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source: trunk/bootcode/regular/driveio.asm@ 170

Last change on this file since 170 was 170, checked in by Ben Rietbroek, 8 years ago

Updated debugging state [v1.1.1-testing]

CAUTION:
This is a testbuild !
AirBoot uses the BIOS to access disks and a small coding error can trash
partition tables or other vital disk structures. You are advised to make
backups of TRACK0 and EBRs before using this testbuild. More info at:
https://rousseaux.github.io/netlabs.air-boot/pdf/AirBoot-v1.1.0-manual.pdf

File size: 74.6 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 MODULE_NAMES
25	DB 'DRIVEIO',0
26	ENDIF
27
28	;
29	; Check if INT13X extensions are supported.
30	; AirBoot requires these extensions, and will halt if they are not available.
31	; Modified: [CurIO_UseExtension]
32	DriveIO_CheckFor13extensions Proc Near Uses ax bx cx dx
33	mov ah, 41h
34	mov bx, 55AAh
35	mov dl, [BIOS_BootDisk] ; We check using the boot-disk
36	int 13h
37
38	IFDEF AUX_DEBUG
39	IF 0
40	DBG_TEXT_OUT_AUX 'DriveIO_CheckFor13extensions:'
41	PUSHRF
42	call DEBUG_DumpRegisters
43	;~ call AuxIO_DumpParagraph
44	;~ call AuxIO_TeletypeNL
45	mov si, offset [Scratch]
46	mov word ptr [si], 50h
47	mov ah, 48h
48	int 13h
49	call DEBUG_DumpRegisters
50	;~ call AuxIO_DumpSector
51	POPRF
52	ENDIF
53	ENDIF
54
55	jc PCCF13E_NotFound ; Error occured
56	cmp bx, 0AA55h
57	je PCCF13E_Found
58	PCCF13E_NotFound:
59	ret
60	PCCF13E_Found:
61	and cx, 1 ; Check 42h-44h,47h,48h supported
62	jz PCCF13E_NotFound ; Sig OK but no support, strange beast
63	mov byte ptr [CurIO_UseExtension], 1
64	ret
65	DriveIO_CheckFor13extensions EndP
66
67
68	; Note: Some routines set DS/ES to CS or even address via CS, even if its not
69	; needed. This was done for SECURITY. So DO NOT remove it.
70	; Its there to make sure the correct data is loaded/written to/from
71	; harddrive.
72	;
73	; IF YOU MODIFY ANYTHING IN HERE, YOU MAY EASILY BREAK YOUR HARDDRIVE!
74
75	; Will only load base-configuration, will NOT load IPT nor Hide-Config
76	; Those are originally loaded on startup and will NOT get reloaded.
77	DriveIO_LoadConfiguration Proc Near Uses ax bx cx dx es
78
79	IFDEF AUX_DEBUG
80	IF 0
81	DBG_TEXT_OUT_AUX 'DriveIO_LoadConfiguration:'
82	PUSHRF
83	;~ call DEBUG_DumpRegisters
84	;~ call AuxIO_DumpParagraph
85	;~ call AuxIO_TeletypeNL
86	POPRF
87	ENDIF
88	ENDIF
89
90	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
91	mov ax, cs
92	mov es, ax
93	mov bx, offset Configuration
94	xor dh, dh
95	mov dl, [BIOS_BootDisk] ; Disk we booted from
96	mov cx, 0037h ; Sector 55 (CHS)
97	mov ax, 0201h ; Function 02, read 1 sector...
98	int 13h
99	jnc DIOLC_NoError
100	call MBR_LoadError ; Will Abort BootUp
101
102
103	DIOLC_NoError:
104	ret
105	DriveIO_LoadConfiguration EndP
106
107	DriveIO_SaveConfiguration Proc Near Uses ax bx cx dx ds es si
108
109	IFDEF AUX_DEBUG
110	IF 0
111	DBG_TEXT_OUT_AUX 'DriveIO_SaveConfiguration:'
112	PUSHRF
113	call DEBUG_DumpRegisters
114	;~ call AuxIO_DumpParagraph
115	;~ call AuxIO_TeletypeNL
116	POPRF
117	ENDIF
118	ENDIF
119
120	mov ax, cs
121	mov ds, ax
122	mov es, ax ; Safety first (CS==DS==ES)
123	; --- Overwrite Floppy-Name with "FloppyDrive"
124	mov si, offset TXT_Floppy_Drive
125	mov di, offset PartitionTable
126	sub di, 30 ; Adjust to Floppy-Name
127	mov cx, 11
128	rep movsb
129	mov si, offset Configuration ; Calculate new checksum
130	xor bx, bx
131
132	; Changed from 5 to calculated value (not here, see compat. issue below)
133	; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
134	; Size of the ab-configuration in 512 byte sectors
135	;mov cx, (MBR_BackUpMBR - Configuration) / 200h
136
137	; AB v1.07 stores a 5 sector configuration with a 5 sector checksum.
138	; AB v1.0.8+ should stores a 7 sector configuration with a
139	; 7 sector checksum.
140	; Because 5 was hardcoded here, SET(A)BOOT v1.07 will see see an AB v1.0.8+
141	; config as corrupted, while this is not the case.
142	; So, for compatibility reasons, in v1.0.8+, the checksum stored is over
143	; 5 sectors, to be compatible with v1.07.
144	; This may change (be corrected) in future versions !
145	mov cx,5
146
147	mov dx, [CFG_CheckConfig]
148	mov [CFG_CheckConfig], bx
149	DIOSC_Loop:
150	call MBR_GetCheckOfSector
151	loop DIOSC_Loop
152	mov [CFG_CheckConfig], bx
153	; --------------------------------------------------------------------
154	; ES == CS
155	mov bx, offset Configuration
156	xor dh, dh
157	mov dl, [BIOS_BootDisk] ; Disk we booted from
158	mov cx, 0037h ; Sector 55 (CHS)
159
160	; Changed from 5 to calculated value
161	; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
162	; Size of the ab-configuration in 512 byte sectors
163	mov al, (MBR_BackUpMBR - Configuration) / 200h
164	mov ah,03h
165	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
166	int 13h
167	jnc DIOSC_NoError
168	call MBR_SaveError ; Will Abort BootUp
169	DIOSC_NoError:
170	ret
171	DriveIO_SaveConfiguration EndP
172
173	DriveIO_UpdateFloppyName Proc Near Uses bx cx dx ds si es di
174	mov ax, cs
175	mov ds, ax
176	mov es, ax
177
178	mov ah, 00h ; Function 0 - Reset Drive
179	xor dl, dl
180	int 13h
181	xor dx, dx ; Cylinder=0, Head=0
182	mov cx, 1 ; Sector=1, Drive=0
183	mov bx, offset TmpSector ; ES:BX - TmpSector
184	mov ax, 0201h ; Function 2 - Load Sector
185	int 13h
186	jnc DIOUFN_AllFine
187
188	; --- Overwrite Floppy-Name with "No Disc"
189	mov si, offset TXT_Floppy_NoDisc
190	xor ax, ax
191	DIOUFN_WriteFloppyName:
192	mov di, offset PartitionTable
193	sub di, 30 ; Adjust to Floppy-Name
194	mov cl, 11
195	rep movsb
196	ret ; AX=-1 -> GotDisc, =0 -> NoDisc
197
198	; --- Floppy found and read, data in TempSector
199	DIOUFN_AllFine:
200	mov ax, -1
201	mov si, offset TXT_Floppy_NoName
202	cmp wptr es:[bx+54], 'AF'
203	jne DIOUFN_WriteFloppyName
204	cmp wptr es:[bx+56], '1T'
205	jne DIOUFN_WriteFloppyName
206	cmp bptr es:[bx+58], '2'
207	jne DIOUFN_WriteFloppyName
208	mov si, bx
209	add si, 43 ; FAT12 - Volume Label Location
210	jmp DIOUFN_WriteFloppyName
211	DriveIO_UpdateFloppyName EndP
212
213	; =============================================================================
214	; HARDDRIVE / GENERAL ACCESS
215	; =============================================================================
216	; The following routines are used for harddisc/floppy access.
217	; The access is done via INT 13h/CHS or INT 13h/LBA.
218	; Access will be done prefered by INT 13h/CHS, because it's (I wonder!) much
219	; faster, than the LBA-method. I don't know, why LBA is so slow. Perhaps BIOS.
220	;
221	; Internal access (to AiR-BOOT) is always done via INT 13h/CHS.
222
223	DriveIO_GetHardDriveCount Proc Near Uses ds si
224	push ds
225	push si
226	push 0040h
227	pop ds
228	mov si, 0075h
229	mov dh, ds:[si] ; 40:75 -> POST: Total Harddiscs == DH
230	pop si
231	pop ds
232	mov [TotalHarddiscs], dh
233	ret
234	DriveIO_GetHardDriveCount EndP
235
236
237	; Fills our LBA-Usage table. It holds the LBA-address, where BIOS/CHS access is
238	; stopped and BIOS/LBA access is started.
239	; This is calculated by Sector*Heads. Comparing will get done with Bit 25-10
240	; on LBA sectors, so we actually divide sector number by 1024.
241	DriveIO_InitLBASwitchTable Proc Near Uses es di
242	mov di, offset LBASwitchTable
243	mov dh, [TotalHarddiscs]
244	mov dl, 80h ; First disk to process
245	DIOILUT_DriveLoop:
246	push dx
247	push di
248	mov ah, 08h
249	int 13h ; DISK - GET DRIVE PARAMETERS
250	mov ah, 0FBh ; Assume 255 heads/63 sectors, if error
251	jc DIOILUT_Error
252	and cl, 111111b ; Isolate lower 6 bits of CL -> sector count
253	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
254	;movzx ax, cl
255	mov al,cl
256	mov ah,0
257
258	mov bl, dh ; DH -> max head number
259	mul bl ; AX = Sectors*Heads
260	shl ah, 1
261	shl ah, 1 ; Shift 2 bits, so we are able to compare to
262	; bit 16-23 of the LBA address
263	DIOILUT_Error:
264	pop di
265	pop dx
266	mov bptr ds:[di], ah ; Save that value
267	inc di ; Go to next BYTE
268	inc dl ; Next disk
269	dec dh ; Decrease disks to process
270	jnz DIOILUT_DriveLoop ; Next disk if DH != 0
271	ret
272	DriveIO_InitLBASwitchTable EndP
273
274	; #########################################################################
275	; Routine: Loads partition to ExecBase and checks for validity
276	; #########################################################################
277	; Calling : bx:ax - Absolute sector
278	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
279	; Returns : Carry Set if invalid partition encountered
280	; Preserve: all registers
281	; #########################################################################
282	DriveIO_LoadPartition Proc Near Uses si
283
284	IFDEF AUX_DEBUG
285	IF 0
286	DBG_TEXT_OUT_AUX 'DriveIO_LoadPartition:'
287	PUSHRF
288	call DEBUG_DumpRegisters
289	;~ call AuxIO_DumpParagraph
290	;~ call AuxIO_TeletypeNL
291	POPRF
292	ENDIF
293	ENDIF
294
295	mov wptr cs:[CurPartition_Location+0], ax
296	mov wptr cs:[CurPartition_Location+2], bx
297	mov wptr cs:[CurPartition_Location+4], dx
298	mov wptr cs:[CurPartition_Location+6], cx ; Saves the location
299	mov si, offset [PartitionSector] ; DS:SI - ExecBase
300
301
302	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
303	call DriveIO_LoadSector
304
305	clc
306	cmp wptr [si+LocBR_Magic], 0AA55h
307	je DIOLP_Success
308	; We check, if we are scanning partitions. In that case, if CHS is not 0/0/1
309	; we will display a "bad partition table" message and halt the system.
310	cmp cx, 0001h
311	jne DIOLP_Failed
312	or dh, dh
313	jnz DIOLP_Failed
314	stc ; Set carry, so no partition table
315	DIOLP_Success:
316
317
318
319	ret
320	DIOLP_Failed:
321	jmp DriveIO_GotLoadError
322	DriveIO_LoadPartition EndP
323
324	; #########################################################################
325	; Routine: Writes a partition from ExecBase to its original sector
326	; #########################################################################
327	; Calling : none
328	; Returns : none
329	; Preserve: all registers
330	; #########################################################################
331	DriveIO_SavePartition Proc Near Uses ax bx cx dx si
332
333	IFDEF AUX_DEBUG
334	IF 0
335	DBG_TEXT_OUT_AUX 'DriveIO_SavePartition:'
336	PUSHRF
337	call DEBUG_DumpRegisters
338	;~ call AuxIO_DumpParagraph
339	;~ call AuxIO_TeletypeNL
340	POPRF
341	ENDIF
342	ENDIF
343
344	mov ax, wptr cs:[CurPartition_Location+0]
345	mov bx, wptr cs:[CurPartition_Location+2]
346	mov dx, wptr cs:[CurPartition_Location+4]
347	mov cx, wptr cs:[CurPartition_Location+6] ; Gets prev. saved location
348	mov si, offset PartitionSector ; DS:SI - ExecBase
349	cmp wptr [si+LocBR_Magic], 0AA55h ; Checks for signature, if not found
350	jne DIOSP_SevereError ; we assume a really bad error
351	call DriveIO_SaveSector
352	DIOSP_SevereError:
353	ret
354	DriveIO_SavePartition EndP
355
356
357
358	;##############################################################################
359	;# The location of LVM sectors depends on the OS/2 geometry used when the disk
360	;# was prepared. This geometry is present in the Master LVM sector, which has
361	;# already been located if it exists. All partitions, whether primary or
362	;# logical, have an entry in a partition table. For primary partitions this
363	;# table is located in the MBR, while for logical partitions this table is
364	;# located in the EBR for that logical partition. An LVM record is located
365	;# LVM_SPT-1 sectors above an MBR or EBR. The Master LVM record contains the
366	;# information for all primary partitions. For logical partitions, the LVM
367	;# sector only has one entry, because EBRs are chained. The global LVM info,
368	;# like disk-name, sectors per track, etc. is replicated between the Master
369	;# LVM sector and LVM sectors corresponding to logical partitions. This info
370	;# is kept in sync by the OS/2 LVM Engine.
371	;##############################################################################
372	;# ACTION : Attempts to load the corresponding LVM sector for a partition
373	;# ----------------------------------------------------------------------------
374	;# EFFECTS : Modifies DAP structure and fills or clears sector buffer
375	;# ----------------------------------------------------------------------------
376	;# IN : MEM - Location info is in [CurPartition_Location]
377	;# ----------------------------------------------------------------------------
378	;# OUT : CF=1 - failure, no valid LVM sector was loaded
379	;# : SI - Points to the sector buffer ([LVMSector])
380	;##############################################################################
381	DriveIO_LoadLVMSector Proc Near Uses ax bx cx dx di
382
383	IFDEF AUX_DEBUG
384	IF 0
385	DBG_TEXT_OUT_AUX 'DriveIO_LoadLVMSector:'
386	PUSHRF
387	call DEBUG_DumpRegisters
388	;~ call AuxIO_DumpSector
389	;~ call AuxIO_DumpParagraph
390	;~ call AuxIO_TeletypeNL
391	POPRF
392	ENDIF
393	ENDIF
394
395	; Clear the sector buffer
396	mov si, offset [LVMSector]
397	call ClearSectorBuffer
398
399	; Quit with CY if LVM is ignored in SETUP
400	test byte ptr [CFG_IgnoreLVM], 1 ; ZF=0 means ignore LVM
401	jnz DIOLLVMS_NoLVMSector ; Quit if so
402
403	; Load the location of the current partition being acted upon.
404	; Note that this is not the actual LBA of the partition, but the
405	; sector that has the partition table that contains the entry
406	; for the partition. In other words, for primary partitions the LBA
407	; address points to the MBR while for extended partitions it points
408	; to an EBR. In both cases the LVM sector is located LVM_SPT-1 above.
409	; Also note that the BIOS CHS values (DH and CX) below are not used,
410	; because we explicitly use LBA sector loading.
411	mov ax, wptr cs:[CurPartition_Location+0] ; LBA lo of MBR/EBR
412	mov bx, wptr cs:[CurPartition_Location+2] ; LBA hi of MBR/EBR
413	mov dx, wptr cs:[CurPartition_Location+4] ; BIOS disk num & head
414	mov cx, wptr cs:[CurPartition_Location+6] ; BIOS cyl & sec
415
416	; Do the actual loading.
417	; This is in a separate function so that LVM records can also be
418	; loaded using the MBR/EBR LBA addresses from IPT entries.
419	call DriveIO_LoadLVMSectorXBR
420	jc DIOLLVMS_NoLVMSector
421
422	; We're done, indicate success and return
423	clc
424	jmp DIOLLVMS_Done
425
426	DIOLLVMS_NoLVMSector:
427
428	; Clear the sector buffer
429	mov si, offset [LVMSector]
430	call ClearSectorBuffer
431	mov bptr [si+LocLVM_SignatureStart], 0
432
433	; Indicate no valid LVM sector was loaded
434	stc
435
436	DIOLLVMS_Done:
437
438	ret
439	DriveIO_LoadLVMSector EndP
440
441
442
443
444
445	;------------------------------------------------------------------------------
446	; Attempts to load the corresponding LVM sector for a partition
447	;------------------------------------------------------------------------------
448	; IN : AX - LBA lo of MBR or EBR
449	; : BX - LBA hi of MBR or EBR
450	; ; DL - BIOS disk number
451	; ; SI - Pointer to sector buffer (usually [LVMSec])
452	; OUT : CF=0 - A valid LVM sector was loaded
453	; NOTE : LocIPT_AbsolutePartTable and LocIPT_Drive can provide LBA and DISK
454	;------------------------------------------------------------------------------
455	DriveIO_LoadLVMSectorXBR Proc Near
456
457	IFDEF AUX_DEBUG
458	IF 0
459	DBG_TEXT_OUT_AUX 'DriveIO_LoadLVMSectorXBR:'
460	PUSHRF
461	call DEBUG_DumpRegisters
462	;~ call AuxIO_DumpSector
463	;~ call AuxIO_DumpParagraph
464	;~ call AuxIO_TeletypeNL
465	POPRF
466	ENDIF
467	ENDIF
468
469	; Save all registers
470	pusha
471
472	; Calculate the entry in the DISKINFO array for this disk,
473	; and put the LVM_SPT in DI
474	push bx
475	call DriveIO_CalcDiskInfoPointer
476	mov di, [bx+LocDISKINFO_LVM_Secs]
477	pop bx
478
479	; If the LVM_SPT is ZERO, no LVM info is present and we quit with CY
480	test di, di ; See if it is 0
481	jz DriveIO_LoadLVMSectorXBR_no_lvm ; Quit if so
482
483	; Adjust the location to point to the LVM sector
484	add ax, di ; Add the LVM sectors-per-track
485	adc bx, 0 ; Propagate LBA lo overflow to LBA hi
486	sub ax, 1 ; LVM sector is located one sector below
487	sbb bx, 0 ; Propagate borrow to LBA hi
488
489	; Load the LVM sector into sector buffer pointed to by SI
490	mov di, ds ; Segment of that buffer
491	call DriveIO_ReadSectorLBA ; Read the LVM sector
492
493	IFDEF AUX_DEBUG
494	IF 0
495	DBG_TEXT_OUT_AUX 'LVMSecLoaded'
496	PUSHRF
497	call DEBUG_DumpRegisters
498	;~ call AuxIO_DumpSector
499	mov cx, 3
500	@@:
501	call AuxIO_DumpParagraph
502	call AuxIO_TeletypeNL
503	add si, 16
504	loop @B
505	;~ call AuxIO_DumpParagraph
506	;~ call AuxIO_TeletypeNL
507	POPRF
508	ENDIF
509	ENDIF
510
511	jc DriveIO_LoadLVMSectorXBR_no_lvm ; Quit on error
512
513	; Check the validity of the LVM sector, quit with CY if invalid
514	call LVM_ValidateSector ; Check signature and CRC
515	jnc DriveIO_LoadLVMSectorXBR_no_lvm ; Quit if not valid
516
517	; We're done, indicate success and return
518	clc
519	jmp DriveIO_LoadLVMSectorXBR_done
520
521	DriveIO_LoadLVMSectorXBR_no_lvm:
522	; Indicate no valid LVM sector was loaded
523	stc
524
525	DriveIO_LoadLVMSectorXBR_done:
526	; Restore all registers
527	popa
528
529	ret
530	DriveIO_LoadLVMSectorXBR EndP
531
532
533	;##############################################################################
534	;# The location of LVM sectors depends on the OS/2 geometry used when the disk
535	;# was prepared. This geometry is present in the Master LVM sector, which has
536	;# already been located if it exists. All partitions, whether primary or
537	;# logical, have an entry in a partition table. For primary partitions this
538	;# table is located in the MBR, while for logical partitions this table is
539	;# located in the EBR for that logical partition. An LVM record is located
540	;# LVM_SPT-1 sectors above an MBR or EBR. The Master LVM record contains the
541	;# information for all primary partitions. For logical partitions, the LVM
542	;# sector only has one entry, because EBRs are chained. The global LVM info,
543	;# like disk-name, sectors per track, etc. is replicated between the Master
544	;# LVM sector and LVM sectors corresponding to logical partitions. This info
545	;# is kept in sync by the OS/2 LVM Engine.
546	;##############################################################################
547	;# ACTION : Attempts to save the corresponding LVM sector for a partition
548	;# ----------------------------------------------------------------------------
549	;# EFFECTS : Modifies DAP structure and writes LVM sector to disk
550	;# ----------------------------------------------------------------------------
551	;# IN : MEM - Location info is in [CurPartition_Location]
552	;# : SI - Pointer to sector buffer
553	;# ----------------------------------------------------------------------------
554	;# OUT : CF=1 - failure, no valid LVM sector was saved
555	;##############################################################################
556	DriveIO_SaveLVMSector Proc Near Uses ax bx cx dx di
557
558	IFDEF AUX_DEBUG
559	IF 0
560	DBG_TEXT_OUT_AUX 'DriveIO_SaveLVMSector:'
561	PUSHRF
562	call DEBUG_DumpRegisters
563	;~ call AuxIO_DumpParagraph
564	;~ call AuxIO_TeletypeNL
565	POPRF
566	ENDIF
567	ENDIF
568
569	; Quit with CY if LVM is ignored in SETUP
570	test byte ptr [CFG_IgnoreLVM], 1 ; ZF=0 means ignore LVM
571	jnz DIOSLVMS_NoLVMSector ; Quit if so
572
573	; Load the location of the current partition being acted upon.
574	; Note that this is not the actual LBA of the partition, but the
575	; sector that has the partition table that contains the entry
576	; for the partition. In other words, for primary partitions the LBA
577	; address points to the MBR while for extended partitions it points
578	; to an EBR. In both cases the LVM sector is located LVM_SPT-1 above.
579	; Also note that the BIOS CHS values (DH and CX) below are not used,
580	; because we explicitly use LBA sector loading.
581	mov ax, wptr cs:[CurPartition_Location+0] ; LBA lo of MBR/EBR
582	mov bx, wptr cs:[CurPartition_Location+2] ; LBA hi of MBR/EBR
583	mov dx, wptr cs:[CurPartition_Location+4] ; BIOS disk num & head
584	mov cx, wptr cs:[CurPartition_Location+6] ; BIOS cyl & sec
585
586	; Do the actual saving.
587	; This is in a separate function so that LVM records can also be
588	; saved using the MBR/EBR LBA addresses from IPT entries.
589	call DriveIO_SaveLVMSectorXBR
590	jc DIOSLVMS_NoLVMSector
591
592	; We're done, indicate success and return
593	clc
594	jmp DIOSLVMS_Done
595
596	DIOSLVMS_NoLVMSector:
597	; Indicate no valid LVM sector was saved
598	stc
599
600	DIOSLVMS_Done:
601	ret
602	DriveIO_SaveLVMSector EndP
603
604
605	;------------------------------------------------------------------------------
606	; Attempts to save the corresponding LVM sector for a partition
607	;------------------------------------------------------------------------------
608	; IN : AX - LBA lo of MBR or EBR
609	; : BX - LBA hi of MBR or EBR
610	; ; DL - BIOS disk number
611	; ; SI - Pointer to sector buffer (usually [LVMSec])
612	; OUT : CF=0 - A valid LVM sector was saved
613	; NOTE : LocIPT_AbsolutePartTable and LocIPT_Drive can provide LBA and DISK
614	;------------------------------------------------------------------------------
615	DriveIO_SaveLVMSectorXBR Proc Near
616
617	IFDEF AUX_DEBUG
618	IF 1
619	DBG_TEXT_OUT_AUX 'DriveIO_SaveLVMSectorXBR:'
620	PUSHRF
621	call DEBUG_DumpRegisters
622	call AuxIO_DumpSector
623	;~ call AuxIO_DumpParagraph
624	;~ call AuxIO_TeletypeNL
625	POPRF
626	ENDIF
627	ENDIF
628
629	; Save all registers
630	pusha
631
632	; Check the validity of the LVM sector, quit with CY if invalid
633	push ax ; Save LBA lo
634	call LVM_ValidateSector ; Check signature and CRC
635	pop ax ; Restore LBA lo
636	jnc DriveIO_SaveLVMSectorXBR_no_lvm ; Quit if not valid
637
638	; Calculate the entry in the DISKINFO array for this disk,
639	; and put the LVM_SPT in DI
640	push bx
641	call DriveIO_CalcDiskInfoPointer
642	mov di, [bx+LocDISKINFO_LVM_Secs]
643	pop bx
644
645	; If the LVM_SPT is ZERO, no LVM info is present and we quit with CY
646	test di, di ; See if it is 0
647	jz DriveIO_SaveLVMSectorXBR_no_lvm ; Quit if so
648
649	; Adjust the location to point to the LVM sector
650	add ax, di ; Add the LVM sectors-per-track
651	adc bx, 0 ; Propagate LBA lo overflow to LBA hi
652	sub ax, 1 ; LVM sector is located one sector below
653	sbb bx, 0 ; Propagate borrow to LBA hi
654
655	; Writing an LVM sector is always the result of modifications to a
656	; previously loaded one. So, now that we have the LBA address of the
657	; LVM sector, the one about to be overwritten should be there.
658	; If it's not, something is seriously wrong and we quit immetiately.
659	pusha ; Push our context except the flags
660	mov si, offset [Scratch] ; Sector buffer to load the LVM sector
661	call ClearSectorBuffer ; Make sure no old LVM info is present
662	mov di, ds ; Segment of buffer
663	call DriveIO_ReadSectorLBA ; Load the old LVM sector
664	call LVM_ValidateSector ; CF=1 if valid
665	cmc ; Complement for disk i/o semantics
666	popa ; Restore our context except the flags
667
668	; OOPS, There was no LVM sector there !!
669	jc DriveIO_SaveLVMSectorXBR_no_lvm
670
671	; Save the LVM sector pointed to by SI
672	mov di, ds ; Segment of that buffer
673	call DriveIO_WriteSectorLBA ; Write the LVM sector
674
675	IFDEF AUX_DEBUG
676	IF 1
677	DBG_TEXT_OUT_AUX 'LVMSecSaved'
678	PUSHRF
679	call DEBUG_DumpRegisters
680	call AuxIO_DumpSector
681	;~ call AuxIO_DumpParagraph
682	;~ call AuxIO_TeletypeNL
683	POPRF
684	ENDIF
685	ENDIF
686
687	jc DriveIO_SaveLVMSectorXBR_no_lvm ; Quit on error
688
689	; We're done, indicate success and return
690	clc
691	jmp DriveIO_SaveLVMSectorXBR_done
692
693	DriveIO_SaveLVMSectorXBR_no_lvm:
694	; Indicate no valid LVM sector was saved
695	stc
696
697	DriveIO_SaveLVMSectorXBR_done:
698	; Restore all registers
699	popa
700
701	ret
702	DriveIO_SaveLVMSectorXBR EndP
703
704
705
706	; Special error message instead of "LOAD ERROR" during partition scanning,
707	; so users will notice that something is bad with their partition table(s)
708	DriveIO_GotLoadError Proc Near
709	IFDEF AUX_DEBUG
710	IF 1
711	DBG_TEXT_OUT_AUX 'DriveIO_GotLoadError:'
712	PUSHRF
713	call DEBUG_DumpRegisters
714	;~ call AuxIO_DumpParagraph
715	;~ call AuxIO_TeletypeNL
716	POPRF
717	ENDIF
718	ENDIF
719	test byte ptr cs:[CurIO_Scanning], 1 ; Must be CS:, cause DS!=CS maybe here
720	jnz InScanMode
721	jmp MBR_LoadError
722	InScanMode:
723	mov si, offset TXT_BrokenPartitionTable
724	push cs
725	pop ds
726	call MBR_Teletype
727	mov si, offset BrokenHDD
728	sub dl, 50h ; 80h -> '0'
729	cmp dl, 39h
730	jbe DIOGLE_BelowA
731	add dl, 7 ; 3Ah -> 'A'
732	DIOGLE_BelowA:
733	mov bptr [si+5], dl
734	call MBR_Teletype
735
736	; JWasm: cannot jump to local label in other procedure.
737	; Changed to halt here.
738	;jmp MBRLE_Halt
739	DriveIO_GotLoadError_halt:
740	jmp DriveIO_GotLoadError_halt
741	DriveIO_GotLoadError EndP
742
743	; #########################################################################
744	; Routine: Loads a specified sector to DS:DI
745	; #########################################################################
746	; Calling : bx:ax - Absolute sector
747	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
748	; ds:si - Destination-Adress
749	; Returns : none
750	; Preserve: all registers
751	; #########################################################################
752	DriveIO_LoadSector Proc Near Uses ax bx cx dx ds si es di
753
754	IFDEF AUX_DEBUG
755	IF 0
756	DBG_TEXT_OUT_AUX 'DriveIO_LoadSector:'
757	PUSHRF
758	call DEBUG_DumpRegisters
759	;~ call AuxIO_DumpParagraph
760	;~ call AuxIO_TeletypeNL
761	POPRF
762	ENDIF
763	ENDIF
764
765	; Is the drive not a harddrive?
766	cmp dl, 80h
767	jb DIOLS_UseNormal
768
769	test byte ptr cs:[CurIO_UseExtension], 1
770	jz DIOLS_UseNormal
771	; Are we forced do use LBA via Setting?
772	jnz DIOLS_UseExtension
773
774	; Upper 8 bits of LBA-address set?
775	; Then use LBA (maximum boundary is 16320x16x63 = FB0400h)
776	or bh, bh
777	jnz DIOLS_UseExtension
778	; Compare Switch-Table value to bit 16-23 of LBA-address
779	mov di, dx
780	and di, 007Fh
781	cmp bptr cs:[LBASwitchTable+di], bl
782	jbe DIOLS_UseExtension
783
784	DIOLS_UseNormal:
785
786	IFDEF AUX_DEBUG
787	IF 0
788	DBG_TEXT_OUT_AUX 'DriveIO_ReadSectorCHS:'
789	PUSHRF
790	call DEBUG_DumpRegisters
791	call AuxIO_DumpParagraph
792	call AuxIO_TeletypeNL
793	POPRF
794	ENDIF
795	ENDIF
796
797	mov di, 3 ; retry count
798	DIOLS_ErrorLoop:
799	push ds
800	pop es
801	mov bx, si ; ES:BX - Destination
802	mov ax, 0201h ; Function 2 - Load Sector
803	int 13h
804	jnc DIOLS_Success
805	dec di ; decrement retry count
806	jnz DIOLS_ErrorLoop
807
808	; Sector load failed...
809	jmp DriveIO_GotLoadError
810
811	DIOLS_UseExtension:
812
813	mov di, ds ; segment for transfer address
814	call DriveIO_ReadSectorLBA ; extended read
815	jc DriveIO_GotLoadError ; halt on error
816
817	;~ push cx
818	;~ mov cs:[INT13X_DAP_NumBlocks], 1 ; Copy ONE sector
819	;~ mov wptr cs:[INT13X_DAP_Transfer+0], si
820	;~ mov cx, ds
821	;~ mov wptr cs:[INT13X_DAP_Transfer+2], cx ; Fill out Transfer Adress
822	;~ mov wptr cs:[INT13X_DAP_Absolute+0], ax
823	;~ mov wptr cs:[INT13X_DAP_Absolute+2], bx ; Fill out Absolute Sector
824	;~ push cs
825	;~ pop ds
826	;~ mov si, offset [INT13X_DAP]
827	;~ mov ah, 42h ; Extended Read
828	;~ int 13h
829	;~ pop cx
830	;~ jnc DIOLS_Success
831
832	; Sector load failed...
833	;~ jmp DriveIO_GotLoadError
834
835	DIOLS_Success:
836
837	IFDEF AUX_DEBUG
838	IF 0
839	DBG_TEXT_OUT_AUX 'sector loaded'
840	PUSHRF
841	;~ call DEBUG_DumpRegisters
842	;~ call AuxIO_DumpSector
843	mov cx, 32
844	@@:
845	call AuxIO_DumpParagraph
846	call AuxIO_TeletypeNL
847	add si, 16
848	loop @B
849	POPRF
850	ENDIF
851	ENDIF
852	ret
853	DriveIO_LoadSector EndP
854
855
856	;##############################################################################
857	;# ACTION : Loads the Master Boot Record from the specified drive into buffer
858	;# ----------------------------------------------------------------------------
859	;# EFFECTS : Modifies DAP structure and fills or clears transfer buffer
860	;# ----------------------------------------------------------------------------
861	;# IN : DL - BIOS disk number (80h,81h,etc)
862	;# : SI - Pointer to transfer buffer
863	;# ----------------------------------------------------------------------------
864	;# OUT : CF=1 - failure
865	;# : AL.0 - MBR signature present
866	;# : AL.1 - Primary partitions present
867	;# : AL.2 - Extended partitions present
868	;# : AL.3 - AiR-BOOT signature present
869	;# : AL.4:7 - Reserved, returned as 0
870	;# : AH.0:7 - Reserved, returned as 0
871	;##############################################################################
872	DriveIO_LoadMBR Proc Near uses bx cx dx si di
873
874	; Always clear the transfer buffer first
875	call ClearSectorBuffer
876
877	; Assume an invalid MBR
878	xor ax, ax
879
880	; Accept only valid harddisks
881	call DriveIO_IsValidHarddisk
882	jc DriveIO_LoadMBR_exit
883
884	; Save the address of the transfer buffer
885	mov di, si
886
887	; Read the MBR from disk
888	xor ax, ax ; LBA low
889	xor bx, bx ; LBA high
890	xor dh, dh ; Head 0
891	mov cx, 1 ; Sector 1
892	call DriveIO_LoadSector ; Read the sector from disk
893
894	; Check the loaded MBR for a signature
895	xor ax, ax ; Assume an invalid MBR
896	mov dx, [si+LocBR_Magic] ; Get word from MBR signature location
897	cmp dx, 0aa55h ; Is it the magic value ?
898	jne DriveIO_LoadMBR_exit ; Nope, no need to test anything else
899
900	; Indicate we have a MBR signature
901	or al, 01h
902
903	; Advance to the partition table
904	add si, 01beh
905
906	; Total of 4 entries to check
907	mov cx, 4
908
909	DriveIO_LoadMBR_next_entry:
910	mov dl, [si+LocBRPT_SystemID] ; Get partition-type / system-id
911	add si, 10h ; Point to next entry
912	test dl, dl ; Nothing in this one ?
913	loopz DriveIO_LoadMBR_next_entry ; Then check next entry
914
915	; All entries checked and last one was also empty, we're done
916	jz DriveIO_LoadMBR_check_ab
917
918	; Found a non-empty entry, set bits according to its type
919	cmp dl, 05h ; Old style extended container ?
920	jne @F ; Nope...
921	or al, 04h ; Yep, mark ext. container present
922	@@: cmp dl, 0fh ; New style extended container ?
923	jne @F ; Nope...
924	or al, 04h ; Yep, mark ext. container present
925	@@: or al, 02h ; Then is must be a primary
926	jcxz DriveIO_LoadMBR_check_ab ; CX=0? Then all entries processed,
927	jmp DriveIO_LoadMBR_next_entry ; otherwise check next entry
928
929	; Check if an AiR-BOOT signature is present
930	DriveIO_LoadMBR_check_ab:
931	mov si, offset [MBR_ABSig] ; Offset of AiR-BOOT signature
932	inc di ; Advance buffer pointer
933	inc di ; to AiR-BOOT signature location
934	mov cx, 7 ; Length of AiR-BOOT signature
935	cld ; Direction upwards
936	repe cmpsb ; Compare 7 bytes
937	jne DriveIO_LoadMBR_exit ; Nope, no AiR-BOOT on this disk
938	or al, 08h ; Yep, AiR-BOOT is on this disk
939	;~ jmp DriveIO_LoadMBR_exit
940
941	DriveIO_LoadMBR_exit:
942	ret
943	DriveIO_LoadMBR EndP
944
945
946	;##############################################################################
947	;# ACTION : Reads a sector from disk using INT13 extensions
948	;# ----------------------------------------------------------------------------
949	;# EFFECTS : Modifies DAP structure and fills transfer buffer
950	;# ----------------------------------------------------------------------------
951	;# IN : BX:AX - LBA address of sector
952	;# : DI:SI - SEG:OFF of transfer buffer
953	;# ----------------------------------------------------------------------------
954	;# OUT : CF=1 - failure
955	;##############################################################################
956	DriveIO_ReadSectorLBA Proc Near
957
958	IFDEF AUX_DEBUG
959	IF 0
960	DBG_TEXT_OUT_AUX 'DriveIO_ReadSectorLBA:'
961	PUSHRF
962	call DEBUG_DumpRegisters
963	call AuxIO_DumpParagraph
964	call AuxIO_TeletypeNL
965	POPRF
966	ENDIF
967	ENDIF
968
969	; Push all registers
970	pusha
971	push ds
972	push es
973
974	; One sector to read
975	mov cs:[INT13X_DAP_NumBlocks], 1
976
977	; Setup transfer address
978	mov wptr cs:[INT13X_DAP_Transfer+0], si ; offset
979	mov wptr cs:[INT13X_DAP_Transfer+2], di ; segment
980
981	; Setup LBA64 address of requested sector
982	mov wptr cs:[INT13X_DAP_Absolute+0], ax ; low word lower part
983	mov wptr cs:[INT13X_DAP_Absolute+2], bx ; high word lower part
984	mov wptr cs:[INT13X_DAP_Absolute+4], 0 ; low word upper part
985	mov wptr cs:[INT13X_DAP_Absolute+6], 0 ; high word upper part
986
987	; Address of packet
988	mov si, offset [INT13X_DAP] ; disk address packet
989
990	; Do the extended read
991	mov ah, 42h ; read function
992	int 13h ; transfer to bios
993
994	; Error occured
995	jc DriveIO_ReadSectorLBA_exit
996
997	; AH should also be zero
998	test ah, ah
999	stc
1000	jnz DriveIO_ReadSectorLBA_exit
1001
1002	; Disk read succeeded, clear CF
1003	clc
1004
1005	DriveIO_ReadSectorLBA_exit:
1006
1007	; Pop all registers
1008	pop es
1009	pop ds
1010	popa
1011
1012	ret
1013	DriveIO_ReadSectorLBA EndP
1014
1015
1016
1017	;##############################################################################
1018	;# ACTION : Writes a sector to disk using INT13 extensions
1019	;# ----------------------------------------------------------------------------
1020	;# EFFECTS : Modifies DAP structure and mofifies the disk
1021	;# ----------------------------------------------------------------------------
1022	;# IN : BX:AX - LBA address of sector
1023	;# : DI:SI - SEG:OFF of transfer buffer
1024	;# ----------------------------------------------------------------------------
1025	;# OUT : CF=1 - failure
1026	;##############################################################################
1027	DriveIO_WriteSectorLBA Proc Near
1028
1029	IFDEF AUX_DEBUG
1030	IF 0
1031	DBG_TEXT_OUT_AUX 'DriveIO_WriteSectorLBA:'
1032	PUSHRF
1033	call DEBUG_DumpRegisters
1034	call AuxIO_DumpParagraph
1035	call AuxIO_TeletypeNL
1036	POPRF
1037	ENDIF
1038	ENDIF
1039
1040	; Push all registers
1041	pusha
1042	push ds
1043	push es
1044
1045	; One sector to read
1046	mov cs:[INT13X_DAP_NumBlocks], 1
1047
1048	; Setup transfer address
1049	mov wptr cs:[INT13X_DAP_Transfer+0], si ; offset
1050	mov wptr cs:[INT13X_DAP_Transfer+2], di ; segment
1051
1052	; Setup LBA64 address of requested sector
1053	mov wptr cs:[INT13X_DAP_Absolute+0], ax ; low word lower part
1054	mov wptr cs:[INT13X_DAP_Absolute+2], bx ; high word lower part
1055	mov wptr cs:[INT13X_DAP_Absolute+4], 0 ; low word upper part
1056	mov wptr cs:[INT13X_DAP_Absolute+6], 0 ; high word upper part
1057
1058	; Address of packet
1059	mov si, offset [INT13X_DAP] ; disk address packet
1060
1061	; Do the extended write
1062	xor al, al ; no write verify
1063	mov ah, 43h ; write function
1064	int 13h ; transfer to bios
1065
1066	; Error occured
1067	jc DriveIO_WriteSectorLBA_exit
1068
1069	; AH should also be zero
1070	test ah, ah
1071	stc
1072	jnz DriveIO_WriteSectorLBA_exit
1073
1074	; Disk write succeeded, clear CF
1075	clc
1076
1077	DriveIO_WriteSectorLBA_exit:
1078
1079	; Skip the removable drive check on success
1080	jnc @F
1081
1082	; Here, CF=1 because of a failure.
1083	; This could be from a removable drive that is set to read-only,
1084	; in which case we want to fake success. What this boils down to
1085	; is that CY must be set to !IsRemovable.
1086	call DriveIO_CalcDiskInfoPointer ; Get DISKINFO pointer
1087	mov dx, [bx+LocDISKINFO_I13X_Flags] ; Get INT13X flags
1088	xor dl, 04h ; Invert 'removable' bit
1089	and dl, 04h ; Mask it out
1090	rcr dl, 3 ; Move it to CY
1091
1092	@@:
1093
1094	; Pop all registers
1095	pop es
1096	pop ds
1097	popa
1098
1099	ret
1100	DriveIO_WriteSectorLBA EndP
1101
1102
1103
1104
1105	;##############################################################################
1106	;# The Master LVM sector is not necessarily located at the end of the BIOS
1107	;# view of TRACK0. Its location depends on the OS/2 geometry active when the
1108	;# disk was partitioned. For disks < 502MiB this will most likely be LBA sector
1109	;# 62, but for disks >502MiB, extended OS/2 geometry was used and DANIS506
1110	;# uses SPT=127 for disks < 1TiB while IBMS506 uses SPT=255.
1111	;# When a huge disk < 1TiB was partitioned with IBMS506, thus using SPT=255,
1112	;# and the driver was later changed to DANIS506, DANI uses SPT=255, eventhough
1113	;# the disk < 1TiB. Whether it is DANI that is LVM aware or something else
1114	;# (maybe LVM itself) that makes DANI use the correct geometry has yet to be
1115	;# investigated.
1116	;#
1117	;# Related geometry issues are also present with USB sticks, which can get
1118	;# assigned a geometry by OS/2, which can depend if the stick was partitioned
1119	;# on foreign systems or not, or even OS/2 manufacturing a geometry that is not
1120	;# the same as the BIOS reports to us here. In both cases, fixed disks and
1121	;# removable disks, the geometry recorded in the BPB of a partition can also
1122	;# influence the geometry that OS/2 assigns. This is the case when 'preparing'
1123	;# disks for LVM use, in which case BPB values could be incorporated.
1124	;#
1125	;# What this all boils down to, is that the geometry reported by the BIOS is
1126	;# of no practical use, especially not when taking BIOS USB MSD emulation into
1127	;# account. These are among the reasons why AirBoot needs to use LBA addressing
1128	;# when handling LVM stuff and why LBA use cannot be disabled in the SETUP
1129	;# anymore.
1130	;#
1131	;# So, a Master LVM sector can be present on any sector from LBA 254 downwards
1132	;# and the only way to locate the correct one is to scan all the way down and,
1133	;# if one is found, do proper validation on its values, because it may also be
1134	;# a 'phantom' LVM sector left over from previous partition layouts.
1135	;# Most of such 'phantoms' can be filtered out by verifying the location of
1136	;# the found sector against the OS/2 geometry it specifies itself, which means
1137	;# it must be located at the LBA of the SPT-1 it specifies.
1138	;##############################################################################
1139	;# ACTION : Locates the Master LVM sector on the specified disk
1140	;# ----------------------------------------------------------------------------
1141	;# EFFECTS : Leaves [Scratch] with last sector read or cleared
1142	;# ----------------------------------------------------------------------------
1143	;# IN : DL - BIOS disk number of drive to search
1144	;# ----------------------------------------------------------------------------
1145	;# OUT : CF=1 - found
1146	;# : BX:AX - LBA address of LVM sector if found, 0 otherwise
1147	;##############################################################################
1148	DriveIO_LocateMasterLVMSector Proc Near uses cx dx si di ds es
1149
1150	IFDEF AUX_DEBUG
1151	IF 0
1152	DBG_TEXT_OUT_AUX 'DriveIO_LocateMasterLVMSector:'
1153	PUSHRF
1154	call DEBUG_DumpRegisters
1155	;~ call AuxIO_DumpSector
1156	;~ call AuxIO_DumpParagraph
1157	;~ call AuxIO_TeletypeNL
1158	POPRF
1159	ENDIF
1160	ENDIF
1161
1162	; LBA address to start scanning down from
1163	mov cx, 255
1164
1165	; Make sure ES==DS
1166	push ds
1167	pop es
1168
1169	; Because JCXZ is used, LBA sector 0 is never loaded and checked.
1170	; This is of course no problem since it is the MBR.
1171	DriveIO_LocateMasterLVMSector_next:
1172	mov si, offset [Scratch] ; Use scratch area to load sectors
1173	call ClearSectorBuffer ; Clear the scratch area
1174	clc ; Indicate Master LVM sector not found
1175	jcxz DriveIO_LocateMasterLVMSector_done
1176
1177	; Read the LBA sector specified in CX
1178	mov ax, cx ; LBA low
1179	xor bx, bx ; LBA high
1180	mov di, ds ; Segment of scratch buffer
1181	mov si, offset [Scratch] ; Offset of scratch buffer
1182	call DriveIO_ReadSectorLBA ; Read the sector
1183	lahf ; Save CF
1184	dec cx ; Prepare LBA of next sector to read
1185	sahf ; Restore CF
1186	; No need to do any LVM sector validation when read error, read next
1187	jc DriveIO_LocateMasterLVMSector_next
1188
1189	; See if the read sector has a valid signature and checksum
1190	call LVM_ValidateSector
1191
1192	; NC indicates invalid or none-LVM sector, read next
1193	jnc DriveIO_LocateMasterLVMSector_next
1194
1195	; We have found a valid LVM sector !
1196	; So it contains the OS/2 geometry for the disk.
1197	; That means this LVM sector itself must be located on the last sector
1198	; of the SPT value its OS/2 geometery specifies, which, in LBA terms
1199	; is LVM SPT-1 -- let's check that...
1200	mov bx, offset [Scratch] ; Offset of the loaded LVM sector
1201	mov al, [bx+LocLVM_Secs] ; Get the LVM SPT value (<=255)
1202	dec al ; Adjust to LVM LBA
1203	mov ah, cl ; Get next LVM LBA to search
1204	inc ah ; This one was found here
1205	cmp al, ah ; If same, LVM LBA location OK
1206	jne DriveIO_LocateMasterLVMSector_next
1207
1208	; The LVM sector we found is at the location it should be on disk,
1209	; so it's almost 99% sure this is the correct one.
1210	; Now we should compare the start and sizes of the partitions in the
1211	; MBR with the partitions specified in this LVM record.
1212	; We'll implement that later after some more research.
1213	; For now we assume this is the correct Master LVM sector for the disk.
1214	inc cx ; CX was prepared to read next, correct that
1215	stc ; Indicate we have found the Master LVM sector
1216
1217	DriveIO_LocateMasterLVMSector_done:
1218	mov bx, 0 ; A Master LVM sector always has high LBA=0
1219	mov ax, cx ; Low LBA of Master LVM sector
1220
1221	; We leave it up to the caller to store the value in a proper place
1222	ret
1223	DriveIO_LocateMasterLVMSector EndP
1224
1225
1226
1227	;
1228	; ############################################################
1229	; # Check for a valid MBR-sector to be written to disk #
1230	; ############################################################
1231	;
1232	; In
1233	; --
1234	; DL = Physical Disk
1235	; BX:CX = LBA sector
1236	; DI:SI = Source buffer
1237	;
1238	; Out
1239	; ---
1240	; CY = 1 if invalid MBR in source buffer, 0 if valid
1241	;
1242	; This routine is called when DriveIO_SaveSector attempts to write to the MBR.
1243	; It checks if the sector to be written has some sensible values in certain
1244	; places. In fact, if the sector is written to the boot-disk, the AiR-BOOT
1245	; signature should be present and the partition table should be the same
1246	; as the one at the start of the AiR-BOOT code in memory, except maybe for the
1247	; active flags.
1248	; For other disks, only the active flags are checked to be 00h or 80h and
1249	; the AA55h MBR signature.
1250	;
1251	DriveIO_ProtectMBR Proc Near
1252	pusha ; Push all registers
1253	push es ; Push ES because we need it for string instructions
1254	push cs ; Make ES point...
1255	pop es ; to CS
1256
1257	; Save the pointer to the sector to write in BX
1258	mov bx,si
1259
1260	;
1261	; If the sector to be written is not the boot-disk, then skip
1262	; checking the AiR-BOOT MBR.
1263	;
1264	cmp dl, [BIOS_BootDisk]
1265	jne DriveIO_ProtectMBR_is_not_bootdisk
1266
1267	;
1268	; The boot-disk is accessed so the sector to be written must be
1269	; the AiR-BOOT MBR. This is the same as the first 512 bytes
1270	; relocated to 8000:0000 and this the start of the AB-code.
1271	;
1272	mov si,bx ; Get pointer to sector to write
1273	xor di,di ; Point DI to start of AB-code (MBR)
1274	mov cx, offset [MBR_PartTable] ; Bytes upto P-table must be same
1275	cld ; Compare upwards
1276	repe cmpsb ; Compare upto P-table
1277
1278	; If not the same this is not the an AiR-BOOT boot-disk MBR !
1279	jne DriveIO_ProtectMBR_not_valid_MBR ; SEVERE ERROR !
1280
1281	; Continue with signature check
1282	jmp DriveIO_ProtectMBR_check_signature
1283
1284
1285	;
1286	; The disk is not the boot-disk so we don't know what kind of MBR is on it.
1287	; Some sanity checks should be here.
1288	;
1289	DriveIO_ProtectMBR_is_not_bootdisk:
1290
1291	;
1292	; sanity checks...
1293	;
1294
1295	; Continue with signature check
1296	jmp DriveIO_ProtectMBR_check_signature
1297
1298
1299	DriveIO_ProtectMBR_check_signature:
1300	; See if the sector to write contains a valid signature
1301	mov si,bx ; Get pointer to sector to write
1302	mov di, offset [MBR_Sig] ; Offset to MBR signature
1303	add si,di ; Make SI point to it in sec to write
1304	lodsw ; Load it
1305	cmp ax,0aa55h ; See if it is valid
1306
1307	; If no signature this cannot be a valid MBR !
1308	jne DriveIO_ProtectMBR_not_valid_MBR ; SEVERE ERROR !
1309
1310
1311	;
1312	; The sector to be written seems to be valid.
1313	; Set CY=0 to indicate a valid MBR.
1314	;
1315	DriveIO_ProtectMBR_is_valid_MBR:
1316	clc
1317	jmp DriveIO_ProtectMBR_end
1318
1319	;
1320	; Something is terribly wrong; a non-MBR sector seems about to be written.
1321	; Set CY=1 and let the calling code handle this situation.
1322	;
1323	DriveIO_ProtectMBR_not_valid_MBR:
1324	stc
1325	jmp DriveIO_ProtectMBR_end
1326
1327	;
1328	; Return to the caller with no registers modyfied except FLAGS.
1329	;
1330	DriveIO_ProtectMBR_end:
1331	pop es
1332	popa
1333	ret
1334	DriveIO_ProtectMBR Endp
1335
1336
1337
1338	; #########################################################################
1339	; Routine: Checks if the MBR is addressed by either CHS or LBA
1340	; #########################################################################
1341	; Calling : bx:ax - Absolute sector
1342	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
1343	; Returns : ZF=1 if MBR is addressed, else ZF=0
1344	; Preserve: all registers
1345	; #########################################################################
1346	DriveIO_MBR_Addressed Proc
1347	push ax
1348	push bx
1349
1350	or bx,ax ; Results in 0 in BX if MBR is addressed by LBA
1351	jz DriveIO_MBR_Addressed_done
1352
1353	mov ax,cx ; Results in 1 in AX if CYL 0, SEC 1 is addressed
1354	add al,dh ; Results in 1 in AX if HEAD 0 is addressed
1355	dec ax ; Results in 0 in AX if MBR is addressed by CHS
1356
1357	DriveIO_MBR_Addressed_done:
1358	pop bx
1359	pop ax
1360	ret
1361	DriveIO_MBR_Addressed EndP
1362
1363
1364
1365
1366	; #########################################################################
1367	; Routine: Writes DS:SI to a specified sector
1368	; #########################################################################
1369	; Calling : bx:ax - Absolute sector
1370	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
1371	; ds:si - Source-Adress
1372	; Returns : none
1373	; Preserve: all registers
1374	; #########################################################################
1375	DriveIO_SaveSector Proc Near Uses ax bx cx dx ds si es di
1376
1377	IFDEF AUX_DEBUG
1378	IF 0
1379	DBG_TEXT_OUT_AUX 'DriveIO_SaveSector:'
1380	PUSHRF
1381	call DEBUG_DumpRegisters
1382	;~ call AuxIO_DumpParagraph
1383	;~ call AuxIO_TeletypeNL
1384	POPRF
1385	ENDIF
1386	ENDIF
1387
1388
1389	;!
1390	;! DEBUG_BLOCK
1391	;! Force write to LBA0 to test interception routine.
1392	;! Do NOT enable unless you are debugging, will overwrite MBR !
1393	;!
1394	IFDEF AUX_DEBUG
1395	IF 0
1396	pushf
1397	pusha
1398	xor ax,ax
1399	xor bx,bx
1400	xor cx,cx
1401	inc cx
1402	xor dh,dh
1403	popa
1404	popf
1405	ENDIF
1406	ENDIF
1407
1408	;
1409	; Check if the MBR is the destination for the write.
1410	; ZF=1 if so.
1411	;
1412	call DriveIO_MBR_Addressed
1413	jnz DriveIO_SaveSector_continue_write
1414
1415
1416	; MBR is addressed, check the sector that is requested to be written.
1417	; For the bootdisk it should contain the AiR-BOOT signature, valid
1418	; partition-table entries and the AA55h signature.
1419	; If not, something is terribly wrong in some piece of the AB code.
1420	; For any other disk (80h+) at least a valid partition table should
1421	; be present together with the AA55h signature.
1422	call DriveIO_ProtectMBR
1423	jnc DriveIO_SaveSector_continue_write
1424
1425
1426	;
1427	; WE HAVE A SEVERE ERROR CONDITION !
1428	; SOME AB CODE TRIES TO WRITE A NON-MBR TO THE DISK !
1429	; ASK THE USER TO REPORT THIS !
1430	; HALT THE SYSTEM !
1431	;
1432
1433	; Show error-box
1434	mov cx, 0C04h
1435	mov si, offset NonMBRwrite
1436	call SETUP_ShowErrorBox
1437	mov cx, 0C04h
1438	mov si, offset NonMBRwrite_rep
1439	call SETUP_ShowErrorBox
1440
1441
1442	IFDEF AUX_DEBUG
1443	IF 0
1444	pushf
1445	pusha
1446	mov si, offset [NonMBRwrite]
1447	call AuxIO_TeletypeNL
1448	call AuxIO_Print
1449	call AuxIO_TeletypeNL
1450	popa
1451	popf
1452	ENDIF
1453	ENDIF
1454
1455	; Show popup and halt the system.
1456	jmp HaltSystem
1457
1458
1459
1460	;
1461	; Continue the write if not MBR sector or MBR to write is validated.
1462	;
1463	DriveIO_SaveSector_continue_write:
1464	test byte ptr cs:[CurIO_UseExtension], 1
1465	jz DIOSS_UseNormal
1466	; Are we forced do use LBA via Setting?
1467	; Always use INT13X on v1.0.8+.
1468	;~ test byte ptr cs:[CFG_ForceLBAUsage], 1
1469	;~ jnz DIOSS_UseExtension
1470	jmp DIOSS_UseExtension
1471	; Is the drive not a harddrive?
1472	cmp dl, 80h
1473	jb DIOSS_UseNormal
1474	; Upper 8 bits of LBA-address set? -> Use LBA (maximum boundary is FB0400h)
1475	or bh, bh
1476	jnz DIOSS_UseExtension
1477	; Compare Switch-Table value to bit 16-23 of LBA-address
1478	mov di, dx
1479	and di, 007Fh
1480	cmp bptr cs:[LBASwitchTable+di], bl
1481	jbe DIOSS_UseExtension
1482
1483	DIOSS_UseNormal:
1484
1485	IFDEF AUX_DEBUG
1486	IF 0
1487	DBG_TEXT_OUT_AUX 'DriveIO_WriteSectorCHS:'
1488	PUSHRF
1489	call DEBUG_DumpRegisters
1490	call AuxIO_DumpParagraph
1491	call AuxIO_TeletypeNL
1492	POPRF
1493	ENDIF
1494	ENDIF
1495
1496	mov di, 3 ; retry count
1497	DIOSS_ErrorLoop:
1498	push ds
1499	pop es
1500	mov bx, si ; ES:BX - Destination
1501	mov ax, 0301h ; Function 3 - Write Sector
1502	int 13h
1503	jnc DIOSS_Success
1504	dec di ; decrement retry count
1505	jnz DIOSS_ErrorLoop
1506	call MBR_SaveError
1507
1508	DIOSS_UseExtension:
1509
1510	mov di, ds ; segment for transfer address
1511	call DriveIO_WriteSectorLBA ; extended write
1512	jc MBR_SaveError ; halt on error
1513
1514	;~ push cx
1515	;~ mov cs:[INT13X_DAP_NumBlocks], 1 ; Copy ONE sector
1516	;~ mov wptr cs:[INT13X_DAP_Transfer+0], si
1517	;~ mov cx, ds
1518	;~ mov wptr cs:[INT13X_DAP_Transfer+2], cx ; Fill out Transfer Adress
1519	;~ mov wptr cs:[INT13X_DAP_Absolute+0], ax
1520	;~ mov wptr cs:[INT13X_DAP_Absolute+2], bx ; Fill out Absolute Sector
1521	;~ push cs
1522	;~ pop ds
1523	;~ mov si, offset [INT13X_DAP]
1524	;~ mov ax, 4300h ; Extended Write (No Verify)
1525	;~ int 13h
1526	;~ pop cx
1527	;~ jnc DIOSS_Success
1528	;~ call MBR_SaveError
1529
1530	DIOSS_Success:
1531	ret
1532	DriveIO_SaveSector EndP
1533
1534
1535
1536
1537	;##############################################################################
1538	;# When a disk has a Master LVM sector, it means it has been prepared for use
1539	;# by OS/2 and contains important information about how OS/2 views its geometry
1540	;# and other disk related properties. This function assumes the LBA address
1541	;# of the Master LVM sector has already been located and simply loads the
1542	;# sector into [LVMSector].
1543	;#
1544	;# Note that because this is an operation similar to the regular loading of
1545	;# sectors, the disk I/O semantics are used here. This means CF=0 when an LVM
1546	;# sector is successfully loaded and CF=1 otherwise.
1547	;##############################################################################
1548	;# ACTION : Loads the Master LVM sector if one exists
1549	;# ----------------------------------------------------------------------------
1550	;# EFFECTS : Modifies DAP structure and [LVMSector]
1551	;# ----------------------------------------------------------------------------
1552	;# IN : DL - BIOS disk number (80h,81h,etc)
1553	;# ----------------------------------------------------------------------------
1554	;# OUT : CF=0 - Valid Master LVM sector found and loaded
1555	;##############################################################################
1556	DriveIO_LoadMasterLVMSector Proc Near
1557
1558	IFDEF AUX_DEBUG
1559	IF 0
1560	DBG_TEXT_OUT_AUX 'DriveIO_LoadMasterLVMSector:'
1561	PUSHRF
1562	;~ call DEBUG_DumpRegisters
1563	;~ call AuxIO_DumpParagraph
1564	;~ call AuxIO_TeletypeNL
1565	POPRF
1566	ENDIF
1567	ENDIF
1568
1569	; Save all registers
1570	pusha
1571
1572	; Check if BIOS disk number is valid
1573	call DriveIO_IsValidHarddisk
1574	jc DriveIO_LoadMasterLVMSector_error
1575
1576	; Calculate the entry in the DISKINFO array for this disk
1577	call DriveIO_CalcDiskInfoPointer
1578
1579	; Save the entry for later recalls
1580	mov bp, bx
1581
1582	; Get the LBA address of the Master LVM sector
1583	mov ax, [bx+LocDISKINFO_LVM_MasterLBA+00h]
1584	mov bx, [bx+LocDISKINFO_LVM_MasterLBA+02h]
1585
1586	; LBA of Master LVM sector cannot be 0, so none was found during
1587	; the gathering of disk information.
1588	mov cx, ax
1589	or cx, bx
1590	jz DriveIO_LoadMasterLVMSector_error
1591
1592	; Load it into [LVMSector]
1593	mov di, ds
1594	mov si, offset [LVMSector]
1595	call DriveIO_ReadSectorLBA
1596	jc DriveIO_LoadMasterLVMSector_error
1597
1598	; Validate the Master LVM sector
1599	call LVM_ValidateSector
1600
1601	; Complement success indicator to conform to semantics of this function
1602	cmc
1603
1604	; Master LVM sector was valid and is now loaded in [LVMSector]
1605	jnc DriveIO_LoadMasterLVMSector_ret
1606
1607	DriveIO_LoadMasterLVMSector_error:
1608
1609	; Clear the sector buffer for safety reasons
1610	mov si, offset [LVMSector]
1611	call ClearSectorBuffer
1612
1613	; Indicate no Master LVM sector loaded
1614	stc
1615
1616	DriveIO_LoadMasterLVMSector_ret:
1617
1618	; Restore all registers
1619	popa
1620
1621	ret
1622	DriveIO_LoadMasterLVMSector Endp
1623
1624
1625
1626
1627	;##############################################################################
1628	;# There is much information to know about the connected disks.
1629	;# We also want this information clustered per disk and available before
1630	;# further disk and partition scanning takes place.
1631	;# This function gathers such information like INT13, INT13X, MBR, LVM, more.
1632	;# Especially important is the LVM information, because that contains the
1633	;# geometry OS/2 uses to access the disk. Other important information is the
1634	;# presence of valid MBRs, logical partitions and whatnot.
1635	;# This function gathers such information and stores it in a DISKINFO structure
1636	;# for which an instance exists for every disk found.
1637	;##############################################################################
1638	;# ACTION : Gather disk information and store this in the BSS
1639	;# ----------------------------------------------------------------------------
1640	;# EFFECTS : Modifies DAP structure and the buffers it uses, fills DISKINFO[n]
1641	;# ----------------------------------------------------------------------------
1642	;# IN : DL - BIOS disk number (80h,81h,etc)
1643	;# ----------------------------------------------------------------------------
1644	;# OUT : CF=1 - failure
1645	;##############################################################################
1646	DriveIO_GatherDiskInfo Proc Near
1647
1648	IFDEF AUX_DEBUG
1649	IF 0
1650	DBG_TEXT_OUT_AUX 'DriveIO_GatherDiskInfo:'
1651	PUSHRF
1652	call DEBUG_DumpRegisters
1653	;~ call AuxIO_DumpParagraph
1654	;~ call AuxIO_TeletypeNL
1655	POPRF
1656	ENDIF
1657	ENDIF
1658
1659	; Push all registers we use
1660	pusha
1661	push ds
1662	push es
1663
1664	; Make sure ES=DS
1665	push ds
1666	pop es
1667
1668	; Check if BIOS disk number is valid
1669	call DriveIO_IsValidHarddisk
1670	jc DriveIO_GatherDiskInfo_error
1671
1672	; Calculate the entry in the DISKINFO array for this disk
1673	call DriveIO_CalcDiskInfoPointer
1674
1675	; Save the entry for later recalls
1676	mov bp, bx
1677
1678	; Store the BIOS disk number in the structure
1679	mov [bx+LocDISKINFO_DiskNum], dl
1680
1681	; ------------------------------------------------------------------- [ INT13 ]
1682
1683	; Get BIOS Disk Parameters (legacy method)
1684	mov ah, 08h ; Get Disk Parameters
1685	int 13h ; Call BIOS
1686
1687	; CF=1 or AH!=0 indicates error
1688	jc DriveIO_GatherDiskInfo_error
1689	test ah, ah
1690	jnz DriveIO_GatherDiskInfo_error
1691
1692	; Recall DISKINFO entry
1693	mov bx, bp
1694
1695	; Store SPT (WORD)
1696	xor ah, ah ; Zero extend SPT to 16 bits
1697	mov al, cl ; Hi 2 bits max cyl and max sec
1698	and al, 3fh ; Mask max sec (1-based)
1699	mov [bx+LocDISKINFO_I13_Secs], ax ; Store SPT
1700
1701	; Store HEADS (WORD)
1702	xor dl, dl ; Zero extend HEADS to 16 bits
1703	xchg dl, dh ; Get max head (0-based)
1704	inc dx ; Head count
1705	mov [bx+LocDISKINFO_I13_Heads], dx ; Store HEADS
1706
1707	; Store CYLS (WORD)
1708	shr cl, 6 ; Hi 2 bits of max cyl to 1:0
1709	xchg cl, ch ; Max cyl (0-based)
1710	inc cx ; Cyl count
1711	mov [bx+LocDISKINFO_I13_Cyls], cx ; Store CYLS
1712
1713	; Recall BIOS disk number
1714	mov dl, [bx+LocDISKINFO_DiskNum]
1715
1716	; ------------------------------------------------------------------ [ INT13X ]
1717
1718	; Get BIOS Disk Parameters (extended method)
1719	mov si, offset [Scratch] ; Buffer to return disk info
1720	mov ax, 80h ; Size of buffer
1721	mov [si], ax ; Store it in first word
1722	mov ah, 48h ; Get Extended Disk Parameters
1723	int 13h ; Call BIOS
1724
1725	; CF=1 or AH!=0 indicates error
1726	jc DriveIO_GatherDiskInfo_error
1727	test ah, ah
1728	jnz DriveIO_GatherDiskInfo_error
1729
1730	; Store flags (WORD)
1731	cld ; Direction up
1732	lodsw ; Buffersize, discard
1733	lodsw ; Flags (CHS valid etc)
1734	mov [bx+LocDISKINFO_I13X_Flags], ax ; Store them
1735
1736	; Store CYLS (DWORD)
1737	lodsw ; Cyl count low
1738	mov [bx+LocDISKINFO_I13X_Cyls+00h], ax ; Store CYLS low
1739	lodsw ; Cyl count high
1740	mov [bx+LocDISKINFO_I13X_Cyls+02h], ax ; Store CYLS high
1741
1742	; Store HEADS (DWORD)
1743	lodsw ; Head count low
1744	mov [bx+LocDISKINFO_I13X_Heads+00h], ax ; Store HEADS low
1745	lodsw ; Head count high
1746	mov [bx+LocDISKINFO_I13X_Heads+02h], ax ; Store HEADS high
1747
1748	; Store SPT (DWORD)
1749	lodsw ; Secs per track low
1750	mov [bx+LocDISKINFO_I13X_Secs+00h], ax ; Store SPT low
1751	lodsw ; Secs per track high
1752	mov [bx+LocDISKINFO_I13X_Secs+02h], ax ; Store SPT high
1753
1754	; Store total LBA sectors (QWORD)
1755	lea di, [bx+LocDISKINFO_I13X_SecsLBA]
1756	mov cx, 4
1757	rep movsw
1758
1759	; Store sector size (WORD)
1760	lodsw
1761	mov [bx+LocDISKINFO_I13X_SecSize], ax
1762
1763	; Store bus name (4 bytes, space padded, v3.0+)
1764	lea si, [Scratch+24h]
1765	lea di, [bx+LocDISKINFO_I13X_HostBus]
1766	movsw
1767	movsw
1768
1769	; Store interface name (8 bytes, space padded, v3.0+)
1770	lea di, [bx+LocDISKINFO_I13X_Interface]
1771	mov cx, 4
1772	rep movsw
1773
1774	; Should gather some more INT13X info here,
1775	; like maybe Advanced Format stuff or so.
1776	; We'll investigate that at a later time.
1777
1778	; --------------------------------------------------------------------- [ MBR ]
1779
1780	; Load the MBR
1781	mov si, offset [TmpSector]
1782	call DriveIO_LoadMBR
1783
1784	; Store MBR flags (valid sig, partitions present, airboot installed)
1785	mov [bx+LocDISKINFO_MbrFlags], al
1786
1787	; Recall BIOS disk number
1788	mov dl, [bx+LocDISKINFO_DiskNum]
1789
1790	; --------------------------------------------------------------------- [ LVM ]
1791
1792	; Locate the Master LVM sector, if any
1793	call DriveIO_LocateMasterLVMSector
1794
1795	; Save Master LVM sector LBA high
1796	mov cx, bx
1797
1798	; Recall DISKINFO entry
1799	mov bx, bp
1800
1801	; Store Master LVM sector LBA
1802	mov [bx+LocDISKINFO_LVM_MasterLBA+00h], ax
1803	mov [bx+LocDISKINFO_LVM_MasterLBA+02h], cx
1804
1805	; No Master LVM sector found, so skip storing LVM info for this disk
1806	jnc DriveIO_GatherDiskInfo_no_master_lvm
1807
1808	; Load the Master LVM sector into [LVMSector]
1809	call DriveIO_LoadMasterLVMSector
1810
1811	; No valid Master LVM sector, so skip storing LVM info for this disk
1812	jc DriveIO_GatherDiskInfo_no_master_lvm
1813
1814	; A valid Master LVM sector has been loaded into [LVMSector]
1815	mov si, offset [LVMSector]
1816
1817	; Get the number of sectors per track (OS/2 geometry)
1818	mov ax, [si+LocLVM_Secs+00h]
1819	mov cx, [si+LocLVM_Secs+02h]
1820
1821	; Store it
1822	mov [bx+LocDISKINFO_LVM_Secs+00h], ax
1823	mov [bx+LocDISKINFO_LVM_Secs+02h], cx
1824
1825	; Get the number of heads (OS/2 geometry)
1826	mov ax, [si+LocLVM_Heads+00h]
1827	mov cx, [si+LocLVM_Heads+02h]
1828
1829	; Store it
1830	mov [bx+LocDISKINFO_LVM_Heads+00h], ax
1831	mov [bx+LocDISKINFO_LVM_Heads+02h], cx
1832
1833	; Should gather some more LVM info here,
1834	; like OS/2 extended geometry and other flags.
1835	; We'll implement that at a later time.
1836
1837	DriveIO_GatherDiskInfo_no_master_lvm:
1838
1839	; When no Master LVM sector was found,
1840	; the LVM info in the DISKINFO structure for the disk
1841	; will be ZERO because the area was cleared in PRECRAP.
1842
1843	; Indicate success
1844	clc
1845
1846	jmp DriveIO_GatherDiskInfo_ret
1847
1848	DriveIO_GatherDiskInfo_error:
1849	stc
1850	DriveIO_GatherDiskInfo_ret:
1851
1852
1853	IFDEF AUX_DEBUG
1854	IF 0
1855	DBG_TEXT_OUT_AUX '[DISKINFO]'
1856	PUSHRF
1857	call DEBUG_DumpRegisters
1858	;~ call AuxIO_DumpParagraph
1859	;~ call AuxIO_TeletypeNL
1860	mov si, bp
1861	mov cx, 4
1862	@@:
1863	call AuxIO_DumpParagraph
1864	call AuxIO_TeletypeNL
1865	add si, 16
1866	loop @B
1867	mov si, offset [Scratch]
1868	mov cx, 4
1869	@@:
1870	call AuxIO_DumpParagraph
1871	call AuxIO_TeletypeNL
1872	add si, 16
1873	loop @B
1874	mov si, offset [LVMSector]
1875	mov cx, 7
1876	@@:
1877	call AuxIO_DumpParagraph
1878	call AuxIO_TeletypeNL
1879	add si, 16
1880	loop @B
1881	POPRF
1882	ENDIF
1883	ENDIF
1884
1885	; Restore registers
1886	pop es
1887	pop ds
1888	popa
1889
1890	ret
1891	DriveIO_GatherDiskInfo EndP
1892
1893	;------------------------------------------------------------------------------
1894	; Scan all disks to gather information
1895	;------------------------------------------------------------------------------
1896	; IN : None
1897	; OUT : CF=1 - some failure occured
1898	; : ZF=1 - no harddisks
1899	; NOTE : This does the preliminary gathering of disk information
1900	;------------------------------------------------------------------------------
1901	DriveIO_ScanDisks Proc Near
1902
1903	IFDEF AUX_DEBUG
1904	IF 0
1905	DBG_TEXT_OUT_AUX 'DriveIO_ScanDisks:'
1906	PUSHRF
1907	call DEBUG_DumpRegisters
1908	;~ call AuxIO_DumpParagraph
1909	;~ call AuxIO_TeletypeNL
1910	POPRF
1911	ENDIF
1912	ENDIF
1913
1914	; Save all registers
1915	pusha
1916
1917	; Get number of disks in DH
1918	call DriveIO_GetHardDriveCount
1919
1920	; Check if there are any disks to scan
1921	xor cx, cx ; Prepare 16-bit counter
1922	mov cl, dh ; Number of disks now in CX
1923	jcxz DriveIO_ScanDisks_end ; Quit if no disks
1924
1925	; Scan disks from 80h upward
1926	mov dl, 80h ; BIOS number of first disk
1927	DriveIO_ScanDisks_next:
1928	call DriveIO_GatherDiskInfo ; Gather info for this disk
1929	jc DriveIO_ScanDisks_end ; Quit if some error occured
1930	inc dl ; Advance to next disk
1931	loop DriveIO_ScanDisks_next ; Scan next disk if there is one
1932	test dl, dl ; Set ZF=0
1933	clc ; Indicate success
1934
1935	DriveIO_ScanDisks_end:
1936	; Restore all registers
1937	popa
1938
1939	ret
1940	DriveIO_ScanDisks EndP
1941
1942	;------------------------------------------------------------------------------
1943	; Calculate pointer to entry in DISKINFO structure
1944	;------------------------------------------------------------------------------
1945	; IN : DL BIOS disk number (80h etc)
1946	; OUT : BX Pointer to entry
1947	; NOTE : BIOS disk number must be valid
1948	;------------------------------------------------------------------------------
1949	DriveIO_CalcDiskInfoPointer Proc Near
1950	xchg bx, ax ; AX is used for calculation
1951	mov al, DISKINFO_Size ; Size of DISKINFO structure
1952	mov ah, dl ; BIOS disk number
1953	sub ah, 80h ; Now 0-based index
1954	mul ah ; Now offset into DISKINFO array
1955	add ax, offset [DiskInformation] ; Base of DISKINFO array
1956	xchg bx, ax ; BX now points to entry for disk
1957	ret
1958	DriveIO_CalcDiskInfoPointer EndP
1959
1960	;------------------------------------------------------------------------------
1961	; Check if the BIOS disk number in DL is a harddisk and in range
1962	;------------------------------------------------------------------------------
1963	; IN : DL BIOS disk number (80h etc)
1964	; OUT : CF=1 if invalid disk number or out of range
1965	; NOTE : Only modifies flags
1966	;------------------------------------------------------------------------------
1967	DriveIO_IsValidHarddisk Proc Near Uses dx
1968	cmp dl, 80h ; BIOS disk number must be at least 80h
1969	jb @F ; Not a harddisk, exit with CY
1970	mov dh, dl ; Save to do compare
1971	sub dh, 80h ; Now 0 based disk number
1972	inc dh ; Now 1 based disk number
1973	cmp [TotalHarddiscs], dh ; Out of range, exit with CY
1974	@@: ret
1975	DriveIO_IsValidHarddisk EndP
1976
1977
1978	; Values for sectors per track table corresponding to DriveIO_IsHugeDrive return value.
1979	;~ secs_per_track_table db 63,127,255,255,255,255
1980
1981	;~ db_lmlvm db 'Load Master LVM -- disk: ',0

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