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DRIVEIO.ASM@ 51

Last change on this file since 51 was 51, checked in by Ben Rietbroek, 11 years ago

AiR-BOOT v1.0.8-rc3 build-20120909 [2012-09-10]

With Git one can easily hop-skip-and-jump between branches.
So I use Git for my local repos and make use of this easy branching.
Because SVN can only handle lineair history, these branches had to be
rebased before committing them to Netlabs. So, this commit contains a
multitude of changes which makes it a bit hairy.

New

o Display LVM drive-letters in the main menu

A populair request was to show drive-letter information in the menu.
Drive-letters however, are OS specific and AiR-BOOT cannot
accurately predict what drive-letter other operating systems would
assign to what partition. eCS LVM drive-letters however are stored
in the LVM-record and can thus be displayed.

o Added 'Show LVM Drive Letters' option in SETUP/BASIC

This will toggle the display of LVM drive-letters in the main menu.
By default this option is enabled.

o Show popup message when BIOS INT13X extensions are not available

The system is halted.

o Show 'DEL to Power Off' in the bottom left corner

This tries to power-off the system, but it may not work for you.

o Simple interactive debugger

Outputs to the serial port with a few one-letter commands to dump
internal tables and state. (Only available in debug builds)

o Enhanced drive-letter feature

Enable multiple eCS installations using the same drive-letter.
This makes it possible to clone a system with the command
'XCOPY /h /o /t /s /e /r /v /e' to another drive and have that boot
from the same drive-letter.
(Or installing to the same drive by hiding the other system)

Changes

o Reduced MBR protection-image from 1024 to 768 bytes

Luckily the MBR Protection Image code does not exceed 768 bytes,
so that gives us another 256 bytes of precious code-space.
Now the non-EN versions are happy again.
Note that the alignment for the image changed from 512 to 256 bytes.
MBR-PROT.ASM, FIXCODE.C, PARTMAIN.ASM and AIR-BOOT.ASM have been
adjusted for this change.
The fight for code-space continues...

o Updating from v1.06 now also copies over drive-letters

When the user has forced drive-letters in v1.06 these will be copied
over to the v1.0.8 configuration when upgrading.
Because the drive-letter feature is broken in v1.07,
the drive-letter table does not get copied over when upgrading
from v1.07.

o Made FX-code optional to compile in

The FX-code supplies the shifting screen-effects when 'Cooper Bars'
is enabled in the setup. With the current enhancements made however,
there is a continuous lack of code-space, especially when debug-code
is included during development. The FX-code occupies some
1200 bytes, a space that can be put to better use. Therefore the
inclusion of the FX-code has been made conditional to make room for
either debugging or future new features.

o Also rewrite PBR on HPFS

Earlier, a fix was made to write a modified PBR back in case JFS was
used. This was done to enable the drive-letter feature on JFS, since
the PBR JFS-bootcode does not use the supplied PBR in memory.
With the enhancements in the drive-letter feature, the HPFS PBR
needs to be updated on disk also, to cope with zero drive-letters in
the HPFS PBR. This potentially fixes a missing drive-letter in the
PBR when the system is restored from an archive. You might need the
drive-letter feature to force the correct drive-letter on the first
boot, after which the feature can be disabled.

o Added extra MBR protection

When AiR-BOOT is active, it is only AiR-BOOT that writes to the MBR.
To protect the MBR from programming errors, like the one below,
any write to the MBR is now checked for validity.
In essence this is protecting your MBR from bad programming done
by me...

Fixes

o Fixed a minor bug with displaying LVM drive-letters

When more partitions that can be displayed were present, scrolling
the menu would not scroll the drive-letter. Fixed.

o Fixed a bug with regard to the drive-letter feature

When partitions were deleted, and some partitions above the deleted
partition(s) had a drive-letter forced, these partitions would lose
this assignment. This bug is also present in v1.06.

Note

The AIRBOOT.HIS file mentions a DOCU directory with the AiR-BOOT
documentation etc. However, this is not present in this commit and
will be provided at a later time.

File size: 51.1 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	; 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 0 - 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
209
210	; Adjusts BX:AX / CX:DX to meet LVM sector location
211	; BX:AX / CX:DX point to MBR or EBR !
212	; Destroys SI
213	; Rousseau: Enhanced to handle sector-numbers 127 and 255 besides 63 for LVM-info sectors.
214	; Ugly, need to cleanup.
215	DriveIO_LVMAdjustToInfoSector Proc Near
216	push cx ; Save Cyl/Sec part
217	xor ch,ch ; Clear low Cyl part
218	and cl,63 ; Clear high Cyl part
219	push bx ; We need BX...
220	push dx ; and DX temoraily
221	mov bx,offset [TrueSecs] ; Offset of sector table
222	xor dh,dh ; Clear DH because we use DL as index
223	and dl,01111111b ; Remove high bit of BIOS disk-nr
224	shl dx,2 ; Index to DWORD table
225	add bx,dx ; Point to TrueSecs for this disk
226	mov si,[bx] ; Get SPT for this disk
227	pop dx ; Restore DX...
228	pop bx ; and BX
229	;~ sub si,cx ; Adjust offset !! INCORRECT FOR LBA (TP CX != 0 !!)
230	dec si
231	pop cx ; Restore Cyl/Sec part
232	add ax,si ; Add offset to low part...
233	adc bx,0 ; and high part of LBA address
234	or cl,63 ; Adjust CHS part !FIX ME for > 63! !! FIX HUGE DRIVE !!
235	ret
236
237
238	;;jmp bliep
239	;; pusha
240
241	;; push dx
242	;; push bx
243	;; xor dh,dh
244	;; and dl,01111111b
245	;; shl dx,1
246	;; shl dx,1
247	;; mov bx, offset [TrueSecs]
248	;; add bx,dx
249	;; mov ax,word ptr [bx]
250	;; pop bx
251	;; pop dx
252
253
254	;
255	; AX now contains LVM secs
256	;
257
258
259	;; pusha
260	;; push dx
261	;; ; Location of extended position
262	;; mov dx,word ptr [ExtendedAbsPos+02]
263	;; mov ax,word ptr [ExtendedAbsPos+00]
264	;; ;call AuxIO_TeletypeHexDWord
265	;; ;call AuxIO_TeletypeNL
266	;; pop dx
267
268	;; xor dh,dh
269	;; and dl,01111111b
270	;; shl dx,1
271	;; shl dx,1
272	;; mov bx, offset [TrueSecs]
273	;; add bx,dx
274	;; mov ax, word ptr[bx]
275
276	;call AuxIO_TeletypeHexWord
277	;call AuxIO_TeletypeNL
278	;; mov al,[ExtendedAbsPosSet] ; if true -> 1st sector of extpart (EBR), not logpart(BPB)
279	;call AuxIO_TeletypeHexByte
280	;call AuxIO_TeletypeNL
281	;mov si,offset PartitionSector
282	;call AuxIO_DumpSector
283	;; popa
284
285	; LBA
286	;mov si,offset before_lvm_adjust
287	;call AuxIO_Print
288
289	;xchg dx,bx
290	;call AuxIO_TeletypeHexDWord
291	;call AuxIO_TeletypeNL
292	;xchg bx,dx
293	;; popa
294
295
296	;;bliep:
297
298	;or bx,ax
299	;; test byte ptr [ExtendedAbsPosSet],1
300	;; jz pri
301
302
303	;; push dx
304	;; push bx
305
306	;; xor dh,dh
307	;; and dl,01111111b ; Strip high bit from disk
308	;; shl dx,1 ; Convert to index
309	;; shl dx,1 ; into TrueSecs table
310	;; mov bx,offset [TrueSecs] ; Base of table
311	;; add bx,dx ; Point to entry for disk
312	;; mov dx,[bx] ; Get TrueSecs (LVM)
313	;; dec dx
314	;; add ax,dx
315
316	;; pop bx
317	;; pop dx
318	;; adc bx,0
319
320
321	;; jmp done
322
323
324
325	;; pri:
326
327
328	;; push ax
329	;; push cx
330	;; xor ch, ch ; Zero out upper-byte
331
332	;; push dx
333	;; xor dh,dh
334	;; and dl,01111111b
335	;; shl dx,1
336	;; shl dx,1
337
338	;; push bx
339	;; mov bx,offset [TrueSecs]
340	;; add bx,dx
341	;; mov ax,[bx]
342	;mov [ts2],ax
343	;; pop bx
344	;; pop dx
345
346
347
348	;~ mov al, 63
349	;~ call VideoIO_PrintByteDynamicNumber
350	;~ self: jmp self
351
352
353
354	; DEZE WERKT SOMS NIET GOED
355	; ROMMELT MET CYLINDERS
356	; ALLEEN TOEPASSEN ALS INT13X NIET ACTIEF !
357
358	;; and cl, al ; Isolate lower bits, because upper
359	;; mov ah, 0
360	;; mov si, ax ; ones may be used for cylinder
361	;; sub si, cx
362
363	;; pop cx
364	;; pop ax
365
366	;; or cl, al ; Set sector to last sector
367	;; add ax, si ; Adjust lower LBA
368	;; adc bx, 0 ; Adjust LBA Sector (BX:AX)
369
370
371
372	;~ push ax
373	;~ call AuxIO_TeletypeHexWord
374	;~ call AuxIO_TeletypeNL
375	;~ mov ax,[ts]
376	;~ call AuxIO_TeletypeHexWord
377	;~ call AuxIO_TeletypeNL
378	;~ mov ax,[ts2]
379	;~ call AuxIO_TeletypeHexWord
380	;~ call AuxIO_TeletypeNL
381	;~ pop ax
382
383	;~ and ax,[ts]
384
385	;; jmp done
386
387
388
389	;; done:
390
391	;pusha
392	;mov si,offset after_lvm_adjust
393	;~ call AuxIO_Print
394	; LBA
395	;xchg dx,bx
396	;~ call AuxIO_TeletypeHexDWord
397	;~ call AuxIO_TeletypeNL
398	;xchg bx,dx
399	;popa
400
401	;~ pusha
402	;~ call AuxIO_TeletypeNL
403	;~
404	;~ ; CYL
405	;~ mov al,ch
406	;~ call AuxIO_TeletypeHexByte
407	;~ call AuxIO_TeletypeNL
408	;~
409	;~ ; HEAD
410	;~ mov al,dh
411	;~ call AuxIO_TeletypeHexByte
412	;~ call AuxIO_TeletypeNL
413	;~
414	;~ ; SEC
415	;~ mov al,cl
416	;~ call AuxIO_TeletypeHexByte
417	;~ call AuxIO_TeletypeNL
418	;~
419	;~ ; DRIVE
420	;~ mov al,dl
421	;~ call AuxIO_TeletypeHexByte
422	;~ call AuxIO_TeletypeNL
423	;~ popa
424
425	;; ret
426	DriveIO_LVMAdjustToInfoSector EndP
427
428
429
430
431
432
433	; #########################################################################
434	; Routine: Loads partition to ExecBase and checks for validity
435	; #########################################################################
436	; Calling : bx:ax - Absolute sector
437	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
438	; Returns : Carry Set if invalid partition encountered
439	; Preserve: all registers
440	; #########################################################################
441	DriveIO_LoadPartition Proc Near Uses si
442	mov wptr cs:[CurPartition_Location+0], ax
443	mov wptr cs:[CurPartition_Location+2], bx
444	mov wptr cs:[CurPartition_Location+4], dx
445	mov wptr cs:[CurPartition_Location+6], cx ; Saves the location
446	mov si, offset PartitionSector ; DS:SI - ExecBase
447	call DriveIO_LoadSector
448	clc
449	cmp wptr [si+LocBR_Magic], 0AA55h
450	je DIOLP_Success
451	; We check, if we are scanning partitions. In that case, if CHS is not 0/0/1
452	; we will display a "bad partition table" message and halt the system.
453	cmp cx, 0001h
454	jne DIOLP_Failed
455	or dh, dh
456	jnz DIOLP_Failed
457	stc ; Set carry, so no partition table
458	DIOLP_Success:
459
460	IFDEF AUX_DEBUG
461	; show current partition location
462	;~ pushf
463	;~ pusha
464	;~ call AuxIO_TeletypeNL
465	;~ mov si,offset db_curpartloc
466	;~ call AuxIO_Print
467	;~ mov dx,word ptr [CurPartition_Location+02]
468	;~ mov ax,word ptr [CurPartition_Location+00]
469	;~ call AuxIO_TeletypeHexDWord
470	;~ call AuxIO_TeletypeNL
471	;~ mov si,offset PartitionSector
472	;~ call AuxIO_DumpSector
473	;~ call AuxIO_TeletypeNL
474	;~ popa
475	;~ popf
476	ENDIF
477
478	ret
479	DIOLP_Failed:
480	jmp DriveIO_GotLoadError
481	DriveIO_LoadPartition EndP
482
483	; #########################################################################
484	; Routine: Writes a partition from ExecBase to its original sector
485	; #########################################################################
486	; Calling : none
487	; Returns : none
488	; Preserve: all registers
489	; #########################################################################
490	DriveIO_SavePartition Proc Near Uses ax bx cx dx si
491	mov ax, wptr cs:[CurPartition_Location+0]
492	mov bx, wptr cs:[CurPartition_Location+2]
493	mov dx, wptr cs:[CurPartition_Location+4]
494	mov cx, wptr cs:[CurPartition_Location+6] ; Gets prev. saved location
495	mov si, offset PartitionSector ; DS:SI - ExecBase
496	cmp wptr [si+LocBR_Magic], 0AA55h ; Checks for signature, if not found
497	jne DIOSP_SevereError ; we assume a really bad error
498	call DriveIO_SaveSector
499	DIOSP_SevereError:
500	ret
501	DriveIO_SavePartition EndP
502
503	; Keeps DS:SI for caller
504	DriveIO_LoadTmpSector Proc Near
505	mov si, offset TmpSector
506	call DriveIO_LoadSector
507	ret
508	DriveIO_LoadTmpSector EndP
509
510	; Keeps DS:SI for caller
511	DriveIO_SaveTmpSector Proc Near
512	mov si, offset TmpSector
513	call DriveIO_SaveSector
514	ret
515	DriveIO_SaveTmpSector EndP
516
517
518
519	; Keeps DS:SI for caller, sets carry if valid LVM sector encountered
520	DriveIO_LoadLVMSector Proc Near Uses ax bx cx dx
521	test byte ptr [CFG_IgnoreLVM], 1 ; We are supposed to ignore LVM, so
522	jnz DIOLLVMS_NoLVMSector ; don't load but declare as bad!
523	mov ax, wptr cs:[CurPartition_Location+0]
524	mov bx, wptr cs:[CurPartition_Location+2]
525	mov dx, wptr cs:[CurPartition_Location+4]
526	mov cx, wptr cs:[CurPartition_Location+6] ; Gets cur. partition location
527
528	call DriveIO_LVMAdjustToInfoSector
529
530	mov si, offset LVMSector
531	call DriveIO_LoadSector
532
533	IFDEF AUX_DEBUG
534	; show current partition location
535	;~ pushf
536	;~ pusha
537	;~ call AuxIO_TeletypeNL
538	;~ mov si,offset db_curlvmsec
539	;~ call AuxIO_Print
540	;~ mov dx,bx
541	;~ call AuxIO_TeletypeHexDWord
542	;~ call AuxIO_TeletypeNL
543	;~ mov si,offset LVMSector
544	;~ call AuxIO_DumpSector
545	;~ call AuxIO_TeletypeNL
546	;~ popa
547	;~ popf
548	ENDIF
549
550	call LVM_CheckSectorSignature
551	jnc DIOLLVMS_NoLVMSector
552	call LVM_CheckSectorCRC
553	jnc DIOLLVMS_NoLVMSector
554	ret
555	; This here is called, if an invalid (or no) LVM information sector is found
556	; It will truncate the first byte of the sector, so all other routines
557	; will notice it easily by just comparing the first byte.
558	DIOLLVMS_NoLVMSector:
559	mov bptr [si+LocLVM_SignatureStart], 0
560	ret
561	DriveIO_LoadLVMSector EndP
562
563
564
565	; Keeps DS:SI for caller, saves at anytime w/o checks (!)
566	DriveIO_SaveLVMSector Proc Near Uses ax bx cx dx
567	test byte ptr [CFG_IgnoreLVM], 1 ; We are supposed to ignore LVM, so
568	jnz DIOSLVMS_SevereError ; don't save at anytime (security!)
569	mov ax, wptr cs:[CurPartition_Location+0]
570	mov bx, wptr cs:[CurPartition_Location+2]
571	mov dx, wptr cs:[CurPartition_Location+4]
572	mov cx, wptr cs:[CurPartition_Location+6] ; Gets cur. partition location
573	call LVM_CheckSectorSignature
574	jnc DIOSLVMS_SevereError ; LVM Signature must be there
575
576	IFDEF AUX_DEBUG
577	;~ dioatlvm db 'DriveIO_LVMAdjustToInfoSector',10,0
578	;~ pushf
579	;~ pusha
580	;~ mov si,offset dioatlvm
581	;~ call AuxIO_Print
582	;~ popa
583	;~ popf
584	call DEBUG_DumpRegisters
585	call DEBUG_DumpCHS
586	ENDIF
587
588	call DriveIO_LVMAdjustToInfoSector
589
590	IFDEF AUX_DEBUG
591	call DEBUG_DumpRegisters
592	call DEBUG_DumpCHS
593	ENDIF
594
595	mov si, offset LVMSector
596	call DriveIO_SaveSector
597	DIOSLVMS_SevereError:
598	ret
599	DriveIO_SaveLVMSector EndP
600
601	; Rousseau: Move this to BSS and merge with int13xbuf there.
602
603	; Memory-Block that holds information for LBA-access via INT 13h
604	DriveIO_DAP db 10h ; Size of paket
605	db 0 ; Reserved
606	DriveIO_DAP_NumBlocks dw 0 ; Number of blocks
607	DriveIO_DAP_Transfer dd 0 ; Transfer Adress
608	DriveIO_DAP_Absolute dd 0 ; Absolute Sector
609	dd 0 ; Second Part of QWORD
610
611	; Special error message instead of "LOAD ERROR" during partition scanning,
612	; so users will notice that something is bad with their partition table(s)
613	DriveIO_GotLoadError Proc Near
614	test byte ptr cs:[CurIO_Scanning], 1 ; Must be CS:, cause DS!=CS maybe here
615	jnz InScanMode
616	jmp MBR_LoadError
617	InScanMode:
618	mov si, offset TXT_BrokenPartitionTable
619	push cs
620	pop ds
621	call MBR_Teletype
622	mov si, offset BrokenHDD
623	sub dl, 50h ; 80h -> '0'
624	cmp dl, 39h
625	jbe DIOGLE_BelowA
626	add dl, 7 ; 3Ah -> 'A'
627	DIOGLE_BelowA:
628	mov bptr [si+5], dl
629	call MBR_Teletype
630
631	; JWasm: cannot jump to local label in other procedure.
632	; Changed to halt here.
633	;jmp MBRLE_Halt
634	DriveIO_GotLoadError_halt:
635	jmp DriveIO_GotLoadError_halt
636	DriveIO_GotLoadError EndP
637
638	; #########################################################################
639	; Routine: Loads a specified sector to DS:DI
640	; #########################################################################
641	; Calling : bx:ax - Absolute sector
642	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
643	; ds:si - Destination-Adress
644	; Returns : none
645	; Preserve: all registers
646	; #########################################################################
647	DriveIO_LoadSector Proc Near Uses ax bx cx dx ds si es di
648	; Is the drive not a harddrive?
649	cmp dl, 80h
650	jb DIOLS_UseNormal
651
652	test byte ptr cs:[CurIO_UseExtension], 1
653	jz DIOLS_UseNormal
654	; Are we forced do use LBA via Setting?
655	jnz DIOLS_UseExtension
656
657	; Upper 8 bits of LBA-address set?
658	; Then use LBA (maximum boundary is 16320x16x63 = FB0400h)
659	or bh, bh
660	jnz DIOLS_UseExtension
661	; Compare Switch-Table value to bit 16-23 of LBA-address
662	mov di, dx
663	and di, 007Fh
664	cmp bptr cs:[LBASwitchTable+di], bl
665	jbe DIOLS_UseExtension
666	DIOLS_UseNormal:
667	mov di, 3
668	DIOLS_ErrorLoop:
669	push ds
670	pop es
671	mov bx, si ; ES:BX - Destination
672	mov ax, 0201h ; Function 2 - Load Sector
673	int 13h
674	jnc DIOLS_Success
675	dec di
676	jnz DIOLS_ErrorLoop
677	; Sector load failed...
678	jmp DriveIO_GotLoadError
679
680	DIOLS_UseExtension:
681	push cx
682	mov cs:[DriveIO_DAP_NumBlocks], 1 ; Copy ONE sector
683	mov wptr cs:[DriveIO_DAP_Transfer+0], si
684	mov cx, ds
685	mov wptr cs:[DriveIO_DAP_Transfer+2], cx ; Fill out Transfer Adress
686	mov wptr cs:[DriveIO_DAP_Absolute+0], ax
687	mov wptr cs:[DriveIO_DAP_Absolute+2], bx ; Fill out Absolute Sector
688	push cs
689	pop ds
690	mov si, offset DriveIO_DAP
691	mov ah, 42h ; Extended Read
692	int 13h
693	pop cx
694	jnc DIOLS_Success
695	; Sector load failed...
696	jmp DriveIO_GotLoadError
697
698	DIOLS_Success:
699	ret
700	DriveIO_LoadSector EndP
701
702
703
704	;
705	; ############################################################
706	; # Load a specified sector from a disk using LBA addressing #
707	; ############################################################
708	;
709	; In
710	; --
711	; DL = Physical Disk
712	; BX:CX = LBA sector
713	; DI:SI = Target buffer
714	;
715	; Out
716	; ---
717	; AX = Error code
718	;
719	DriveIO_LoadSectorLBA Proc Near Uses bx cx dx si di ds es
720	; Get one sector
721	mov cs:[DriveIO_DAP_NumBlocks], 1
722
723	; Setup buffer address
724	mov wptr cs:[DriveIO_DAP_Transfer+0], si
725	mov wptr cs:[DriveIO_DAP_Transfer+2], di
726
727	; Setup LBA address of requested sector
728	mov wptr cs:[DriveIO_DAP_Absolute+0], cx
729	mov wptr cs:[DriveIO_DAP_Absolute+2], bx
730	mov wptr cs:[DriveIO_DAP_Absolute+4], 0
731	mov wptr cs:[DriveIO_DAP_Absolute+6], 0
732
733	; Address of packet
734	mov si, offset DriveIO_DAP
735
736	; Do the extended read
737	mov ah, 42h
738	int 13h
739
740	; Looking good so far
741	jnc DriveIO_LoadSectorLBA_succes1
742
743	; AH should not be zero, if it is then set to undefined and set carry
744	test ah,ah
745	jnz DriveIO_LoadSectorLBA_error1
746	mov ah, 0bbh ; Undefined error
747	DriveIO_LoadSectorLBA_error1:
748	stc
749	jmp DriveIO_LoadSectorLBA_exit
750
751	; AL should be zero, if not then set to undefined and set carry
752	DriveIO_LoadSectorLBA_succes1:
753	test ah,ah
754	jz DriveIO_LoadSectorLBA_exit
755	stc
756	jmp DriveIO_LoadSectorLBA_exit
757
758	; Return to caller
759	DriveIO_LoadSectorLBA_exit:
760	ret
761	DriveIO_LoadSectorLBA EndP
762
763
764
765	;
766	; ############################################################
767	; # Check for a valid MBR-sector to be written to disk #
768	; ############################################################
769	;
770	; In
771	; --
772	; DL = Physical Disk
773	; BX:CX = LBA sector
774	; DI:SI = Source buffer
775	;
776	; Out
777	; ---
778	; CY = 1 if invalid MBR in source buffer, 0 if valid
779	;
780	; This routine is called when DriveIO_SaveSector attempts to write to the MBR.
781	; It checks if the sector to be written has some sensible values in certain
782	; places. In fact, if the sector is written to the boot-disk, the AiR-BOOT
783	; signature should be present and the partition table should be the same
784	; as the one at the start of the AiR-BOOT code in memory, except maybe for the
785	; active flags.
786	; For other disks, only the active flags are checked to be 00h or 80h and
787	; the AA55h MBR signature.
788	;
789	DriveIO_ProtectMBR Proc Near
790	pusha ; Push all registers
791	push es ; Push ES because we need it for string instructions
792	push cs ; Make ES point...
793	pop es ; to CS
794
795	; Save the pointer to the sector to write in BX
796	mov bx,si
797
798	;
799	; If the sector to be written is not the boot-disk, then skip
800	; checking the AiR-BOOT MBR.
801	;
802	cmp dl,80h
803	ja DriveIO_ProtectMBR_is_not_bootdisk
804
805	;
806	; The boot-disk is accessed so the sector to be written must be
807	; the AiR-BOOT MBR. This is the same as the first 512 bytes
808	; relocated to 8000:0000 and this the start of the AB-code.
809	;
810	mov si,bx ; Get pointer to sector to write
811	xor di,di ; Point DI to start of AB-code (MBR)
812	mov cx, offset [MBR_PartTable] ; Bytes upto P-table must be same
813	cld ; Compare upwards
814	repe cmpsb ; Compare upto P-table
815
816	; If not the same this is not the an AiR-BOOT boot-disk MBR !
817	jne DriveIO_ProtectMBR_not_valid_MBR ; SEVERE ERROR !
818
819	; Continue with signature check
820	jmp DriveIO_ProtectMBR_check_signature
821
822
823	;
824	; The disk is not the boot-disk so we don't know what kind of MBR is on it.
825	; Some sanity checks should be here.
826	;
827	DriveIO_ProtectMBR_is_not_bootdisk:
828
829	;
830	; sanity checks...
831	;
832
833	; Continue with signature check
834	jmp DriveIO_ProtectMBR_check_signature
835
836
837	DriveIO_ProtectMBR_check_signature:
838	; See if the sector to write contains a valid signature
839	mov si,bx ; Get pointer to sector to write
840	mov di, offset [MBR_Sig] ; Offset to MBR signature
841	add si,di ; Make SI point to it in sec to write
842	lodsw ; Load it
843	cmp ax,0aa55h ; See if it is valid
844
845	; If no signature this cannot be a valid MBR !
846	jne DriveIO_ProtectMBR_not_valid_MBR ; SEVERE ERROR !
847
848
849	;
850	; The sector to be written seems to be valid.
851	; Set CY=0 to indicate a valid MBR.
852	;
853	DriveIO_ProtectMBR_is_valid_MBR:
854	clc
855	jmp DriveIO_ProtectMBR_end
856
857	;
858	; Something is terribly wrong; a non-MBR sector seems about to be written.
859	; Set CY=1 and let the calling code handle this situation.
860	;
861	DriveIO_ProtectMBR_not_valid_MBR:
862	stc
863	jmp DriveIO_ProtectMBR_end
864
865	;
866	; Return to the caller with no registers modyfied except FLAGS.
867	;
868	DriveIO_ProtectMBR_end:
869	pop es
870	popa
871	ret
872	DriveIO_ProtectMBR Endp
873
874
875
876	; #########################################################################
877	; Routine: Checks if the MBR is addressed by either CHS or LBA
878	; #########################################################################
879	; Calling : bx:ax - Absolute sector
880	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
881	; Returns : ZF=1 if MBR is addressed, else ZF=0
882	; Preserve: all registers
883	; #########################################################################
884	DriveIO_MBR_Addressed Proc
885	push ax
886	push bx
887
888	or bx,ax ; Results in 0 in BX if MBR is addressed by LBA
889	jz DriveIO_MBR_Addressed_done
890
891	mov ax,cx ; Results in 1 in AX if CYL 0, SEC 1 is addressed
892	add al,dh ; Results in 1 in AX if HEAD 0 is addressed
893	dec ax ; Results in 0 in AX if MBR is addressed by CHS
894
895	DriveIO_MBR_Addressed_done:
896	pop bx
897	pop ax
898	ret
899	DriveIO_MBR_Addressed EndP
900
901
902
903
904	; #########################################################################
905	; Routine: Writes DS:SI to a specified sector
906	; #########################################################################
907	; Calling : bx:ax - Absolute sector
908	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
909	; ds:si - Source-Adress
910	; Returns : none
911	; Preserve: all registers
912	; #########################################################################
913	DriveIO_SaveSector Proc Near Uses ax bx cx dx ds si es di
914
915
916	;!
917	;! DEBUG_BLOCK
918	;! Force write to LBA0 to test interception routine.
919	;! Do NOT enable unless you are debugging, will overwrite MBR !
920	;!
921	;~ __DIO_FORCE_LBA0_WRITE__ EQU
922	IFDEF AUX_DEBUG
923	IFDEF __DIO_FORCE_LBA0_WRITE__
924	xor ax,ax
925	xor bx,bx
926	xor cx,cx
927	inc cx
928	xor dh,dh
929	ENDIF
930	ENDIF
931
932
933	;!
934	;! DEBUG_BLOCK
935	;! Check what is being written to disk.
936	;! Uncomment below to activate.
937	;!
938	__DIO_SS_DMP__ EQU
939	IFDEF AUX_DEBUG
940	IFDEF __DIO_SS_DMP__
941	pusha
942	push si
943	mov si,offset dioss
944	call AuxIO_Print
945	pop si
946	call DEBUG_DumpRegisters
947	call AuxIO_DumpSector
948	call AuxIO_TeletypeNL
949	popa
950	ENDIF
951	ENDIF
952
953	;
954	; Check if the MBR is the destination for the write.
955	; ZF=1 if so.
956	;
957	call DriveIO_MBR_Addressed
958	jnz DriveIO_SaveSector_continue_write
959
960
961	; MBR is addressed, check the sector that is requested to be written.
962	; For the bootdisk it should contain the AiR-BOOT signature, valid
963	; partition-table entries and the AA55h signature.
964	; If not, something is terribly wrong in some piece of the AB code.
965	; For any other disk (80h+) at least a valid partition table should
966	; be present together with the AA55h signature.
967	call DriveIO_ProtectMBR
968	jnc DriveIO_SaveSector_continue_write
969
970
971	;
972	; WE HAVE A SEVERE ERROR CONDITION !
973	; SOME AB CODE TRIES TO WRITE A NON-MBR TO THE DISK !
974	; ASK THE USER TO REPORT THIS !
975	; HALT THE SYSTEM !
976	;
977
978	; Show error-box
979	mov cx, 0C04h
980	mov si, offset NonMBRwrite
981	call SETUP_ShowErrorBox
982	mov cx, 0C04h
983	mov si, offset NonMBRwrite_rep
984	call SETUP_ShowErrorBox
985
986
987	IFDEF AUX_DEBUG
988	pusha
989	mov si, offset NonMBRwrite
990	call AuxIO_TeletypeNL
991	call AuxIO_Print
992	call AuxIO_TeletypeNL
993	popa
994	ENDIF
995
996	; Show popup and halt the system.
997	jmp HaltSystem
998
999
1000
1001	;
1002	; Continue the write if not MBR sector or MBR to write is validated.
1003	;
1004	DriveIO_SaveSector_continue_write:
1005	test byte ptr cs:[CurIO_UseExtension], 1
1006	jz DIOSS_UseNormal
1007	; Are we forced do use LBA via Setting?
1008	; Always use INT13X on v1.0.8.
1009	;~ test byte ptr cs:[CFG_ForceLBAUsage], 1
1010	;~ jnz DIOSS_UseExtension
1011	jmp DIOSS_UseExtension
1012	; Is the drive not a harddrive?
1013	cmp dl, 80h
1014	jb DIOSS_UseNormal
1015	; Upper 8 bits of LBA-address set? -> Use LBA (maximum boundary is FB0400h)
1016	or bh, bh
1017	jnz DIOSS_UseExtension
1018	; Compare Switch-Table value to bit 16-23 of LBA-address
1019	mov di, dx
1020	and di, 007Fh
1021	cmp bptr cs:[LBASwitchTable+di], bl
1022	jbe DIOSS_UseExtension
1023	DIOSS_UseNormal:
1024	mov di, 3
1025	DIOSS_ErrorLoop:
1026	push ds
1027	pop es
1028	mov bx, si ; ES:BX - Destination
1029	mov ax, 0301h ; Function 3 - Write Sector
1030	int 13h
1031	jnc DIOSS_Success
1032	dec di
1033	jnz DIOSS_ErrorLoop
1034	call MBR_SaveError
1035
1036	DIOSS_UseExtension:
1037	push cx
1038	mov cs:[DriveIO_DAP_NumBlocks], 1 ; Copy ONE sector
1039	mov wptr cs:[DriveIO_DAP_Transfer+0], si
1040	mov cx, ds
1041	mov wptr cs:[DriveIO_DAP_Transfer+2], cx ; Fill out Transfer Adress
1042	mov wptr cs:[DriveIO_DAP_Absolute+0], ax
1043	mov wptr cs:[DriveIO_DAP_Absolute+2], bx ; Fill out Absolute Sector
1044	push cs
1045	pop ds
1046	mov si, offset DriveIO_DAP
1047	mov ax, 4300h ; Extended Write (No Verify)
1048	int 13h
1049	pop cx
1050	jnc DIOSS_Success
1051	call MBR_SaveError
1052
1053	DIOSS_Success:
1054	ret
1055	DriveIO_SaveSector EndP
1056
1057
1058	; See if a LVM-sector is valid.
1059	; In : si, pointer to sector
1060	; Out : CY if valid LVM sector, NC if not
1061	DriveIO_LVMSectorValid Proc Near
1062	pusha
1063
1064	call LVM_CheckSectorSignature
1065	; NC if no signature found
1066	jnc DriveIO_LVMSectorValid_End
1067
1068	call LVM_CheckSectorCRC
1069	; Force valid !!!
1070	stc
1071
1072	DriveIO_LVMSectorValid_End:
1073	popa
1074	ret
1075	DriveIO_LVMSectorValid EndP
1076
1077	; ------------------------------------------------------
1078	; Rousseau: # Load the master LVM-sector if one exists #
1079	; ------------------------------------------------------
1080	; Load the master LVM-sector to get the number of sectors per track as
1081	; eCS views the drive. If no master LVM-sector is found it is assumed eCS
1082	; is not installed. The master LVM-sector can be located at three different
1083	; places depending on drive size and partitioning scheme and driver used.
1084	; When DANIS506.ADD is used, the eCS extended geometry will be 255/127 for
1085	; drives >502GiB but <1TiB. Then the location will be sector 127 which
1086	; is LBA 126 (7Eh).
1087	; IBM1S506.ADD will always use 255/255 for the extended eCS geometry.
1088	; DANIS506.ADD will use 255/255 for drives >1TiB.
1089	; Then the location of the master LVM-sector will be 255 which is LBA 254 (FEh).
1090	; When eCS is installed on a huge drive that alread had a system on it, eCS
1091	; will be confined to the lower 502GiB of the drive.
1092	; In this case the normal geometry from Int13X will be used.
1093	; This is also the case when no valid master LVM-sector can be found.
1094	;
1095	; Return CF when valid master LVM sector found, NC if not.
1096	; Loads sector at [LVMSector] !
1097	DriveIO_LoadMasterLVMSector Proc Near
1098	pusha
1099
1100	;~ mov si,offset db_lmlvm
1101	;~ call AuxIO_Print
1102
1103	;~ ; Physical disk
1104	;~ mov al,'<'
1105	;~ call VideoIO_PrintSingleChar
1106	;~ mov al,dl
1107	;~ call VideoIO_PrintHexByte
1108	;~ mov al,'>'
1109	;~ call VideoIO_PrintSingleChar
1110	;~
1111	;~ call AuxIO_TeletypeHexByte
1112	;~ call AuxIO_TeletypeNL
1113
1114
1115	; Loop over the sector-translation table,
1116	; process the first three values from high (255) to low.
1117	; (bios spt, most likely 63)
1118	mov cx,3
1119	DriveIO_LoadMasterLVMSector_NextTry:
1120	; Number of sectors to read
1121	mov [DriveIO_DAP_NumBlocks],1
1122
1123	; Setup destination address
1124	mov si, offset [LVMSector]
1125	mov word ptr [DriveIO_DAP_Transfer+0],si
1126	mov ax, ds
1127	mov word ptr [DriveIO_DAP_Transfer+2],ax
1128
1129	; Get the sector-number of the next possible LVM sector (255,127,63)
1130	; using the translation table and the counter as the index
1131	mov bx,offset secs_per_track_table
1132	mov ax,cx
1133	dec ax
1134	xlatb
1135	dec al
1136
1137	;
1138	; AX now contains the LBA address of the sector
1139	; that could be an LVM sector.
1140	; This is all in track0 so the address will not exceed 64kiB sectors.
1141	;
1142
1143	;~ push ax
1144	;~ push ax
1145	;~ mov al,'$'
1146	;~ call VideoIO_PrintSingleChar
1147	;~ pop ax
1148	;~ call VideoIO_PrintHexByte
1149	;~ mov al,'$'
1150	;~ call VideoIO_PrintSingleChar
1151	;~ pop ax
1152
1153	IFDEF AUX_DEBUG
1154	; Dump the value
1155	;~ call AuxIO_TeletypeHexByte
1156	;~ call AuxIO_TeletypeNL
1157	ENDIF
1158
1159	; Setup the requested LBA sector number
1160	mov word ptr [DriveIO_DAP_Absolute+0],ax ; LBA low NORMAL I/O GEBRUIKEN !
1161	mov word ptr [DriveIO_DAP_Absolute+2],00h ; LBA high
1162	mov si, offset DriveIO_DAP ; address request packet
1163	mov ah, 42h
1164	int 13h ; do the i/o
1165	cmc ; Complement carry so we can exit imm. on error
1166	jnc DriveIO_LoadMasterLVMSector_End ; oops, return with NC
1167
1168
1169	mov si,offset [LVMSector]
1170
1171	; See if this is a valid LVM-sector
1172	; CY=1 if valid
1173	call DriveIO_LVMSectorValid
1174
1175	; pushf
1176	; mov ah,0
1177	; rcl ah,1
1178	; mov al,'\|'
1179	; call VideoIO_PrintSingleChar
1180	; mov al,ah
1181	; call VideoIO_PrintHexByte
1182	; mov al,'\|'
1183	; call VideoIO_PrintSingleChar
1184	; popf
1185
1186
1187	; Yep, we found the master LVM-sector
1188	jc DriveIO_LoadMasterLVMSector_Found
1189	; Try next location
1190	loop DriveIO_LoadMasterLVMSector_NextTry
1191
1192	; No master LVM-sector found, set CF=false
1193	clc
1194
1195	DriveIO_LoadMasterLVMSector_Found:
1196	; Store the address for later use.
1197	mov ax, word ptr [DriveIO_DAP_Absolute]
1198	mov word ptr [MasterLVMLBA], ax
1199
1200	DriveIO_LoadMasterLVMSector_End:
1201	popa
1202	ret
1203	DriveIO_LoadMasterLVMSector Endp
1204
1205
1206
1207
1208	; ---------------------------------------------------
1209	; Rousseau ## Large drives, (eCS) geometry and LBA ##
1210	; ---------------------------------------------------
1211	; A sector size of 512 bytes is assumed in the below calculations.
1212	; Note that this scheme changes when the sector size will be 4096 or larger,
1213	; like with modern drives that do not translate to 512 bytes per sector anymore.
1214	; These drives will have a capacity above the 2TiB LBA32 boundary.
1215	; For now, we assume drives <=2TiB with a sector size of 512 bytes.
1216
1217	; There are a few boundaries that are of importance.
1218	; Note that these are disk-boundaries and not partition boundaries.
1219	; Even with a small partition, like <502GiB, OS/2 will use extended geometry on
1220	; an empty huge disk.
1221	; These boundaries are (from high to low):
1222
1223	; (code 5)
1224	; 2^32 = 4294967296 = 100000000 sectors = 2048 GiB
1225	; This is the LBA32 2TiB boundary.
1226	; Everything above it must be addressed using LBA48.
1227	; OS/2 can currently not address this space above.
1228
1229	; (code4)
1230	; 65536255255 = 4261478400 = FE010000 sectors ~ 2032 GiB
1231	; This is the max OS/2 boundary using 255/255 extended geometry.
1232	; OS/2 can currently not address this space above.
1233
1234	; (code 3)
1235	; 2^31 = 2147483648 = 80000000 sectors = 1024 GiB
1236	; This is the LBA32 1TiB boundary.
1237	; OS/2 can address this space and will use 255/255 extended geometry.
1238
1239	; (code 2)
1240	; 65536255127 = 2122383360 = 7E810000 sectors ~ 1012 GiB
1241	; This is the DANI 1TiB boundary.
1242	; OS/2 can address this space and will use 255/255 extended geometry.
1243	; Below this DANI will use 255/127 extended geometry.
1244	; This matters on where the LVM-sectors are located !
1245
1246	; (code 1)
1247	; 6553625563 = 1052835840 = 3EC10000 sectors ~ 502 GiB
1248	; This is the current OS/2 limit using this geometry because OS/2 can
1249	; currently not address more than 65536 cylinders.
1250	; DANI will address space above with 255/127 extended geometry up until
1251	; the DANI 1TiB boundary (code 2)
1252
1253	; (code 0)
1254	; Everything below 6553625563 will be addressed using standard geometry.
1255
1256
1257	;
1258	; This function will return the following values:
1259	;
1260
1261	; 5 = This drive is above the 2^32 LBA32 (2TB) boundary and has more
1262	; than 4294967296 sectors.
1263	; LBA48 addressing is needed to access the complete capacity of the drive.
1264	; OS/2 is currently unable to do so.
1265
1266	; 4 = This drive is above the 65536255255 (4261478400) boundary but below 2^32.
1267	; This is an OS/2 boundary and OS/2 is not able to access the drive above
1268	; this boundary.
1269
1270	; 3 = This drive is above the 2^31 (1TB) boundary and has more than
1271	; 2147483648 sectors.
1272	; OS/2 is able to access the drive using it's extended geometry.
1273	; Both DANIS506 and IBM1S506 will use the 255/255 scheme.
1274
1275	; 2 = This drive is above the 65536255127 (2122383360) boundary but below 2^31.
1276	; OS/2 is able to access the drive using it's extended geometry.
1277	; Both DANIS506 and IBM1S506 will use the 255/255 scheme.
1278
1279	; 1 = This drive is above the 6553625563 (1052835840) boundary but
1280	; below 65536255127.
1281	; OS/2 is able to access the drive using it's extended geometry.
1282	; Note that DANIS506 will use 255/127 and IBM1S506 will use 255/255 geometry !
1283	; Using DANI or IBM influences the location of the LVM info-sectors !
1284
1285	; 0 = This drive is below the 6553625563 (1052835840) boundary.
1286	; OS/2 is able to access this drive using the standard 255/63 geometry.
1287
1288	; So, any return value >0 means OS/2 extended geometry will be used.
1289	; Value 1 will use 255/127 with DANIS506 but 255/255 with IBM1S506.
1290	; Values 2 and 3 will use 255/255 on both drivers.
1291	; You can or with 0x01 and check for 3 in this case.
1292	; Any value above 3 will be a drive who's capacity cannot be fully used by OS/2
1293	; The upper limit of 65536255255 will be in effect here.
1294
1295	; Note this function currently handles the boot-drive only !
1296	; It should be extended and use dl for the drive-number as a parameter.
1297	; Because we use this function to get this info in a number of places,
1298	; all regs and flags except AX are saved and restored.
1299
1300	; DL contains BIOS disk-number; 80h for first, 81h for second, etc.
1301	DriveIO_GatherDiskInfo Proc Near
1302	pushf
1303	push bx
1304	push cx
1305	push dx
1306	push si
1307	push di
1308	push es
1309
1310	; Set ES to CS for buffer clearing
1311	push cs
1312	pop es
1313
1314	; Clear the buffer
1315	; Also setup the buffer size.
1316	; Old Phoenix BIOSses require word (flags) at 02 to be zero,
1317	; so we clear the whole buffer to be sure.
1318	mov cx, i13xbuf_size ; Dynamically calculated by assembler.
1319	mov di, offset i13xbuf ; Points to size field.
1320	mov [di],cx ; Setup buffer-size.
1321	inc di
1322	inc di ; Now pointing at actual buffer.
1323	xor ah,ah ; Fill value.
1324	cld ; Direction up.
1325	rep stosb ; Clear buffer.
1326
1327	; Get the drive parameters
1328	mov ah, 48h ; Get Drive Parameters (extended version)
1329	;mov dl, 80h ; Drive number
1330	mov si, offset i13xbuf ; Buffer for result-info
1331	push dx
1332	int 13h ; Call the BIOS-function
1333	pop dx
1334
1335	; Do some error-checking
1336	or ah,ah ; AH is zero if no error (ZF=1 if no error)
1337	mov ax,0 ; Setup code for non-huge drive (does not influence ZF)
1338	jz DriveIO_GatherDiskInfo_ok ; Return if error (AL<>0 thus ZF=0) but CY not set, assuming non-huge drive
1339	jnc DriveIO_GatherDiskInfo_ok ; Return if error (CY=1), assuming non-huge drive
1340	jmp DriveIO_GatherDiskInfo_ret
1341
1342
1343	DriveIO_GatherDiskInfo_ok:
1344
1345	;
1346	; Store the drive geometry
1347	;
1348
1349	mov si, offset i13xbuf
1350
1351	xor dh,dh
1352	and dl,01111111b
1353	shl dx,1
1354	shl dx,1
1355
1356	; Store number of cylinders on disk
1357	mov bx, offset BIOS_Cyls
1358	add bx,dx
1359	mov ax,[si+04h]
1360
1361	mov word ptr [bx+00],ax
1362	mov ax,[si+06]
1363	mov word ptr [bx+02],ax
1364
1365	; Store number of heads per cylinder
1366	mov bx, offset BIOS_Heads
1367	add bx,dx
1368	mov ax,[si+08h]
1369	mov word ptr [bx+00],ax
1370	mov ax,[si+0ah]
1371	mov word ptr [bx+02],ax
1372
1373	; Store number of sectors per track
1374	mov bx, offset BIOS_Secs
1375	add bx,dx
1376	mov ax,[si+0ch]
1377	mov word ptr [bx+00],ax
1378
1379	; Update first byte of translation-table to conform to BIOS SPT
1380	mov byte ptr [secs_per_track_table], al
1381
1382	mov ax,[si+0eh]
1383	mov word ptr [bx+02],ax
1384
1385	; Store total secs
1386	mov bx, offset BIOS_TotalSecs
1387	add bx,dx
1388	add bx,dx
1389	mov ax,[si+10h]
1390
1391	mov word ptr [bx+00],ax
1392	mov ax,[si+12h]
1393	mov word ptr [bx+02],ax
1394	mov ax,[si+14h]
1395	mov word ptr [bx+04],ax
1396	mov ax,[si+18h]
1397	mov word ptr [bx+06],ax
1398
1399	; Store number of bytes per sector
1400	mov bx, offset BIOS_Bytes
1401	add bx,dx
1402	mov ax,[si+18h]
1403	mov [bx],ax
1404
1405
1406	;
1407	; See of it's a huge drive of not
1408	;
1409
1410	; Drive is larger than 2TiB
1411	mov ax,5 ; Drive code (5)
1412	mov bx, [si+14h] ; Low word of high dword of sector-count
1413	or bx, [si+16h] ; High word of high dword of sector-count
1414	jnz DriveIO_GatherDiskInfo_ret ; If non-zero we have a drive with >2^32 sectors and thus LBA48 addressing
1415
1416	; Drive is larger than max OS/2 capacity
1417	dec ax ; Drive code (4)
1418	mov bx, [si+12h] ; High word of low dword of sector-count
1419	cmp bx, 0fe01h ; Boundary
1420	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1421	; we have a drive larger than to 65536255255 = FE010000 sectors
1422
1423	; Drive can be completely utilized by OS/2
1424	dec ax ; Drive code (3)
1425	cmp bx, 8000h ; Boundary
1426	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1427	; we have a drive larger than 2^31 sectors but smaller than 65536255255
1428
1429	; This is the small area between DANI 1TiB and LBA 1TiB
1430	dec ax ; Drive code (2)
1431	cmp bx, 7e81h ; Boundary
1432	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1433	; we have a drive larger than 65536255127 but <65536255255
1434	; DANIS506.ADD will use 255/255 extended geometry
1435
1436	; DANI will use 255/127 in this area, this could impact the location of LVM-sectors ! (last sec on track)
1437	dec ax ; Drive code (1)
1438	cmp bx, 3ec1h ; Boundary
1439	jae DriveIO_GatherDiskInfo_ret ; If above or equal to boundary,
1440	; we have a drive larger than 6553625563 sectors (OS/2 502GiB Limit!)
1441	; DANIS506.ADD will use 255/127 extended geometry !
1442	; IBM1S506.ADD will use 255/255 extended geometry !
1443
1444	; We have a drive that can be addressed using standard 255/63 geometry
1445	dec ax ; Drive code (0)
1446	; We have a drive smaller than 6553625563 = 3EC10000 sectors
1447
1448	DriveIO_GatherDiskInfo_ret:
1449	pop es
1450	pop di
1451	pop si
1452	pop dx
1453	pop cx
1454	pop bx
1455
1456	mov byte ptr [CurIO_UseExtension],1
1457
1458	popf
1459	ret
1460	DriveIO_GatherDiskInfo EndP
1461
1462
1463
1464	; Values for sectors per track table corresponding to DriveIO_IsHugeDrive return value.
1465	secs_per_track_table db 63,127,255,255,255,255
1466
1467	;db_lmlvm: db 'Load Master LVM -- disk: ',0

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