletypeHexByte
450	;~ call AuxIO_TeletypeNL
451	;~
452	;~ ; SEC
453	;~ mov al,cl
454	;~ call AuxIO_TeletypeHexByte
455	;~ call AuxIO_TeletypeNL
456	;~
457	;~ ; DRIVE
458	;~ mov al,dl
459	;~ call AuxIO_TeletypeHexByte
460	;~ call AuxIO_TeletypeNL
461	;~ popa
462
463	ret
464	DriveIO_LVMAdjustToInfoSector EndP
465
466
467
468	drive db 'drive : ',0
469	before_lvm_adjust db 'before lvm adjust : ',0
470	after_lvm_adjust db 'after lvm adjust : ',0
471	before_lvm_adjust_log db 'before lvm logical adjust: ',0
472	after_lvm_adjust_log db 'after lvm logical adjust : ',0
473	spt_used db 'spt used : ',0
474
475
476
477	; #########################################################################
478	; Routine: Loads partition to ExecBase and checks for validity
479	; #########################################################################
480	; Calling : bx:ax - Absolute sector
481	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
482	; Returns : Carry Set if invalid partition encountered
483	; Preserve: all registers
484	; #########################################################################
485	DriveIO_LoadPartition Proc Near Uses si
486	mov wptr cs:[CurPartition_Location+0], ax
487	mov wptr cs:[CurPartition_Location+2], bx
488	mov wptr cs:[CurPartition_Location+4], dx
489	mov wptr cs:[CurPartition_Location+6], cx ; Saves the location
490	mov si, offset PartitionSector ; DS:SI - ExecBase
491	call DriveIO_LoadSector
492	clc
493	cmp wptr [si+LocBR_Magic], 0AA55h
494	je DIOLP_Success
495	; We check, if we are scanning partitions. In that case, if CHS is not 0/0/1
496	; we will display a "bad partition table" message and halt the system.
497	cmp cx, 0001h
498	jne DIOLP_Failed
499	or dh, dh
500	jnz DIOLP_Failed
501	stc ; Set carry, so no partition table
502	DIOLP_Success:
503
504	IFDEF AUX_DEBUG
505	; show current partition location
506	;~ pushf
507	;~ pusha
508	;~ call AuxIO_TeletypeNL
509	;~ mov si,offset db_curpartloc
510	;~ call AuxIO_Print
511	;~ mov dx,word ptr [CurPartition_Location+02]
512	;~ mov ax,word ptr [CurPartition_Location+00]
513	;~ call AuxIO_TeletypeHexDWord
514	;~ call AuxIO_TeletypeNL
515	;~ mov si,offset PartitionSector
516	;~ call AuxIO_DumpSector
517	;~ call AuxIO_TeletypeNL
518	;~ popa
519	;~ popf
520	ENDIF
521
522	ret
523	DIOLP_Failed:
524	jmp DriveIO_GotLoadError
525	DriveIO_LoadPartition EndP
526
527	; #########################################################################
528	; Routine: Writes a partition from ExecBase to its original sector
529	; #########################################################################
530	; Calling : none
531	; Returns : none
532	; Preserve: all registers
533	; #########################################################################
534	DriveIO_SavePartition Proc Near Uses ax bx cx dx si
535	mov ax, wptr cs:[CurPartition_Location+0]
536	mov bx, wptr cs:[CurPartition_Location+2]
537	mov dx, wptr cs:[CurPartition_Location+4]
538	mov cx, wptr cs:[CurPartition_Location+6] ; Gets prev. saved location
539	mov si, offset PartitionSector ; DS:SI - ExecBase
540	cmp wptr [si+LocBR_Magic], 0AA55h ; Checks for signature, if not found
541	jne DIOSP_SevereError ; we assume a really bad error
542	call DriveIO_SaveSector
543	DIOSP_SevereError:
544	ret
545	DriveIO_SavePartition EndP
546
547	; Keeps DS:SI for caller
548	DriveIO_LoadTmpSector Proc Near
549	mov si, offset TmpSector
550	call DriveIO_LoadSector
551	ret
552	DriveIO_LoadTmpSector EndP
553
554	; Keeps DS:SI for caller
555	DriveIO_SaveTmpSector Proc Near
556	mov si, offset TmpSector
557	call DriveIO_SaveSector
558	ret
559	DriveIO_SaveTmpSector EndP
560
561	; Keeps DS:SI for caller, sets carry if valid LVM sector encountered
562	DriveIO_LoadLVMSector Proc Near Uses ax bx cx dx
563	test [CFG_IgnoreLVM], 1 ; We are supposed to ignore LVM, so
564	jnz DIOLLVMS_NoLVMSector ; don't load but declare as bad!
565	mov ax, wptr cs:[CurPartition_Location+0]
566	mov bx, wptr cs:[CurPartition_Location+2]
567	mov dx, wptr cs:[CurPartition_Location+4]
568	mov cx, wptr cs:[CurPartition_Location+6] ; Gets cur. partition location
569
570	call DriveIO_LVMAdjustToInfoSector
571
572	mov si, offset LVMSector
573	call DriveIO_LoadSector
574
575	IFDEF AUX_DEBUG
576	; show current partition location
577	pushf
578	pusha
579	;~ call AuxIO_TeletypeNL
580	;~ mov si,offset db_curlvmsec
581	;~ call AuxIO_Print
582	mov dx,bx
583	;~ call AuxIO_TeletypeHexDWord
584	;~ call AuxIO_TeletypeNL
585	mov si,offset LVMSector
586	;~ call AuxIO_DumpSector
587	;~ call AuxIO_TeletypeNL
588	popa
589	popf
590	ENDIF
591
592	call LVM_CheckSectorSignature
593	jnc DIOLLVMS_NoLVMSector
594	call LVM_CheckSectorCRC
595	jnc DIOLLVMS_NoLVMSector
596	ret
597	; This here is called, if an invalid (or no) LVM information sector is found
598	; It will truncate the first byte of the sector, so all other routines
599	; will notice it easily by just comparing the first byte.
600	DIOLLVMS_NoLVMSector:
601	mov bptr [si+LocLVM_SignatureStart], 0
602	ret
603	DriveIO_LoadLVMSector EndP
604
605	; Keeps DS:SI for caller, saves at anytime w/o checks (!)
606	DriveIO_SaveLVMSector Proc Near Uses ax bx cx dx
607	test [CFG_IgnoreLVM], 1 ; We are supposed to ignore LVM, so
608	jnz DIOSLVMS_SevereError ; don't save at anytime (security!)
609	mov ax, wptr cs:[CurPartition_Location+0]
610	mov bx, wptr cs:[CurPartition_Location+2]
611	mov dx, wptr cs:[CurPartition_Location+4]
612	mov cx, wptr cs:[CurPartition_Location+6] ; Gets cur. partition location
613	call LVM_CheckSectorSignature
614	jnc DIOSLVMS_SevereError ; LVM Signature must be there
615	call DriveIO_LVMAdjustToInfoSector
616	mov si, offset LVMSector
617	call DriveIO_SaveSector
618	DIOSLVMS_SevereError:
619	ret
620	DriveIO_SaveLVMSector EndP
621
622	; Rousseau: Move this to BSS and merge with int13xbuf there.
623
624	; Memory-Block that holds information for LBA-access via INT 13h
625	DriveIO_DAP db 10h ; Size of paket
626	db 0 ; Reserved
627	DriveIO_DAP_NumBlocks dw 0 ; Number of blocks
628	DriveIO_DAP_Transfer dd 0 ; Transfer Adress
629	DriveIO_DAP_Absolute dd 0 ; Absolute Sector
630	dd 0 ; Second Part of QWORD
631
632	; Special error message instead of "LOAD ERROR" during partition scanning,
633	; so users will notice that something is bad with their partition table(s)
634	DriveIO_GotLoadError Proc Near
635	test cs:CurIO_Scanning, 1 ; Must be CS:, cause DS!=CS maybe here
636	jnz InScanMode
637	jmp MBR_LoadError
638	InScanMode:
639	mov si, offset TXT_BrokenPartitionTable
640	push cs
641	pop ds
642	call MBR_Teletype
643	mov si, offset BrokenHDD
644	sub dl, 50h ; 80h -> '0'
645	cmp dl, 39h
646	jbe DIOGLE_BelowA
647	add dl, 7 ; 3Ah -> 'A'
648	DIOGLE_BelowA:
649	mov bptr [si+5], dl
650	call MBR_Teletype
651
652	; JWasm: cannot jump to local label in other procedure.
653	; Changed to halt here.
654	;jmp MBRLE_Halt
655	DriveIO_GotLoadError_halt:
656	jmp DriveIO_GotLoadError_halt
657	DriveIO_GotLoadError EndP
658
659	; #########################################################################
660	; Routine: Loads a specified sector to DS:DI
661	; #########################################################################
662	; Calling : bx:ax - Absolute sector
663	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
664	; ds:si - Destination-Adress
665	; Returns : none
666	; Preserve: all registers
667	; #########################################################################
668	DriveIO_LoadSector Proc Near Uses ax bx ds si es di
669	; Is the drive not a harddrive?
670	cmp dl, 80h
671	jb DIOLS_UseNormal
672
673	test cs:[CurIO_UseExtension], 1
674	jz DIOLS_UseNormal
675	; Are we forced do use LBA via Setting?
676	jnz DIOLS_UseExtension
677
678	; Upper 8 bits of LBA-address set? -> Use LBA (maximum boundary is FB0400h)
679	or bh, bh
680	jnz DIOLS_UseExtension
681	; Compare Switch-Table value to bit 16-23 of LBA-address
682	mov di, dx
683	and di, 007Fh
684	cmp bptr cs:[LBASwitchTable+di], bl
685	jbe DIOLS_UseExtension
686	DIOLS_UseNormal:
687	mov di, 3
688	DIOLS_ErrorLoop:
689	push ds
690	pop es
691	mov bx, si ; ES:BX - Destination
692	mov ax, 0201h ; Function 2 - Load Sector
693	int 13h
694	jnc DIOLS_Success
695	dec di
696	jnz DIOLS_ErrorLoop
697	; Sector load failed...
698	jmp DriveIO_GotLoadError
699
700	DIOLS_UseExtension:
701	push cx
702	mov cs:[DriveIO_DAP_NumBlocks], 1 ; Copy ONE sector
703	mov wptr cs:[DriveIO_DAP_Transfer+0], si
704	mov cx, ds
705	mov wptr cs:[DriveIO_DAP_Transfer+2], cx ; Fill out Transfer Adress
706	mov wptr cs:[DriveIO_DAP_Absolute+0], ax
707	mov wptr cs:[DriveIO_DAP_Absolute+2], bx ; Fill out Absolute Sector
708	push cs
709	pop ds
710	mov si, offset DriveIO_DAP
711	mov ah, 42h ; Extended Read
712	int 13h
713	pop cx
714	jnc DIOLS_Success
715	; Sector load failed...
716	jmp DriveIO_GotLoadError
717
718	DIOLS_Success:
719	ret
720	DriveIO_LoadSector EndP
721
722
723
724	;
725	; ############################################################
726	; # Load a specified sector from a disk using LBA addressing #
727	; ############################################################
728	;
729	; In
730	; --
731	; DL = Physical Disk
732	; BX:CX = LBA sector
733	; DI:SI = Target buffer
734	;
735	; Out
736	; ---
737	; AX = Error code
738	;
739	DriveIO_LoadSectorLBA Proc Near Uses bx cx dx si di ds es
740	; Get one sector
741	mov cs:[DriveIO_DAP_NumBlocks], 1
742
743	; Setup buffer address
744	mov wptr cs:[DriveIO_DAP_Transfer+0], si
745	mov wptr cs:[DriveIO_DAP_Transfer+2], di
746
747	; Setup LBA address of requested sector
748	mov wptr cs:[DriveIO_DAP_Absolute+0], cx
749	mov wptr cs:[DriveIO_DAP_Absolute+2], bx
750	mov wptr cs:[DriveIO_DAP_Absolute+4], 0
751	mov wptr cs:[DriveIO_DAP_Absolute+6], 0
752
753	; Address of packet
754	mov si, offset DriveIO_DAP
755
756	; Do the extended read
757	mov ah, 42h
758	int 13h
759
760	; Looking good so far
761	jnc DriveIO_LoadSectorLBA_succes1
762
763	; AH should not be zero, if it is then set to undefined and set carry
764	test ah,ah
765	jnz DriveIO_LoadSectorLBA_error1
766	mov ah, 0bbh ; Undefined error
767	DriveIO_LoadSectorLBA_error1:
768	stc
769	jmp DriveIO_LoadSectorLBA_exit
770
771	; AL should be zero, if not then set to undefined and set carry
772	DriveIO_LoadSectorLBA_succes1:
773	test ah,ah
774	jz DriveIO_LoadSectorLBA_exit
775	stc
776	jmp DriveIO_LoadSectorLBA_exit
777
778	; Return to caller
779	DriveIO_LoadSectorLBA_exit:
780	ret
781	DriveIO_LoadSectorLBA EndP
782
783
784
785
786	; #########################################################################
787	; Routine: Writes DS:SI to a specified sector
788	; #########################################################################
789	; Calling : bx:ax - Absolute sector
790	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
791	; ds:si - Source-Adress
792	; Returns : none
793	; Preserve: all registers
794	; #########################################################################
795	DriveIO_SaveSector Proc Near Uses ax bx cx ds si es di
796	test cs:[CurIO_UseExtension], 1
797	jz DIOSS_UseNormal
798	; Are we forced do use LBA via Setting?
799	test cs:[CFG_ForceLBAUsage], 1
800	jnz DIOSS_UseExtension
801	; Is the drive not a harddrive?
802	cmp dl, 80h
803	jb DIOSS_UseNormal
804	; Upper 8 bits of LBA-address set? -> Use LBA (maximum boundary is FB0400h)
805	or bh, bh
806	jnz DIOSS_UseExtension
807	; Compare Switch-Table value to bit 16-23 of LBA-address
808	mov di, dx
809	and di, 007Fh
810	cmp bptr cs:[LBASwitchTable+di], bl
811	jbe DIOSS_UseExtension
812	DIOSS_UseNormal:
813	mov di, 3
814	DIOSS_ErrorLoop:
815	push ds
816	pop es
817	mov bx, si ; ES:BX - Destination
818	mov ax, 0301h ; Function 3 - Write Sector
819	int 13h
820	jnc DIOSS_Success
821	dec di
822	jnz DIOSS_ErrorLoop
823	call MBR_SaveError
824
825	DIOSS_UseExtension:
826	push cx
827	mov cs:[DriveIO_DAP_NumBlocks], 1 ; Copy ONE sector
828	mov wptr cs:[DriveIO_DAP_Transfer+0], si
829	mov cx, ds
830	mov wptr cs:[DriveIO_DAP_Transfer+2], cx ; Fill out Transfer Adress
831	mov wptr cs:[DriveIO_DAP_Absolute+0], ax
832	mov wptr cs:[DriveIO_DAP_Absolute+2], bx ; Fill out Absolute Sector
833	push cs
834	pop ds
835	mov si, offset DriveIO_DAP
836	mov ax, 4300h ; Extended Write (No Verify)
837	int 13h
838	pop cx
839	jnc DIOSS_Success
840	call MBR_SaveError
841
842	DIOSS_Success:
843	ret
844	DriveIO_SaveSector EndP
845
846
847	; See if a LVM-sector is valid.
848	; In : si, pointer to sector
849	; Out : CY if valid LVM sector, NC if not
850	DriveIO_LVMSectorValid Proc Near
851	pusha
852
853	call LVM_CheckSectorSignature
854	; NC if no signature found
855	jnc DriveIO_LVMSectorValid_End
856
857	call LVM_CheckSectorCRC
858	; Force valid !!!
859	stc
860
861	DriveIO_LVMSectorValid_End:
862	popa
863	ret
864	DriveIO_LVMSectorValid EndP
865
866	; ------------------------------------------------------
867	; Rousseau: # Load the master LVM-sector if one exists #
868	; ------------------------------------------------------
869	; Load the master LVM-sector to get the number of sectors per track as eCS views the drive.
870	; If no master LVM-sector is found it is assumed eCS is not installed.
871	; The master LVM-sector can be located at three different places according to drive size
872	; and partitioning scheme and driver used.
873	; When DANIS506.ADD is used, the eCS extended geometry will be 255/127 for drives >502GiB but <1TiB.
874	; Then the location will be sector 127 which is LBA 126 (7Eh).
875	; IBM1S506.ADD will always use 255/255 for the extended eCS geometry.
876	; DANIS506.ADD will use 255/255 for drives >1TiB.
877	; Then the location of the master LVM-sector will be 255 which is LBA 254 (FEh).
878	; When eCS is installed on a huge drive that alread had a system on it, eCS will be confined to the
879	; lower 502GiB of the drive. In this case the normal geometry from Int13X will be used.
880	; This is also the case when no valid master LVM-sector can be found.
881	;
882	; Return CF when valid master LVM sector found, NC if not.
883	; Loads sector at [LVMSector] !
884	DriveIO_LoadMasterLVMSector Proc Near
885	pusha
886
887	;~ mov si,offset db_lmlvm
888	;~ call AuxIO_Print
889
890	;~ ; Physical disk
891	;~ mov al,'<'
892	;~ call VideoIO_PrintSingleChar
893	;~ mov al,dl
894	;~ call VideoIO_PrintHexByte
895	;~ mov al,'>'
896	;~ call VideoIO_PrintSingleChar
897	;~
898	;~ call AuxIO_TeletypeHexByte
899	;~ call AuxIO_TeletypeNL
900
901
902	; Loop over the sector-translation table,
903	; process the first three values from high (255) to low (bios spt, most likely 63)
904	mov cx,3
905	DriveIO_LoadMasterLVMSector_NextTry:
906	; Number of sectors to read
907	mov [DriveIO_DAP_NumBlocks],1
908
909	; Setup destination address
910	mov si, offset LVMSector
911	mov wptr [DriveIO_DAP_Transfer+0],si
912	mov ax, ds
913	mov wptr [DriveIO_DAP_Transfer+2],ax
914
915	; Get the sector-number of the next possible LVM sector (255,127,63)
916	; using the translation table and the counter as the index
917	mov bx,offset secs_per_track_table
918	mov ax,cx
919	dec ax
920	xlatb
921	dec al
922
923	;
924	; AX now contains the LBA address of the sector
925	; that could be an LVM sector.
926	; This is all in track0 so the address will not exceed 64kiB sectors.
927	;
928
929	;~ push ax
930	;~ push ax
931	;~ mov al,'$'
932	;~ call VideoIO_PrintSingleChar
933	;~ pop ax
934	;~ call VideoIO_PrintHexByte
935	;~ mov al,'$'
936	;~ call VideoIO_PrintSingleChar
937	;~ pop ax
938
939	IFDEF AUX_DEBUG
940	; Dump the value
941	;call AuxIO_TeletypeHexByte
942	;call AuxIO_TeletypeNL
943	ENDIF
944
945	; Setup the requested LBA sector number
946	mov wptr [DriveIO_DAP_Absolute+0],ax ; LBA low
947	mov wptr [DriveIO_DAP_Absolute+2],00h ; LBA high
948	mov si, offset DriveIO_DAP ; address request packet
949	mov ah, 42h
950	int 13h ; do the i/o
951	cmc ; Complement carry so we can exit imm. on error
952	jnc DriveIO_LoadMasterLVMSector_End ; oops, return with NC
953
954
955	mov si,offset LVMSector
956
957	; See if this is a valid LVM-sector
958	call DriveIO_LVMSectorValid
959
960	; pushf
961	; mov ah,0
962	; rcl ah,1
963	; mov al,'\|'
964	; call VideoIO_PrintSingleChar
965	; mov al,ah
966	; call VideoIO_PrintHexByte
967	; mov al,'\|'
968	; call VideoIO_PrintSingleChar
969	; popf
970
971
972	; Yep, we found the master LVM-sector
973	jc DriveIO_LoadMasterLVMSector_Found
974	; Try next location
975	loop DriveIO_LoadMasterLVMSector_NextTry
976
977	; No master LVM-sector found, set CF=false
978	clc
979
980	DriveIO_LoadMasterLVMSector_Found:
981	DriveIO_LoadMasterLVMSector_End:
982	popa
983	ret
984	DriveIO_LoadMasterLVMSector Endp
985
986
987
988
989	; ---------------------------------------------------
990	; Rousseau ## Large drives, (eCS) geometry and LBA ##
991	; ---------------------------------------------------
992	; A sector size of 512 bytes is assumed in the below calculations.
993	; Note that this scheme changes when the sector size will be 4096 or larger,
994	; like with modern drives that do not translate to 512 bytes per sector anymore.
995	; These drives will have a capacity above the 2TiB LBA32 boundary.
996	; For now, we assume drives <=2TiB with a sector size of 512 bytes.
997
998	; There are a few boundaries that are of importance.
999	; Note that these are disk-boundaries and not partition boundaries.
1000	; Even with a small partition, like <502GiB, OS/2 will use extended geometry on an
1001	; empty huge disk.
1002	; These boundaries are (from high to low):
1003
1004	; (code 5)
1005	; 2^32 = 4294967296 = 100000000 sectors = 2048 GiB
1006	; This is the LBA32 2TiB boundary.
1007	; Everything above it must be addressed using LBA48.
1008	; OS/2 can currently not address this space above.
1009
1010	; (code4)
1011	; 65536255255 = 4261478400 = FE010000 sectors ~ 2032 GiB
1012	; This is the max OS/2 boundary using 255/255 extended geometry.
1013	; OS/2 can currently not address this space above.
1014
1015	; (code 3)
1016	; 2^31 = 2147483648 = 80000000 sectors = 1024 GiB
1017	; This is the LBA32 1TiB boundary.
1018	; OS/2 can address this space and will use 255/255 extended geometry.
1019
1020	; (code 2)
1021	; 65536255127 = 2122383360 = 7E810000 sectors ~ 1012 GiB
1022	; This is the DANI 1TiB boundary.
1023	; OS/2 can address this space and will use 255/255 extended geometry.
1024	; Below this DANI will use 255/127 extended geometry.
1025	; This matters on where the LVM-sectors are located !
1026
1027	; (code 1)
1028	; 6553625563 = 1052835840 = 3EC10000 sectors ~ 502 GiB
1029	; This is the current OS/2 limit using this geometry because OS/2 can currently
1030	; not address more than 65536 cylinders.
1031	; DANI will address space above with 255/127 extended geometry up until the DANI 1TiB boundary (code 2)
1032
1033	; (code 0)
1034	; Everything below 6553625563 will be addressed using standard geometry.
1035
1036
1037	;
1038	; This function will return the following values:
1039	;
1040
1041	; 5 = This drive is above the 2^32 LBA32 (2TB) boundary and has more than 4294967296 sectors.
1042	; LBA48 addressing is needed to access the complete capacity of the drive.
1043	; OS/2 is currently unable to do so.
1044
1045	; 4 = This drive is above the 65536255255 (4261478400) boundary but below 2^32.
1046	; This is an OS/2 boundary and OS/2 is not able to access the drive above this boundary.
1047
1048	; 3 = This drive is above the 2^31 (1TB) boundary and has more than 2147483648 sectors.
1049	; OS/2 is able to access the drive using it's extended geometry.
1050	; Both DANIS506 and IBM1S506 will use the 255/255 scheme.
1051
1052	; 2 = This drive is above the 65536255127 (2122383360) boundary but below 2^31.
1053	; OS/2 is able to access the drive using it's extended geometry.
1054	; Both DANIS506 and IBM1S506 will use the 255/255 scheme.
1055
1056	; 1 = This drive is above the 6553625563 (1052835840) boundary but below 65536255127.
1057	; OS/2 is able to access the drive using it's extended geometry.
1058	; Note that DANIS506 will use 255/127 and IBM1S506 will use 255/255 geometry !
1059	; Using DANI or IBM influences the location of the LVM info-sectors !
1060
1061	; 0 = This drive is below the 6553625563 (1052835840) boundary.
1062	; OS/2 is able to access this drive using the standard 255/63 geometry.
1063
1064	; So, any return value >0 means OS/2 extended geometry will be used.
1065	; Value 1 will use 255/127 with DANIS506 but 255/255 with IBM1S506.
1066	; Values 2 and 3 will use 255/255 on both drivers.
1067	; You can or with 0x01 and check for 3 in this case.
1068	; Any value above 3 will be a drive who's capacity cannot be fully used by OS/2
1069	; The upper limit of 65536255255 will be in effect here.
1070
1071	; Note this function currently handles the boot-drive only !
1072	; It should be extended and use dl for the drive-number as a parameter.
1073	; Because we use this function to get this info in a number of places,
1074	; all regs and flags except AX are saved and restored.
1075
1076	; DL contains BIOS disk-number; 80h for first, 81h for second, etc.
1077	DriveIO_GatherDiskInfo Proc Near
1078	pushf
1079	push bx
1080	push cx
1081	push dx
1082	push si
1083	push di
1084	push es
1085
1086	; Set ES to CS for buffer clearing
1087	push cs
1088	pop es
1089
1090	; Clear the buffer
1091	; Also setup the buffer size.
1092	; Old Phoenix BIOSses require word (flags) at 02 to be zero,
1093	; so we clear the whole buffer to be sure.
1094	mov cx, i13xbuf_size ; Dynamically calculated by assembler.
1095	mov di, offset i13xbuf ; Points to size field.
1096	mov [di],cx ; Setup buffer-size.
1097	inc di
1098	inc di ; Now pointing at actual buffer.
1099	xor ah,ah ; Fill value.
1100	cld ; Direction up.
1101	rep stosb ; Clear buffer.
1102
1103	; Get the drive parameters
1104	mov ah, 48h ; Get Drive Parameters (extended version)
1105	;mov dl, 80h ; Drive number
1106	mov si, offset i13xbuf ; Buffer for result-info
1107	push dx
1108	int 13h ; Call the BIOS-function
1109	pop dx
1110
1111	; Do some error-checking
1112	or ah,ah ; AH is zero if no error (ZF=1 if no error)
1113	mov ax,0 ; Setup code for non-huge drive (does not influence ZF)
1114	jz DriveIO_GatherDiskInfo_ok ; Return if error (AL<>0 thus ZF=0) but CY not set, assuming non-huge drive
1115	jnc DriveIO_GatherDiskInfo_ok ; Return if error (CY=1), assuming non-huge drive
1116	jmp DriveIO_GatherDiskInfo_ret
1117
1118
1119	DriveIO_GatherDiskInfo_ok:
1120
1121	;
1122	; Store the drive geometry
1123	;
1124
1125	mov si, offset i13xbuf
1126
1127	xor dh,dh
1128	and dl,01111111b
1129	shl dx,1
1130	shl dx,1
1131
1132	; Store number of cylinders on disk
1133	mov bx, offset BIOS_Cyls
1134	add bx,dx
1135	mov ax,[si+04h]
1136
1137	mov word ptr [bx+00],ax
1138	mov ax,[si+06]
1139	mov word ptr [bx+02],ax
1140
1141	; Store number of heads per cylinder
1142	mov bx, offset BIOS_Heads
1143	add bx,dx
1144	mov ax,[si+08h]
1145	mov word ptr [bx+00],ax
1146	mov ax,[si+0ah]
1147	mov word ptr [bx+02],ax
1148
1149	; Store number of sectors per track
1150	mov bx, offset BIOS_Secs
1151	add bx,dx
1152	mov ax,[si+0ch]
1153	mov word ptr [bx+00],ax
1154
1155	; Update first byte of translation-table to conform to BIOS SPT
1156	mov byte ptr [secs_per_track_table], al
1157
1158	mov ax,[si+0eh]
1159	mov word ptr [bx+02],ax
1160
1161	; Store total secs
1162	mov bx, offset BIOS_TotalSecs
1163	add bx,dx
1164	add bx,dx
1165	mov ax,[si+10h]
1166
1167	mov word ptr [bx+00],ax
1168	mov ax,[si+12h]
1169	mov word ptr [bx+02],ax
1170	mov ax,[si+14h]
1171	mov word ptr [bx+04],ax
1172	mov ax,[si+18h]
1173	mov word ptr [bx+06],ax
1174
1175	; Store number of bytes per sector
1176	mov bx, offset BIOS_Bytes
1177	add bx,dx
1178	mov ax,[si+18h]
1179	mov [bx],ax
1180
1181
1182	;
1183	; See of it's a huge drive of not
1184	;
1185
1186	; Drive is larger than 2TiB
1187	mov ax,5 ; Drive code (5)
1188	mov bx, [si+14h] ; Low word of high dword of sector-count
1189	or bx, [si+16h] ; High word of high dword of sector-count
1190	jnz DriveIO_GatherDiskInfo_ret ; If non-zero we have a drive with >2^32 sectors and thus LBA48 addressing
1191
1192	; Drive is larger than max OS/2 capacity
1193	dec ax ; Drive code (4)
1194	mov bx, [si+12h] ; High word of low dword of sector-count
1195	cmp bx, 0fe01h ; Boundary
1196	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1197	; we have a drive larger than to 65536255255 = FE010000 sectors
1198
1199	; Drive can be completely utilized by OS/2
1200	dec ax ; Drive code (3)
1201	cmp bx, 8000h ; Boundary
1202	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1203	; we have a drive larger than 2^31 sectors but smaller than 65536255255
1204
1205	; This is the small area between DANI 1TiB and LBA 1TiB
1206	dec ax ; Drive code (2)
1207	cmp bx, 7e81h ; Boundary
1208	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1209	; we have a drive larger than 65536255127 but <65536255255
1210	; DANIS506.ADD will use 255/255 extended geometry
1211
1212	; DANI will use 255/127 in this area, this could impact the location of LVM-sectors ! (last sec on track)
1213	dec ax ; Drive code (1)
1214	cmp bx, 3ec1h ; Boundary
1215	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1216	; we have a drive larger than 6553625563 sectors (OS/2 502GiB Limit!)
1217	; DANIS506.ADD will use 255/127 extended geometry !
1218	; IBM1S506.ADD will use 255/255 extended geometry !
1219
1220	; We have a drive that can be addressed using standard 255/63 geometry
1221	dec ax ; Drive code (0)
1222	; We have a drive smaller than 6553625563 = 3EC10000 sectors
1223
1224	DriveIO_GatherDiskInfo_ret:
1225	pop es
1226	pop di
1227	pop si
1228	pop dx
1229	pop cx
1230	pop bx
1231
1232	mov [CurIO_UseExtension],1
1233
1234	popf
1235	ret
1236	DriveIO_GatherDiskInfo EndP
1237
1238
1239
1240	; Values for sectors per track table corresponding to DriveIO_IsHugeDrive return value.
1241	secs_per_track_table db 63,127,255,255,255,255
1242
1243	;db_lmlvm: db 'Load Master LVM -- disk: ',0

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