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driveio.asm

Last change on this file was 217, checked in by Ben Rietbroek, 8 years ago

Skip disks with a LUKS Signature [v1.1.3-testing]

This is a quick-n-dirty hack to skip LUKS encrypted disks.
LUKS disks are not truly recognized and this hack has the semantics of
the disk having no partitions.

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-v1.1.2-manual.pdf

File size: 76.4 KB

Rev	Line
[29]	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	;
[8]	18	;---------------------------------------------------------------------------
	19	; AiR-BOOT / DRIVE I/O
	20	;---------------------------------------------------------------------------
	21
[30]	22
	23
[51]	24	IFDEF MODULE_NAMES
[30]	25	DB 'DRIVEIO',0
	26	ENDIF
	27
[95]	28	;
	29	; Check if INT13X extensions are supported.
	30	; AirBoot requires these extensions, and will halt if they are not available.
[140]	31	; Modified: [CurIO_UseExtension]
	32	DriveIO_CheckFor13extensions Proc Near Uses ax bx cx dx
[95]	33	mov ah, 41h
	34	mov bx, 55AAh
	35	mov dl, [BIOS_BootDisk] ; We check using the boot-disk
	36	int 13h
[175]	37	sti
[117]	38
	39	IFDEF AUX_DEBUG
	40	IF 0
[123]	41	DBG_TEXT_OUT_AUX 'DriveIO_CheckFor13extensions:'
	42	PUSHRF
[117]	43	call DEBUG_DumpRegisters
	44	;~ call AuxIO_DumpParagraph
	45	;~ call AuxIO_TeletypeNL
[134]	46	mov si, offset [Scratch]
[117]	47	mov word ptr [si], 50h
	48	mov ah, 48h
	49	int 13h
[175]	50	sti
[117]	51	call DEBUG_DumpRegisters
	52	;~ call AuxIO_DumpSector
[123]	53	POPRF
[117]	54	ENDIF
	55	ENDIF
	56
[95]	57	jc PCCF13E_NotFound ; Error occured
	58	cmp bx, 0AA55h
	59	je PCCF13E_Found
	60	PCCF13E_NotFound:
	61	ret
	62	PCCF13E_Found:
	63	and cx, 1 ; Check 42h-44h,47h,48h supported
	64	jz PCCF13E_NotFound ; Sig OK but no support, strange beast
	65	mov byte ptr [CurIO_UseExtension], 1
	66	ret
	67	DriveIO_CheckFor13extensions EndP
	68
	69
[29]	70	; Note: Some routines set DS/ES to CS or even address via CS, even if its not
	71	; needed. This was done for SECURITY. So DO NOT remove it.
	72	; Its there to make sure the correct data is loaded/written to/from
	73	; harddrive.
[8]	74	;
[29]	75	; IF YOU MODIFY ANYTHING IN HERE, YOU MAY EASILY BREAK YOUR HARDDRIVE!
[8]	76
	77	; Will only load base-configuration, will NOT load IPT nor Hide-Config
	78	; Those are originally loaded on startup and will NOT get reloaded.
[43]	79	DriveIO_LoadConfiguration Proc Near Uses ax bx cx dx es
[111]	80
	81	IFDEF AUX_DEBUG
	82	IF 0
[123]	83	DBG_TEXT_OUT_AUX 'DriveIO_LoadConfiguration:'
	84	PUSHRF
[111]	85	;~ call DEBUG_DumpRegisters
	86	;~ call AuxIO_DumpParagraph
	87	;~ call AuxIO_TeletypeNL
[123]	88	POPRF
[111]	89	ENDIF
	90	ENDIF
	91
[123]	92	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[43]	93	mov ax, cs
	94	mov es, ax
	95	mov bx, offset Configuration
[78]	96	xor dh, dh
	97	mov dl, [BIOS_BootDisk] ; Disk we booted from
	98	mov cx, 0037h ; Sector 55 (CHS)
[43]	99	mov ax, 0201h ; Function 02, read 1 sector...
	100	int 13h
[175]	101	sti ; Enable ints
[43]	102	jnc DIOLC_NoError
	103	call MBR_LoadError ; Will Abort BootUp
[123]	104
	105
[43]	106	DIOLC_NoError:
	107	ret
	108	DriveIO_LoadConfiguration EndP
[8]	109
[43]	110	DriveIO_SaveConfiguration Proc Near Uses ax bx cx dx ds es si
[111]	111
	112	IFDEF AUX_DEBUG
	113	IF 0
[123]	114	DBG_TEXT_OUT_AUX 'DriveIO_SaveConfiguration:'
	115	PUSHRF
[164]	116	call DEBUG_DumpRegisters
[111]	117	;~ call AuxIO_DumpParagraph
	118	;~ call AuxIO_TeletypeNL
[123]	119	POPRF
[111]	120	ENDIF
	121	ENDIF
	122
[43]	123	mov ax, cs
	124	mov ds, ax
	125	mov es, ax ; Safety first (CS==DS==ES)
	126	; --- Overwrite Floppy-Name with "FloppyDrive"
	127	mov si, offset TXT_Floppy_Drive
	128	mov di, offset PartitionTable
	129	sub di, 30 ; Adjust to Floppy-Name
	130	mov cx, 11
	131	rep movsb
	132	mov si, offset Configuration ; Calculate new checksum
	133	xor bx, bx
[31]	134
[43]	135	; Changed from 5 to calculated value (not here, see compat. issue below)
	136	; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
	137	; Size of the ab-configuration in 512 byte sectors
	138	;mov cx, (MBR_BackUpMBR - Configuration) / 200h
[31]	139
[43]	140	; AB v1.07 stores a 5 sector configuration with a 5 sector checksum.
[54]	141	; AB v1.0.8+ should stores a 7 sector configuration with a
[43]	142	; 7 sector checksum.
[54]	143	; Because 5 was hardcoded here, SET(A)BOOT v1.07 will see see an AB v1.0.8+
[43]	144	; config as corrupted, while this is not the case.
[54]	145	; So, for compatibility reasons, in v1.0.8+, the checksum stored is over
[43]	146	; 5 sectors, to be compatible with v1.07.
	147	; This may change (be corrected) in future versions !
	148	mov cx,5
[32]	149
[43]	150	mov dx, [CFG_CheckConfig]
	151	mov [CFG_CheckConfig], bx
	152	DIOSC_Loop:
	153	call MBR_GetCheckOfSector
	154	loop DIOSC_Loop
	155	mov [CFG_CheckConfig], bx
	156	; --------------------------------------------------------------------
	157	; ES == CS
	158	mov bx, offset Configuration
[78]	159	xor dh, dh
	160	mov dl, [BIOS_BootDisk] ; Disk we booted from
	161	mov cx, 0037h ; Sector 55 (CHS)
[31]	162
[43]	163	; Changed from 5 to calculated value
	164	; Fixes issue: #2987 -- "air-boot doesn't remember drive letter"
	165	; Size of the ab-configuration in 512 byte sectors
	166	mov al, (MBR_BackUpMBR - Configuration) / 200h
	167	mov ah,03h
[123]	168	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[43]	169	int 13h
[175]	170	sti
[43]	171	jnc DIOSC_NoError
	172	call MBR_SaveError ; Will Abort BootUp
	173	DIOSC_NoError:
	174	ret
	175	DriveIO_SaveConfiguration EndP
[8]	176
[43]	177	DriveIO_UpdateFloppyName Proc Near Uses bx cx dx ds si es di
	178	mov ax, cs
	179	mov ds, ax
	180	mov es, ax
[8]	181
[49]	182	mov ah, 00h ; Function 0 - Reset Drive
[43]	183	xor dl, dl
	184	int 13h
[175]	185	sti
[43]	186	xor dx, dx ; Cylinder=0, Head=0
	187	mov cx, 1 ; Sector=1, Drive=0
	188	mov bx, offset TmpSector ; ES:BX - TmpSector
	189	mov ax, 0201h ; Function 2 - Load Sector
	190	int 13h
	191	jnc DIOUFN_AllFine
[8]	192
[43]	193	; --- Overwrite Floppy-Name with "No Disc"
	194	mov si, offset TXT_Floppy_NoDisc
	195	xor ax, ax
	196	DIOUFN_WriteFloppyName:
	197	mov di, offset PartitionTable
	198	sub di, 30 ; Adjust to Floppy-Name
	199	mov cl, 11
	200	rep movsb
	201	ret ; AX=-1 -> GotDisc, =0 -> NoDisc
[8]	202
[43]	203	; --- Floppy found and read, data in TempSector
	204	DIOUFN_AllFine:
	205	mov ax, -1
	206	mov si, offset TXT_Floppy_NoName
	207	cmp wptr es:[bx+54], 'AF'
	208	jne DIOUFN_WriteFloppyName
	209	cmp wptr es:[bx+56], '1T'
	210	jne DIOUFN_WriteFloppyName
	211	cmp bptr es:[bx+58], '2'
	212	jne DIOUFN_WriteFloppyName
	213	mov si, bx
	214	add si, 43 ; FAT12 - Volume Label Location
	215	jmp DIOUFN_WriteFloppyName
	216	DriveIO_UpdateFloppyName EndP
[8]	217
	218	; =============================================================================
	219	; HARDDRIVE / GENERAL ACCESS
	220	; =============================================================================
	221	; The following routines are used for harddisc/floppy access.
[26]	222	; The access is done via INT 13h/CHS or INT 13h/LBA.
	223	; Access will be done prefered by INT 13h/CHS, because it's (I wonder!) much
[8]	224	; faster, than the LBA-method. I don't know, why LBA is so slow. Perhaps BIOS.
	225	;
[26]	226	; Internal access (to AiR-BOOT) is always done via INT 13h/CHS.
[8]	227
[43]	228	DriveIO_GetHardDriveCount Proc Near Uses ds si
	229	push ds
	230	push si
	231	push 0040h
	232	pop ds
	233	mov si, 0075h
[164]	234	mov dh, ds:[si] ; 40:75 -> POST: Total Harddiscs == DH
[43]	235	pop si
	236	pop ds
[51]	237	mov [TotalHarddiscs], dh
[43]	238	ret
	239	DriveIO_GetHardDriveCount EndP
[29]	240
	241
	242	; Fills our LBA-Usage table. It holds the LBA-address, where BIOS/CHS access is
	243	; stopped and BIOS/LBA access is started.
	244	; This is calculated by Sector*Heads. Comparing will get done with Bit 25-10
	245	; on LBA sectors, so we actually divide sector number by 1024.
[43]	246	DriveIO_InitLBASwitchTable Proc Near Uses es di
	247	mov di, offset LBASwitchTable
[51]	248	mov dh, [TotalHarddiscs]
[78]	249	mov dl, 80h ; First disk to process
[43]	250	DIOILUT_DriveLoop:
	251	push dx
	252	push di
	253	mov ah, 08h
	254	int 13h ; DISK - GET DRIVE PARAMETERS
[175]	255	sti ; Enable ints
[43]	256	mov ah, 0FBh ; Assume 255 heads/63 sectors, if error
	257	jc DIOILUT_Error
	258	and cl, 111111b ; Isolate lower 6 bits of CL -> sector count
[123]	259	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[43]	260	;movzx ax, cl
	261	mov al,cl
	262	mov ah,0
[30]	263
[43]	264	mov bl, dh ; DH -> max head number
	265	mul bl ; AX = Sectors*Heads
	266	shl ah, 1
	267	shl ah, 1 ; Shift 2 bits, so we are able to compare to
	268	; bit 16-23 of the LBA address
	269	DIOILUT_Error:
	270	pop di
	271	pop dx
	272	mov bptr ds:[di], ah ; Save that value
	273	inc di ; Go to next BYTE
[78]	274	inc dl ; Next disk
	275	dec dh ; Decrease disks to process
	276	jnz DIOILUT_DriveLoop ; Next disk if DH != 0
[43]	277	ret
	278	DriveIO_InitLBASwitchTable EndP
[29]	279
[30]	280	; #########################################################################
	281	; Routine: Loads partition to ExecBase and checks for validity
	282	; #########################################################################
	283	; Calling : bx:ax - Absolute sector
	284	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
	285	; Returns : Carry Set if invalid partition encountered
	286	; Preserve: all registers
	287	; #########################################################################
[43]	288	DriveIO_LoadPartition Proc Near Uses si
[117]	289
	290	IFDEF AUX_DEBUG
	291	IF 0
[123]	292	DBG_TEXT_OUT_AUX 'DriveIO_LoadPartition:'
	293	PUSHRF
[117]	294	call DEBUG_DumpRegisters
	295	;~ call AuxIO_DumpParagraph
	296	;~ call AuxIO_TeletypeNL
[123]	297	POPRF
[117]	298	ENDIF
	299	ENDIF
	300
[43]	301	mov wptr cs:[CurPartition_Location+0], ax
	302	mov wptr cs:[CurPartition_Location+2], bx
	303	mov wptr cs:[CurPartition_Location+4], dx
	304	mov wptr cs:[CurPartition_Location+6], cx ; Saves the location
[164]	305	mov si, offset [PartitionSector] ; DS:SI - ExecBase
[123]	306
	307
	308	;!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[43]	309	call DriveIO_LoadSector
[123]	310
[216]	311	; ----------------------------------------------------- [Check for GPT]
	312	; Check the 4 P-Table entries for a GPT identifier
	313	; If found, set CY and exit to indicate no partitions are found.
	314	; This prevents the disk from appearing in the menu with an 'unknown'
	315	; partition identifier.
	316	cmp byte ptr [si+01c2h], 0eeh ; Check Entry #1
	317	stc
	318	jz DIOLP_Success
	319	cmp byte ptr [si+01d2h], 0eeh ; Check Entry #2
	320	stc
	321	jz DIOLP_Success
	322	cmp byte ptr [si+01e2h], 0eeh ; Check Entry #3
	323	stc
	324	jz DIOLP_Success
	325	cmp byte ptr [si+01f2h], 0eeh ; Check Entry #4
	326	stc
	327	jz DIOLP_Success
	328
[217]	329	; ---------------------------------------------------- [Check for LUKS]
	330	; Check for LUKS signature
	331	; If the LUKS signature is foud, set CY and exit to indicate no
	332	; are found partitions. This prevents LUKS disks from appearing in the
	333	; menu in the off chance the luks-sector has a 0xaa55 at offset 0x01fe.
	334	cmp word ptr [si+00h], 554ch ; 'LU'
	335	jne @F
	336	cmp word ptr [si+02h], 534bh ; 'KS'
	337	stc
	338	jz DIOLP_Success
	339
	340	@@:
[43]	341	clc
	342	cmp wptr [si+LocBR_Magic], 0AA55h
	343	je DIOLP_Success
	344	; We check, if we are scanning partitions. In that case, if CHS is not 0/0/1
	345	; we will display a "bad partition table" message and halt the system.
	346	cmp cx, 0001h
	347	jne DIOLP_Failed
	348	or dh, dh
	349	jnz DIOLP_Failed
	350	stc ; Set carry, so no partition table
	351	DIOLP_Success:
[30]	352
	353
[117]	354
[43]	355	ret
	356	DIOLP_Failed:
	357	jmp DriveIO_GotLoadError
	358	DriveIO_LoadPartition EndP
[8]	359
[30]	360	; #########################################################################
	361	; Routine: Writes a partition from ExecBase to its original sector
	362	; #########################################################################
	363	; Calling : none
	364	; Returns : none
	365	; Preserve: all registers
	366	; #########################################################################
[43]	367	DriveIO_SavePartition Proc Near Uses ax bx cx dx si
[111]	368
	369	IFDEF AUX_DEBUG
	370	IF 0
[123]	371	DBG_TEXT_OUT_AUX 'DriveIO_SavePartition:'
	372	PUSHRF
[164]	373	call DEBUG_DumpRegisters
[111]	374	;~ call AuxIO_DumpParagraph
	375	;~ call AuxIO_TeletypeNL
[123]	376	POPRF
[111]	377	ENDIF
	378	ENDIF
	379
[43]	380	mov ax, wptr cs:[CurPartition_Location+0]
	381	mov bx, wptr cs:[CurPartition_Location+2]
	382	mov dx, wptr cs:[CurPartition_Location+4]
	383	mov cx, wptr cs:[CurPartition_Location+6] ; Gets prev. saved location
	384	mov si, offset PartitionSector ; DS:SI - ExecBase
	385	cmp wptr [si+LocBR_Magic], 0AA55h ; Checks for signature, if not found
	386	jne DIOSP_SevereError ; we assume a really bad error
	387	call DriveIO_SaveSector
	388	DIOSP_SevereError:
	389	ret
	390	DriveIO_SavePartition EndP
[8]	391
	392
	393
[147]	394	;##############################################################################
	395	;# The location of LVM sectors depends on the OS/2 geometry used when the disk
	396	;# was prepared. This geometry is present in the Master LVM sector, which has
	397	;# already been located if it exists. All partitions, whether primary or
	398	;# logical, have an entry in a partition table. For primary partitions this
	399	;# table is located in the MBR, while for logical partitions this table is
	400	;# located in the EBR for that logical partition. An LVM record is located
	401	;# LVM_SPT-1 sectors above an MBR or EBR. The Master LVM record contains the
	402	;# information for all primary partitions. For logical partitions, the LVM
	403	;# sector only has one entry, because EBRs are chained. The global LVM info,
	404	;# like disk-name, sectors per track, etc. is replicated between the Master
	405	;# LVM sector and LVM sectors corresponding to logical partitions. This info
	406	;# is kept in sync by the OS/2 LVM Engine.
	407	;##############################################################################
	408	;# ACTION : Attempts to load the corresponding LVM sector for a partition
	409	;# ----------------------------------------------------------------------------
	410	;# EFFECTS : Modifies DAP structure and fills or clears sector buffer
	411	;# ----------------------------------------------------------------------------
[149]	412	;# IN : MEM - Location info is in [CurPartition_Location]
[147]	413	;# ----------------------------------------------------------------------------
[149]	414	;# OUT : CF=1 - failure, no valid LVM sector was loaded
	415	;# : SI - Points to the sector buffer ([LVMSector])
[147]	416	;##############################################################################
	417	DriveIO_LoadLVMSector Proc Near Uses ax bx cx dx di
[111]	418
	419	IFDEF AUX_DEBUG
[152]	420	IF 0
[123]	421	DBG_TEXT_OUT_AUX 'DriveIO_LoadLVMSector:'
	422	PUSHRF
[117]	423	call DEBUG_DumpRegisters
[147]	424	;~ call AuxIO_DumpSector
[111]	425	;~ call AuxIO_DumpParagraph
	426	;~ call AuxIO_TeletypeNL
[123]	427	POPRF
[111]	428	ENDIF
	429	ENDIF
	430
[147]	431	; Clear the sector buffer
	432	mov si, offset [LVMSector]
	433	call ClearSectorBuffer
[30]	434
[147]	435	; Quit with CY if LVM is ignored in SETUP
	436	test byte ptr [CFG_IgnoreLVM], 1 ; ZF=0 means ignore LVM
	437	jnz DIOLLVMS_NoLVMSector ; Quit if so
[30]	438
[147]	439	; Load the location of the current partition being acted upon.
	440	; Note that this is not the actual LBA of the partition, but the
	441	; sector that has the partition table that contains the entry
	442	; for the partition. In other words, for primary partitions the LBA
	443	; address points to the MBR while for extended partitions it points
	444	; to an EBR. In both cases the LVM sector is located LVM_SPT-1 above.
	445	; Also note that the BIOS CHS values (DH and CX) below are not used,
	446	; because we explicitly use LBA sector loading.
	447	mov ax, wptr cs:[CurPartition_Location+0] ; LBA lo of MBR/EBR
	448	mov bx, wptr cs:[CurPartition_Location+2] ; LBA hi of MBR/EBR
	449	mov dx, wptr cs:[CurPartition_Location+4] ; BIOS disk num & head
	450	mov cx, wptr cs:[CurPartition_Location+6] ; BIOS cyl & sec
	451
[152]	452	; Do the actual loading.
	453	; This is in a separate function so that LVM records can also be
	454	; loaded using the MBR/EBR LBA addresses from IPT entries.
	455	call DriveIO_LoadLVMSectorXBR
	456	jc DIOLLVMS_NoLVMSector
	457
	458	; We're done, indicate success and return
	459	clc
	460	jmp DIOLLVMS_Done
	461
	462	DIOLLVMS_NoLVMSector:
	463
	464	; Clear the sector buffer
	465	mov si, offset [LVMSector]
	466	call ClearSectorBuffer
	467	mov bptr [si+LocLVM_SignatureStart], 0
	468
	469	; Indicate no valid LVM sector was loaded
	470	stc
	471
	472	DIOLLVMS_Done:
	473
	474	ret
	475	DriveIO_LoadLVMSector EndP
	476
	477
	478
	479
	480
	481	;------------------------------------------------------------------------------
	482	; Attempts to load the corresponding LVM sector for a partition
	483	;------------------------------------------------------------------------------
	484	; IN : AX - LBA lo of MBR or EBR
	485	; : BX - LBA hi of MBR or EBR
	486	; ; DL - BIOS disk number
	487	; ; SI - Pointer to sector buffer (usually [LVMSec])
	488	; OUT : CF=0 - A valid LVM sector was loaded
	489	; NOTE : LocIPT_AbsolutePartTable and LocIPT_Drive can provide LBA and DISK
	490	;------------------------------------------------------------------------------
	491	DriveIO_LoadLVMSectorXBR Proc Near
	492
	493	IFDEF AUX_DEBUG
[164]	494	IF 0
[152]	495	DBG_TEXT_OUT_AUX 'DriveIO_LoadLVMSectorXBR:'
	496	PUSHRF
	497	call DEBUG_DumpRegisters
	498	;~ call AuxIO_DumpSector
	499	;~ call AuxIO_DumpParagraph
	500	;~ call AuxIO_TeletypeNL
	501	POPRF
	502	ENDIF
	503	ENDIF
	504
	505	; Save all registers
	506	pusha
	507
[149]	508	; Calculate the entry in the DISKINFO array for this disk,
	509	; and put the LVM_SPT in DI
	510	push bx
	511	call DriveIO_CalcDiskInfoPointer
	512	mov di, [bx+LocDISKINFO_LVM_Secs]
	513	pop bx
	514
	515	; If the LVM_SPT is ZERO, no LVM info is present and we quit with CY
	516	test di, di ; See if it is 0
[152]	517	jz DriveIO_LoadLVMSectorXBR_no_lvm ; Quit if so
[149]	518
[147]	519	; Adjust the location to point to the LVM sector
	520	add ax, di ; Add the LVM sectors-per-track
	521	adc bx, 0 ; Propagate LBA lo overflow to LBA hi
	522	sub ax, 1 ; LVM sector is located one sector below
	523	sbb bx, 0 ; Propagate borrow to LBA hi
	524
[152]	525	; Load the LVM sector into sector buffer pointed to by SI
[147]	526	mov di, ds ; Segment of that buffer
	527	call DriveIO_ReadSectorLBA ; Read the LVM sector
	528
[117]	529	IFDEF AUX_DEBUG
[164]	530	IF 0
[149]	531	DBG_TEXT_OUT_AUX 'LVMSecLoaded'
[123]	532	PUSHRF
[147]	533	call DEBUG_DumpRegisters
[152]	534	;~ call AuxIO_DumpSector
	535	mov cx, 3
	536	@@:
	537	call AuxIO_DumpParagraph
	538	call AuxIO_TeletypeNL
	539	add si, 16
	540	loop @B
[147]	541	;~ call AuxIO_DumpParagraph
[117]	542	;~ call AuxIO_TeletypeNL
[123]	543	POPRF
[117]	544	ENDIF
	545	ENDIF
[30]	546
[152]	547	jc DriveIO_LoadLVMSectorXBR_no_lvm ; Quit on error
[149]	548
	549	; Check the validity of the LVM sector, quit with CY if invalid
	550	call LVM_ValidateSector ; Check signature and CRC
[152]	551	jnc DriveIO_LoadLVMSectorXBR_no_lvm ; Quit if not valid
[149]	552
[147]	553	; We're done, indicate success and return
	554	clc
[152]	555	jmp DriveIO_LoadLVMSectorXBR_done
[117]	556
[152]	557	DriveIO_LoadLVMSectorXBR_no_lvm:
[147]	558	; Indicate no valid LVM sector was loaded
	559	stc
	560
[152]	561	DriveIO_LoadLVMSectorXBR_done:
	562	; Restore all registers
	563	popa
[147]	564
[43]	565	ret
[152]	566	DriveIO_LoadLVMSectorXBR EndP
[29]	567
[51]	568
[150]	569	;##############################################################################
	570	;# The location of LVM sectors depends on the OS/2 geometry used when the disk
	571	;# was prepared. This geometry is present in the Master LVM sector, which has
	572	;# already been located if it exists. All partitions, whether primary or
	573	;# logical, have an entry in a partition table. For primary partitions this
	574	;# table is located in the MBR, while for logical partitions this table is
	575	;# located in the EBR for that logical partition. An LVM record is located
	576	;# LVM_SPT-1 sectors above an MBR or EBR. The Master LVM record contains the
	577	;# information for all primary partitions. For logical partitions, the LVM
	578	;# sector only has one entry, because EBRs are chained. The global LVM info,
	579	;# like disk-name, sectors per track, etc. is replicated between the Master
	580	;# LVM sector and LVM sectors corresponding to logical partitions. This info
	581	;# is kept in sync by the OS/2 LVM Engine.
	582	;##############################################################################
	583	;# ACTION : Attempts to save the corresponding LVM sector for a partition
	584	;# ----------------------------------------------------------------------------
	585	;# EFFECTS : Modifies DAP structure and writes LVM sector to disk
	586	;# ----------------------------------------------------------------------------
	587	;# IN : MEM - Location info is in [CurPartition_Location]
	588	;# : SI - Pointer to sector buffer
	589	;# ----------------------------------------------------------------------------
	590	;# OUT : CF=1 - failure, no valid LVM sector was saved
	591	;##############################################################################
	592	DriveIO_SaveLVMSector Proc Near Uses ax bx cx dx di
[111]	593
	594	IFDEF AUX_DEBUG
[152]	595	IF 0
[123]	596	DBG_TEXT_OUT_AUX 'DriveIO_SaveLVMSector:'
	597	PUSHRF
[150]	598	call DEBUG_DumpRegisters
[111]	599	;~ call AuxIO_DumpParagraph
	600	;~ call AuxIO_TeletypeNL
[123]	601	POPRF
[111]	602	ENDIF
	603	ENDIF
	604
[150]	605	; Quit with CY if LVM is ignored in SETUP
	606	test byte ptr [CFG_IgnoreLVM], 1 ; ZF=0 means ignore LVM
[152]	607	jnz DIOSLVMS_NoLVMSector ; Quit if so
[50]	608
[150]	609	; Load the location of the current partition being acted upon.
	610	; Note that this is not the actual LBA of the partition, but the
	611	; sector that has the partition table that contains the entry
	612	; for the partition. In other words, for primary partitions the LBA
	613	; address points to the MBR while for extended partitions it points
	614	; to an EBR. In both cases the LVM sector is located LVM_SPT-1 above.
	615	; Also note that the BIOS CHS values (DH and CX) below are not used,
	616	; because we explicitly use LBA sector loading.
	617	mov ax, wptr cs:[CurPartition_Location+0] ; LBA lo of MBR/EBR
	618	mov bx, wptr cs:[CurPartition_Location+2] ; LBA hi of MBR/EBR
	619	mov dx, wptr cs:[CurPartition_Location+4] ; BIOS disk num & head
	620	mov cx, wptr cs:[CurPartition_Location+6] ; BIOS cyl & sec
[50]	621
[152]	622	; Do the actual saving.
	623	; This is in a separate function so that LVM records can also be
	624	; saved using the MBR/EBR LBA addresses from IPT entries.
	625	call DriveIO_SaveLVMSectorXBR
	626	jc DIOSLVMS_NoLVMSector
	627
	628	; We're done, indicate success and return
	629	clc
	630	jmp DIOSLVMS_Done
	631
	632	DIOSLVMS_NoLVMSector:
	633	; Indicate no valid LVM sector was saved
	634	stc
	635
	636	DIOSLVMS_Done:
	637	ret
	638	DriveIO_SaveLVMSector EndP
	639
	640
	641	;------------------------------------------------------------------------------
	642	; Attempts to save the corresponding LVM sector for a partition
	643	;------------------------------------------------------------------------------
	644	; IN : AX - LBA lo of MBR or EBR
	645	; : BX - LBA hi of MBR or EBR
	646	; ; DL - BIOS disk number
	647	; ; SI - Pointer to sector buffer (usually [LVMSec])
	648	; OUT : CF=0 - A valid LVM sector was saved
	649	; NOTE : LocIPT_AbsolutePartTable and LocIPT_Drive can provide LBA and DISK
	650	;------------------------------------------------------------------------------
	651	DriveIO_SaveLVMSectorXBR Proc Near
	652
[157]	653	IFDEF AUX_DEBUG
[169]	654	IF 1
[157]	655	DBG_TEXT_OUT_AUX 'DriveIO_SaveLVMSectorXBR:'
	656	PUSHRF
	657	call DEBUG_DumpRegisters
[169]	658	call AuxIO_DumpSector
[157]	659	;~ call AuxIO_DumpParagraph
	660	;~ call AuxIO_TeletypeNL
	661	POPRF
	662	ENDIF
	663	ENDIF
	664
[152]	665	; Save all registers
	666	pusha
	667
	668	; Check the validity of the LVM sector, quit with CY if invalid
	669	push ax ; Save LBA lo
	670	call LVM_ValidateSector ; Check signature and CRC
	671	pop ax ; Restore LBA lo
	672	jnc DriveIO_SaveLVMSectorXBR_no_lvm ; Quit if not valid
	673
[150]	674	; Calculate the entry in the DISKINFO array for this disk,
	675	; and put the LVM_SPT in DI
	676	push bx
	677	call DriveIO_CalcDiskInfoPointer
	678	mov di, [bx+LocDISKINFO_LVM_Secs]
	679	pop bx
	680
	681	; If the LVM_SPT is ZERO, no LVM info is present and we quit with CY
	682	test di, di ; See if it is 0
[152]	683	jz DriveIO_SaveLVMSectorXBR_no_lvm ; Quit if so
[150]	684
	685	; Adjust the location to point to the LVM sector
	686	add ax, di ; Add the LVM sectors-per-track
	687	adc bx, 0 ; Propagate LBA lo overflow to LBA hi
	688	sub ax, 1 ; LVM sector is located one sector below
	689	sbb bx, 0 ; Propagate borrow to LBA hi
	690
[169]	691	; Writing an LVM sector is always the result of modifications to a
	692	; previously loaded one. So, now that we have the LBA address of the
	693	; LVM sector, the one about to be overwritten should be there.
	694	; If it's not, something is seriously wrong and we quit immetiately.
	695	pusha ; Push our context except the flags
	696	mov si, offset [Scratch] ; Sector buffer to load the LVM sector
	697	call ClearSectorBuffer ; Make sure no old LVM info is present
	698	mov di, ds ; Segment of buffer
	699	call DriveIO_ReadSectorLBA ; Load the old LVM sector
	700	call LVM_ValidateSector ; CF=1 if valid
	701	cmc ; Complement for disk i/o semantics
	702	popa ; Restore our context except the flags
	703
	704	; OOPS, There was no LVM sector there !!
	705	jc DriveIO_SaveLVMSectorXBR_no_lvm
	706
[152]	707	; Save the LVM sector pointed to by SI
	708	mov di, ds ; Segment of that buffer
[169]	709	call DriveIO_WriteSectorLBA ; Write the LVM sector
[152]	710
[117]	711	IFDEF AUX_DEBUG
[169]	712	IF 1
[150]	713	DBG_TEXT_OUT_AUX 'LVMSecSaved'
	714	PUSHRF
[117]	715	call DEBUG_DumpRegisters
[150]	716	call AuxIO_DumpSector
	717	;~ call AuxIO_DumpParagraph
	718	;~ call AuxIO_TeletypeNL
	719	POPRF
[117]	720	ENDIF
	721	ENDIF
[50]	722
[152]	723	jc DriveIO_SaveLVMSectorXBR_no_lvm ; Quit on error
[150]	724
	725	; We're done, indicate success and return
	726	clc
[152]	727	jmp DriveIO_SaveLVMSectorXBR_done
[150]	728
[152]	729	DriveIO_SaveLVMSectorXBR_no_lvm:
[169]	730	; Indicate no valid LVM sector was saved
[150]	731	stc
	732
[152]	733	DriveIO_SaveLVMSectorXBR_done:
	734	; Restore all registers
	735	popa
	736
[43]	737	ret
[152]	738	DriveIO_SaveLVMSectorXBR EndP
[29]	739
[43]	740
[8]	741
[26]	742	; Special error message instead of "LOAD ERROR" during partition scanning,
	743	; so users will notice that something is bad with their partition table(s)
[43]	744	DriveIO_GotLoadError Proc Near
[170]	745	IFDEF AUX_DEBUG
	746	IF 1
	747	DBG_TEXT_OUT_AUX 'DriveIO_GotLoadError:'
	748	PUSHRF
	749	call DEBUG_DumpRegisters
	750	;~ call AuxIO_DumpParagraph
	751	;~ call AuxIO_TeletypeNL
	752	POPRF
	753	ENDIF
	754	ENDIF
[46]	755	test byte ptr cs:[CurIO_Scanning], 1 ; Must be CS:, cause DS!=CS maybe here
[43]	756	jnz InScanMode
	757	jmp MBR_LoadError
	758	InScanMode:
	759	mov si, offset TXT_BrokenPartitionTable
	760	push cs
	761	pop ds
	762	call MBR_Teletype
	763	mov si, offset BrokenHDD
	764	sub dl, 50h ; 80h -> '0'
	765	cmp dl, 39h
	766	jbe DIOGLE_BelowA
	767	add dl, 7 ; 3Ah -> 'A'
	768	DIOGLE_BelowA:
	769	mov bptr [si+5], dl
	770	call MBR_Teletype
[40]	771
[43]	772	; JWasm: cannot jump to local label in other procedure.
	773	; Changed to halt here.
	774	;jmp MBRLE_Halt
	775	DriveIO_GotLoadError_halt:
	776	jmp DriveIO_GotLoadError_halt
	777	DriveIO_GotLoadError EndP
[26]	778
[30]	779	; #########################################################################
	780	; Routine: Loads a specified sector to DS:DI
	781	; #########################################################################
	782	; Calling : bx:ax - Absolute sector
	783	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
	784	; ds:si - Destination-Adress
	785	; Returns : none
	786	; Preserve: all registers
	787	; #########################################################################
[51]	788	DriveIO_LoadSector Proc Near Uses ax bx cx dx ds si es di
[110]	789
[111]	790	IFDEF AUX_DEBUG
	791	IF 0
[123]	792	DBG_TEXT_OUT_AUX 'DriveIO_LoadSector:'
	793	PUSHRF
[117]	794	call DEBUG_DumpRegisters
[111]	795	;~ call AuxIO_DumpParagraph
	796	;~ call AuxIO_TeletypeNL
[123]	797	POPRF
[111]	798	ENDIF
	799	ENDIF
	800
[43]	801	; Is the drive not a harddrive?
	802	cmp dl, 80h
	803	jb DIOLS_UseNormal
[36]	804
[46]	805	test byte ptr cs:[CurIO_UseExtension], 1
[43]	806	jz DIOLS_UseNormal
	807	; Are we forced do use LBA via Setting?
	808	jnz DIOLS_UseExtension
[36]	809
[51]	810	; Upper 8 bits of LBA-address set?
	811	; Then use LBA (maximum boundary is 16320x16x63 = FB0400h)
[43]	812	or bh, bh
	813	jnz DIOLS_UseExtension
	814	; Compare Switch-Table value to bit 16-23 of LBA-address
	815	mov di, dx
	816	and di, 007Fh
	817	cmp bptr cs:[LBASwitchTable+di], bl
	818	jbe DIOLS_UseExtension
[111]	819
[43]	820	DIOLS_UseNormal:
[111]	821
	822	IFDEF AUX_DEBUG
	823	IF 0
[123]	824	DBG_TEXT_OUT_AUX 'DriveIO_ReadSectorCHS:'
	825	PUSHRF
[111]	826	call DEBUG_DumpRegisters
	827	call AuxIO_DumpParagraph
	828	call AuxIO_TeletypeNL
[123]	829	POPRF
[111]	830	ENDIF
	831	ENDIF
	832
	833	mov di, 3 ; retry count
[43]	834	DIOLS_ErrorLoop:
	835	push ds
	836	pop es
	837	mov bx, si ; ES:BX - Destination
	838	mov ax, 0201h ; Function 2 - Load Sector
	839	int 13h
[175]	840	sti ; enable ints
[43]	841	jnc DIOLS_Success
[111]	842	dec di ; decrement retry count
[43]	843	jnz DIOLS_ErrorLoop
[110]	844
[43]	845	; Sector load failed...
	846	jmp DriveIO_GotLoadError
[8]	847
[43]	848	DIOLS_UseExtension:
[110]	849
	850	mov di, ds ; segment for transfer address
	851	call DriveIO_ReadSectorLBA ; extended read
	852	jc DriveIO_GotLoadError ; halt on error
	853
	854	;~ push cx
	855	;~ mov cs:[INT13X_DAP_NumBlocks], 1 ; Copy ONE sector
	856	;~ mov wptr cs:[INT13X_DAP_Transfer+0], si
	857	;~ mov cx, ds
	858	;~ mov wptr cs:[INT13X_DAP_Transfer+2], cx ; Fill out Transfer Adress
	859	;~ mov wptr cs:[INT13X_DAP_Absolute+0], ax
	860	;~ mov wptr cs:[INT13X_DAP_Absolute+2], bx ; Fill out Absolute Sector
	861	;~ push cs
	862	;~ pop ds
	863	;~ mov si, offset [INT13X_DAP]
	864	;~ mov ah, 42h ; Extended Read
	865	;~ int 13h
	866	;~ pop cx
	867	;~ jnc DIOLS_Success
	868
[43]	869	; Sector load failed...
[110]	870	;~ jmp DriveIO_GotLoadError
[8]	871
[43]	872	DIOLS_Success:
[117]	873
	874	IFDEF AUX_DEBUG
	875	IF 0
[123]	876	DBG_TEXT_OUT_AUX 'sector loaded'
	877	PUSHRF
[117]	878	;~ call DEBUG_DumpRegisters
[123]	879	;~ call AuxIO_DumpSector
	880	mov cx, 32
	881	@@:
	882	call AuxIO_DumpParagraph
	883	call AuxIO_TeletypeNL
	884	add si, 16
	885	loop @B
	886	POPRF
[117]	887	ENDIF
	888	ENDIF
[43]	889	ret
	890	DriveIO_LoadSector EndP
[8]	891
[32]	892
[126]	893	;##############################################################################
	894	;# ACTION : Loads the Master Boot Record from the specified drive into buffer
	895	;# ----------------------------------------------------------------------------
	896	;# EFFECTS : Modifies DAP structure and fills or clears transfer buffer
	897	;# ----------------------------------------------------------------------------
	898	;# IN : DL - BIOS disk number (80h,81h,etc)
	899	;# : SI - Pointer to transfer buffer
	900	;# ----------------------------------------------------------------------------
	901	;# OUT : CF=1 - failure
	902	;# : AL.0 - MBR signature present
	903	;# : AL.1 - Primary partitions present
	904	;# : AL.2 - Extended partitions present
	905	;# : AL.3 - AiR-BOOT signature present
	906	;# : AL.4:7 - Reserved, returned as 0
	907	;# : AH.0:7 - Reserved, returned as 0
	908	;##############################################################################
	909	DriveIO_LoadMBR Proc Near uses bx cx dx si di
[32]	910
[126]	911	; Always clear the transfer buffer first
	912	call ClearSectorBuffer
	913
	914	; Assume an invalid MBR
	915	xor ax, ax
	916
	917	; Accept only valid harddisks
	918	call DriveIO_IsValidHarddisk
	919	jc DriveIO_LoadMBR_exit
	920
	921	; Save the address of the transfer buffer
	922	mov di, si
	923
	924	; Read the MBR from disk
	925	xor ax, ax ; LBA low
	926	xor bx, bx ; LBA high
	927	xor dh, dh ; Head 0
	928	mov cx, 1 ; Sector 1
	929	call DriveIO_LoadSector ; Read the sector from disk
	930
	931	; Check the loaded MBR for a signature
	932	xor ax, ax ; Assume an invalid MBR
	933	mov dx, [si+LocBR_Magic] ; Get word from MBR signature location
	934	cmp dx, 0aa55h ; Is it the magic value ?
	935	jne DriveIO_LoadMBR_exit ; Nope, no need to test anything else
	936
	937	; Indicate we have a MBR signature
	938	or al, 01h
	939
	940	; Advance to the partition table
	941	add si, 01beh
	942
	943	; Total of 4 entries to check
	944	mov cx, 4
	945
	946	DriveIO_LoadMBR_next_entry:
	947	mov dl, [si+LocBRPT_SystemID] ; Get partition-type / system-id
	948	add si, 10h ; Point to next entry
	949	test dl, dl ; Nothing in this one ?
	950	loopz DriveIO_LoadMBR_next_entry ; Then check next entry
	951
	952	; All entries checked and last one was also empty, we're done
	953	jz DriveIO_LoadMBR_check_ab
	954
	955	; Found a non-empty entry, set bits according to its type
	956	cmp dl, 05h ; Old style extended container ?
	957	jne @F ; Nope...
	958	or al, 04h ; Yep, mark ext. container present
	959	@@: cmp dl, 0fh ; New style extended container ?
	960	jne @F ; Nope...
	961	or al, 04h ; Yep, mark ext. container present
	962	@@: or al, 02h ; Then is must be a primary
	963	jcxz DriveIO_LoadMBR_check_ab ; CX=0? Then all entries processed,
	964	jmp DriveIO_LoadMBR_next_entry ; otherwise check next entry
	965
	966	; Check if an AiR-BOOT signature is present
	967	DriveIO_LoadMBR_check_ab:
	968	mov si, offset [MBR_ABSig] ; Offset of AiR-BOOT signature
	969	inc di ; Advance buffer pointer
	970	inc di ; to AiR-BOOT signature location
	971	mov cx, 7 ; Length of AiR-BOOT signature
	972	cld ; Direction upwards
	973	repe cmpsb ; Compare 7 bytes
	974	jne DriveIO_LoadMBR_exit ; Nope, no AiR-BOOT on this disk
	975	or al, 08h ; Yep, AiR-BOOT is on this disk
	976	;~ jmp DriveIO_LoadMBR_exit
	977
	978	DriveIO_LoadMBR_exit:
	979	ret
	980	DriveIO_LoadMBR EndP
	981
	982
[102]	983	;##############################################################################
	984	;# ACTION : Reads a sector from disk using INT13 extensions
	985	;# ----------------------------------------------------------------------------
[117]	986	;# EFFECTS : Modifies DAP structure and fills transfer buffer
	987	;# ----------------------------------------------------------------------------
[118]	988	;# IN : BX:AX - LBA address of sector
[102]	989	;# : DI:SI - SEG:OFF of transfer buffer
	990	;# ----------------------------------------------------------------------------
[118]	991	;# OUT : CF=1 - failure
[102]	992	;##############################################################################
[118]	993	DriveIO_ReadSectorLBA Proc Near
[102]	994
[111]	995	IFDEF AUX_DEBUG
	996	IF 0
[123]	997	DBG_TEXT_OUT_AUX 'DriveIO_ReadSectorLBA:'
	998	PUSHRF
[111]	999	call DEBUG_DumpRegisters
	1000	call AuxIO_DumpParagraph
	1001	call AuxIO_TeletypeNL
[123]	1002	POPRF
[111]	1003	ENDIF
	1004	ENDIF
	1005
[118]	1006	; Push all registers
	1007	pusha
	1008	push ds
	1009	push es
	1010
[102]	1011	; One sector to read
[105]	1012	mov cs:[INT13X_DAP_NumBlocks], 1
[32]	1013
[102]	1014	; Setup transfer address
[105]	1015	mov wptr cs:[INT13X_DAP_Transfer+0], si ; offset
	1016	mov wptr cs:[INT13X_DAP_Transfer+2], di ; segment
[32]	1017
[102]	1018	; Setup LBA64 address of requested sector
[118]	1019	mov wptr cs:[INT13X_DAP_Absolute+0], ax ; low word lower part
[105]	1020	mov wptr cs:[INT13X_DAP_Absolute+2], bx ; high word lower part
	1021	mov wptr cs:[INT13X_DAP_Absolute+4], 0 ; low word upper part
	1022	mov wptr cs:[INT13X_DAP_Absolute+6], 0 ; high word upper part
[32]	1023
[43]	1024	; Address of packet
[105]	1025	mov si, offset [INT13X_DAP] ; disk address packet
[32]	1026
[43]	1027	; Do the extended read
[102]	1028	mov ah, 42h ; read function
	1029	int 13h ; transfer to bios
[175]	1030	sti ; enable ints
[32]	1031
[102]	1032	; Error occured
	1033	jc DriveIO_ReadSectorLBA_exit
[32]	1034
[102]	1035	; AH should also be zero
	1036	test ah, ah
[43]	1037	stc
[102]	1038	jnz DriveIO_ReadSectorLBA_exit
[32]	1039
[102]	1040	; Disk read succeeded, clear CF
	1041	clc
[32]	1042
[102]	1043	DriveIO_ReadSectorLBA_exit:
[118]	1044
	1045	; Pop all registers
	1046	pop es
	1047	pop ds
	1048	popa
	1049
[43]	1050	ret
[102]	1051	DriveIO_ReadSectorLBA EndP
[32]	1052
	1053
[102]	1054
[103]	1055	;##############################################################################
	1056	;# ACTION : Writes a sector to disk using INT13 extensions
	1057	;# ----------------------------------------------------------------------------
[117]	1058	;# EFFECTS : Modifies DAP structure and mofifies the disk
	1059	;# ----------------------------------------------------------------------------
[118]	1060	;# IN : BX:AX - LBA address of sector
[103]	1061	;# : DI:SI - SEG:OFF of transfer buffer
	1062	;# ----------------------------------------------------------------------------
[118]	1063	;# OUT : CF=1 - failure
[103]	1064	;##############################################################################
[118]	1065	DriveIO_WriteSectorLBA Proc Near
[103]	1066
[111]	1067	IFDEF AUX_DEBUG
	1068	IF 0
[123]	1069	DBG_TEXT_OUT_AUX 'DriveIO_WriteSectorLBA:'
	1070	PUSHRF
[111]	1071	call DEBUG_DumpRegisters
	1072	call AuxIO_DumpParagraph
	1073	call AuxIO_TeletypeNL
[123]	1074	POPRF
[111]	1075	ENDIF
	1076	ENDIF
	1077
[118]	1078	; Push all registers
	1079	pusha
	1080	push ds
	1081	push es
[103]	1082
	1083	; One sector to read
[105]	1084	mov cs:[INT13X_DAP_NumBlocks], 1
[103]	1085
	1086	; Setup transfer address
[105]	1087	mov wptr cs:[INT13X_DAP_Transfer+0], si ; offset
	1088	mov wptr cs:[INT13X_DAP_Transfer+2], di ; segment
[103]	1089
	1090	; Setup LBA64 address of requested sector
[118]	1091	mov wptr cs:[INT13X_DAP_Absolute+0], ax ; low word lower part
[105]	1092	mov wptr cs:[INT13X_DAP_Absolute+2], bx ; high word lower part
	1093	mov wptr cs:[INT13X_DAP_Absolute+4], 0 ; low word upper part
	1094	mov wptr cs:[INT13X_DAP_Absolute+6], 0 ; high word upper part
[103]	1095
	1096	; Address of packet
[105]	1097	mov si, offset [INT13X_DAP] ; disk address packet
[103]	1098
	1099	; Do the extended write
[118]	1100	xor al, al ; no write verify
[103]	1101	mov ah, 43h ; write function
	1102	int 13h ; transfer to bios
[175]	1103	sti ; enable ints
[103]	1104
	1105	; Error occured
	1106	jc DriveIO_WriteSectorLBA_exit
	1107
	1108	; AH should also be zero
	1109	test ah, ah
	1110	stc
	1111	jnz DriveIO_WriteSectorLBA_exit
	1112
	1113	; Disk write succeeded, clear CF
	1114	clc
	1115
	1116	DriveIO_WriteSectorLBA_exit:
[118]	1117
[168]	1118	; Skip the removable drive check on success
	1119	jnc @F
	1120
	1121	; Here, CF=1 because of a failure.
	1122	; This could be from a removable drive that is set to read-only,
	1123	; in which case we want to fake success. What this boils down to
	1124	; is that CY must be set to !IsRemovable.
	1125	call DriveIO_CalcDiskInfoPointer ; Get DISKINFO pointer
	1126	mov dx, [bx+LocDISKINFO_I13X_Flags] ; Get INT13X flags
	1127	xor dl, 04h ; Invert 'removable' bit
	1128	and dl, 04h ; Mask it out
	1129	rcr dl, 3 ; Move it to CY
	1130
	1131	@@:
	1132
[118]	1133	; Pop all registers
	1134	pop es
	1135	pop ds
	1136	popa
	1137
[103]	1138	ret
	1139	DriveIO_WriteSectorLBA EndP
	1140
	1141
	1142
[115]	1143
	1144	;##############################################################################
	1145	;# The Master LVM sector is not necessarily located at the end of the BIOS
	1146	;# view of TRACK0. Its location depends on the OS/2 geometry active when the
	1147	;# disk was partitioned. For disks < 502MiB this will most likely be LBA sector
	1148	;# 62, but for disks >502MiB, extended OS/2 geometry was used and DANIS506
	1149	;# uses SPT=127 for disks < 1TiB while IBMS506 uses SPT=255.
	1150	;# When a huge disk < 1TiB was partitioned with IBMS506, thus using SPT=255,
	1151	;# and the driver was later changed to DANIS506, DANI uses SPT=255, eventhough
	1152	;# the disk < 1TiB. Whether it is DANI that is LVM aware or something else
	1153	;# (maybe LVM itself) that makes DANI use the correct geometry has yet to be
	1154	;# investigated.
	1155	;#
	1156	;# Related geometry issues are also present with USB sticks, which can get
	1157	;# assigned a geometry by OS/2, which can depend if the stick was partitioned
	1158	;# on foreign systems or not, or even OS/2 manufacturing a geometry that is not
	1159	;# the same as the BIOS reports to us here. In both cases, fixed disks and
	1160	;# removable disks, the geometry recorded in the BPB of a partition can also
	1161	;# influence the geometry that OS/2 assigns. This is the case when 'preparing'
	1162	;# disks for LVM use, in which case BPB values could be incorporated.
	1163	;#
	1164	;# What this all boils down to, is that the geometry reported by the BIOS is
	1165	;# of no practical use, especially not when taking BIOS USB MSD emulation into
	1166	;# account. These are among the reasons why AirBoot needs to use LBA addressing
	1167	;# when handling LVM stuff and why LBA use cannot be disabled in the SETUP
	1168	;# anymore.
	1169	;#
	1170	;# So, a Master LVM sector can be present on any sector from LBA 254 downwards
	1171	;# and the only way to locate the correct one is to scan all the way down and,
	1172	;# if one is found, do proper validation on its values, because it may also be
	1173	;# a 'phantom' LVM sector left over from previous partition layouts.
	1174	;# Most of such 'phantoms' can be filtered out by verifying the location of
	1175	;# the found sector against the OS/2 geometry it specifies itself, which means
	1176	;# it must be located at the LBA of the SPT-1 it specifies.
	1177	;##############################################################################
	1178	;# ACTION : Locates the Master LVM sector on the specified disk
	1179	;# ----------------------------------------------------------------------------
[124]	1180	;# EFFECTS : Leaves [Scratch] with last sector read or cleared
[115]	1181	;# ----------------------------------------------------------------------------
	1182	;# IN : DL - BIOS disk number of drive to search
	1183	;# ----------------------------------------------------------------------------
	1184	;# OUT : CF=1 - found
	1185	;# : BX:AX - LBA address of LVM sector if found, 0 otherwise
	1186	;##############################################################################
	1187	DriveIO_LocateMasterLVMSector Proc Near uses cx dx si di ds es
	1188
	1189	IFDEF AUX_DEBUG
[164]	1190	IF 0
[123]	1191	DBG_TEXT_OUT_AUX 'DriveIO_LocateMasterLVMSector:'
	1192	PUSHRF
[119]	1193	call DEBUG_DumpRegisters
[115]	1194	;~ call AuxIO_DumpSector
	1195	;~ call AuxIO_DumpParagraph
	1196	;~ call AuxIO_TeletypeNL
[123]	1197	POPRF
[115]	1198	ENDIF
	1199	ENDIF
	1200
	1201	; LBA address to start scanning down from
	1202	mov cx, 255
	1203
	1204	; Make sure ES==DS
	1205	push ds
	1206	pop es
	1207
[119]	1208	; Because JCXZ is used, LBA sector 0 is never loaded and checked.
	1209	; This is of course no problem since it is the MBR.
[115]	1210	DriveIO_LocateMasterLVMSector_next:
[124]	1211	mov si, offset [Scratch] ; Use scratch area to load sectors
	1212	call ClearSectorBuffer ; Clear the scratch area
[115]	1213	clc ; Indicate Master LVM sector not found
	1214	jcxz DriveIO_LocateMasterLVMSector_done
	1215
[124]	1216	; Read the LBA sector specified in CX
[118]	1217	mov ax, cx ; LBA low
	1218	xor bx, bx ; LBA high
[124]	1219	mov di, ds ; Segment of scratch buffer
	1220	mov si, offset [Scratch] ; Offset of scratch buffer
[115]	1221	call DriveIO_ReadSectorLBA ; Read the sector
[123]	1222	lahf ; Save CF
[115]	1223	dec cx ; Prepare LBA of next sector to read
	1224	sahf ; Restore CF
	1225	; No need to do any LVM sector validation when read error, read next
	1226	jc DriveIO_LocateMasterLVMSector_next
	1227
	1228	; See if the read sector has a valid signature and checksum
	1229	call LVM_ValidateSector
	1230
	1231	; NC indicates invalid or none-LVM sector, read next
	1232	jnc DriveIO_LocateMasterLVMSector_next
	1233
	1234	; We have found a valid LVM sector !
	1235	; So it contains the OS/2 geometry for the disk.
	1236	; That means this LVM sector itself must be located on the last sector
	1237	; of the SPT value its OS/2 geometery specifies, which, in LBA terms
	1238	; is LVM SPT-1 -- let's check that...
[124]	1239	mov bx, offset [Scratch] ; Offset of the loaded LVM sector
[115]	1240	mov al, [bx+LocLVM_Secs] ; Get the LVM SPT value (<=255)
	1241	dec al ; Adjust to LVM LBA
	1242	mov ah, cl ; Get next LVM LBA to search
	1243	inc ah ; This one was found here
	1244	cmp al, ah ; If same, LVM LBA location OK
	1245	jne DriveIO_LocateMasterLVMSector_next
	1246
	1247	; The LVM sector we found is at the location it should be on disk,
	1248	; so it's almost 99% sure this is the correct one.
	1249	; Now we should compare the start and sizes of the partitions in the
	1250	; MBR with the partitions specified in this LVM record.
	1251	; We'll implement that later after some more research.
	1252	; For now we assume this is the correct Master LVM sector for the disk.
	1253	inc cx ; CX was prepared to read next, correct that
[118]	1254	stc ; Indicate we have found the Master LVM sector
[115]	1255
	1256	DriveIO_LocateMasterLVMSector_done:
	1257	mov bx, 0 ; A Master LVM sector always has high LBA=0
	1258	mov ax, cx ; Low LBA of Master LVM sector
	1259
	1260	; We leave it up to the caller to store the value in a proper place
	1261	ret
	1262	DriveIO_LocateMasterLVMSector EndP
	1263
	1264
	1265
[51]	1266	;
	1267	; ############################################################
	1268	; # Check for a valid MBR-sector to be written to disk #
	1269	; ############################################################
	1270	;
	1271	; In
	1272	; --
	1273	; DL = Physical Disk
	1274	; BX:CX = LBA sector
	1275	; DI:SI = Source buffer
	1276	;
	1277	; Out
	1278	; ---
	1279	; CY = 1 if invalid MBR in source buffer, 0 if valid
	1280	;
	1281	; This routine is called when DriveIO_SaveSector attempts to write to the MBR.
	1282	; It checks if the sector to be written has some sensible values in certain
	1283	; places. In fact, if the sector is written to the boot-disk, the AiR-BOOT
	1284	; signature should be present and the partition table should be the same
	1285	; as the one at the start of the AiR-BOOT code in memory, except maybe for the
	1286	; active flags.
	1287	; For other disks, only the active flags are checked to be 00h or 80h and
	1288	; the AA55h MBR signature.
	1289	;
	1290	DriveIO_ProtectMBR Proc Near
	1291	pusha ; Push all registers
	1292	push es ; Push ES because we need it for string instructions
	1293	push cs ; Make ES point...
	1294	pop es ; to CS
[32]	1295
[51]	1296	; Save the pointer to the sector to write in BX
	1297	mov bx,si
	1298
	1299	;
	1300	; If the sector to be written is not the boot-disk, then skip
	1301	; checking the AiR-BOOT MBR.
	1302	;
[78]	1303	cmp dl, [BIOS_BootDisk]
	1304	jne DriveIO_ProtectMBR_is_not_bootdisk
[51]	1305
	1306	;
	1307	; The boot-disk is accessed so the sector to be written must be
	1308	; the AiR-BOOT MBR. This is the same as the first 512 bytes
	1309	; relocated to 8000:0000 and this the start of the AB-code.
	1310	;
	1311	mov si,bx ; Get pointer to sector to write
	1312	xor di,di ; Point DI to start of AB-code (MBR)
	1313	mov cx, offset [MBR_PartTable] ; Bytes upto P-table must be same
	1314	cld ; Compare upwards
	1315	repe cmpsb ; Compare upto P-table
	1316
	1317	; If not the same this is not the an AiR-BOOT boot-disk MBR !
	1318	jne DriveIO_ProtectMBR_not_valid_MBR ; SEVERE ERROR !
	1319
	1320	; Continue with signature check
	1321	jmp DriveIO_ProtectMBR_check_signature
	1322
	1323
	1324	;
	1325	; The disk is not the boot-disk so we don't know what kind of MBR is on it.
	1326	; Some sanity checks should be here.
	1327	;
	1328	DriveIO_ProtectMBR_is_not_bootdisk:
	1329
	1330	;
	1331	; sanity checks...
	1332	;
	1333
	1334	; Continue with signature check
	1335	jmp DriveIO_ProtectMBR_check_signature
	1336
	1337
	1338	DriveIO_ProtectMBR_check_signature:
	1339	; See if the sector to write contains a valid signature
	1340	mov si,bx ; Get pointer to sector to write
	1341	mov di, offset [MBR_Sig] ; Offset to MBR signature
	1342	add si,di ; Make SI point to it in sec to write
	1343	lodsw ; Load it
	1344	cmp ax,0aa55h ; See if it is valid
	1345
	1346	; If no signature this cannot be a valid MBR !
	1347	jne DriveIO_ProtectMBR_not_valid_MBR ; SEVERE ERROR !
	1348
	1349
	1350	;
	1351	; The sector to be written seems to be valid.
	1352	; Set CY=0 to indicate a valid MBR.
	1353	;
	1354	DriveIO_ProtectMBR_is_valid_MBR:
	1355	clc
	1356	jmp DriveIO_ProtectMBR_end
	1357
	1358	;
	1359	; Something is terribly wrong; a non-MBR sector seems about to be written.
	1360	; Set CY=1 and let the calling code handle this situation.
	1361	;
	1362	DriveIO_ProtectMBR_not_valid_MBR:
	1363	stc
	1364	jmp DriveIO_ProtectMBR_end
	1365
	1366	;
	1367	; Return to the caller with no registers modyfied except FLAGS.
	1368	;
	1369	DriveIO_ProtectMBR_end:
	1370	pop es
	1371	popa
	1372	ret
	1373	DriveIO_ProtectMBR Endp
	1374
	1375
	1376
[30]	1377	; #########################################################################
[51]	1378	; Routine: Checks if the MBR is addressed by either CHS or LBA
	1379	; #########################################################################
	1380	; Calling : bx:ax - Absolute sector
	1381	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
	1382	; Returns : ZF=1 if MBR is addressed, else ZF=0
	1383	; Preserve: all registers
	1384	; #########################################################################
	1385	DriveIO_MBR_Addressed Proc
	1386	push ax
	1387	push bx
	1388
	1389	or bx,ax ; Results in 0 in BX if MBR is addressed by LBA
	1390	jz DriveIO_MBR_Addressed_done
	1391
	1392	mov ax,cx ; Results in 1 in AX if CYL 0, SEC 1 is addressed
	1393	add al,dh ; Results in 1 in AX if HEAD 0 is addressed
	1394	dec ax ; Results in 0 in AX if MBR is addressed by CHS
	1395
	1396	DriveIO_MBR_Addressed_done:
	1397	pop bx
	1398	pop ax
	1399	ret
	1400	DriveIO_MBR_Addressed EndP
	1401
	1402
	1403
	1404
	1405	; #########################################################################
[30]	1406	; Routine: Writes DS:SI to a specified sector
	1407	; #########################################################################
	1408	; Calling : bx:ax - Absolute sector
	1409	; cx:dx - Cylinder/Sector, Side/Drive (hi/lo-byte)
	1410	; ds:si - Source-Adress
	1411	; Returns : none
	1412	; Preserve: all registers
	1413	; #########################################################################
[51]	1414	DriveIO_SaveSector Proc Near Uses ax bx cx dx ds si es di
[50]	1415
[111]	1416	IFDEF AUX_DEBUG
	1417	IF 0
[123]	1418	DBG_TEXT_OUT_AUX 'DriveIO_SaveSector:'
	1419	PUSHRF
[164]	1420	call DEBUG_DumpRegisters
[111]	1421	;~ call AuxIO_DumpParagraph
	1422	;~ call AuxIO_TeletypeNL
[123]	1423	POPRF
[111]	1424	ENDIF
	1425	ENDIF
[51]	1426
[117]	1427
	1428	;!
	1429	;! DEBUG_BLOCK
	1430	;! Force write to LBA0 to test interception routine.
	1431	;! Do NOT enable unless you are debugging, will overwrite MBR !
	1432	;!
	1433	IFDEF AUX_DEBUG
	1434	IF 0
	1435	pushf
	1436	pusha
[51]	1437	xor ax,ax
	1438	xor bx,bx
	1439	xor cx,cx
	1440	inc cx
	1441	xor dh,dh
[117]	1442	popa
	1443	popf
[51]	1444	ENDIF
[117]	1445	ENDIF
[51]	1446
	1447	;
	1448	; Check if the MBR is the destination for the write.
	1449	; ZF=1 if so.
	1450	;
	1451	call DriveIO_MBR_Addressed
	1452	jnz DriveIO_SaveSector_continue_write
	1453
	1454
	1455	; MBR is addressed, check the sector that is requested to be written.
	1456	; For the bootdisk it should contain the AiR-BOOT signature, valid
	1457	; partition-table entries and the AA55h signature.
	1458	; If not, something is terribly wrong in some piece of the AB code.
	1459	; For any other disk (80h+) at least a valid partition table should
	1460	; be present together with the AA55h signature.
	1461	call DriveIO_ProtectMBR
	1462	jnc DriveIO_SaveSector_continue_write
	1463
	1464
	1465	;
	1466	; WE HAVE A SEVERE ERROR CONDITION !
	1467	; SOME AB CODE TRIES TO WRITE A NON-MBR TO THE DISK !
	1468	; ASK THE USER TO REPORT THIS !
	1469	; HALT THE SYSTEM !
	1470	;
	1471
	1472	; Show error-box
	1473	mov cx, 0C04h
	1474	mov si, offset NonMBRwrite
	1475	call SETUP_ShowErrorBox
	1476	mov cx, 0C04h
	1477	mov si, offset NonMBRwrite_rep
	1478	call SETUP_ShowErrorBox
	1479
	1480
[117]	1481	IFDEF AUX_DEBUG
	1482	IF 0
	1483	pushf
	1484	pusha
	1485	mov si, offset [NonMBRwrite]
[51]	1486	call AuxIO_TeletypeNL
	1487	call AuxIO_Print
	1488	call AuxIO_TeletypeNL
[117]	1489	popa
	1490	popf
[51]	1491	ENDIF
[117]	1492	ENDIF
[51]	1493
	1494	; Show popup and halt the system.
	1495	jmp HaltSystem
	1496
	1497
	1498
	1499	;
	1500	; Continue the write if not MBR sector or MBR to write is validated.
	1501	;
	1502	DriveIO_SaveSector_continue_write:
[46]	1503	test byte ptr cs:[CurIO_UseExtension], 1
[43]	1504	jz DIOSS_UseNormal
	1505	; Are we forced do use LBA via Setting?
[54]	1506	; Always use INT13X on v1.0.8+.
[50]	1507	;~ test byte ptr cs:[CFG_ForceLBAUsage], 1
	1508	;~ jnz DIOSS_UseExtension
	1509	jmp DIOSS_UseExtension
[43]	1510	; Is the drive not a harddrive?
	1511	cmp dl, 80h
	1512	jb DIOSS_UseNormal
	1513	; Upper 8 bits of LBA-address set? -> Use LBA (maximum boundary is FB0400h)
	1514	or bh, bh
	1515	jnz DIOSS_UseExtension
	1516	; Compare Switch-Table value to bit 16-23 of LBA-address
	1517	mov di, dx
	1518	and di, 007Fh
	1519	cmp bptr cs:[LBASwitchTable+di], bl
	1520	jbe DIOSS_UseExtension
[110]	1521
[43]	1522	DIOSS_UseNormal:
[111]	1523
	1524	IFDEF AUX_DEBUG
	1525	IF 0
[123]	1526	DBG_TEXT_OUT_AUX 'DriveIO_WriteSectorCHS:'
	1527	PUSHRF
[111]	1528	call DEBUG_DumpRegisters
	1529	call AuxIO_DumpParagraph
	1530	call AuxIO_TeletypeNL
[123]	1531	POPRF
[111]	1532	ENDIF
	1533	ENDIF
	1534
	1535	mov di, 3 ; retry count
[43]	1536	DIOSS_ErrorLoop:
	1537	push ds
	1538	pop es
	1539	mov bx, si ; ES:BX - Destination
	1540	mov ax, 0301h ; Function 3 - Write Sector
	1541	int 13h
[175]	1542	sti ; Enable ints
[43]	1543	jnc DIOSS_Success
[111]	1544	dec di ; decrement retry count
[43]	1545	jnz DIOSS_ErrorLoop
	1546	call MBR_SaveError
[8]	1547
[43]	1548	DIOSS_UseExtension:
[8]	1549
[110]	1550	mov di, ds ; segment for transfer address
	1551	call DriveIO_WriteSectorLBA ; extended write
	1552	jc MBR_SaveError ; halt on error
	1553
	1554	;~ push cx
	1555	;~ mov cs:[INT13X_DAP_NumBlocks], 1 ; Copy ONE sector
	1556	;~ mov wptr cs:[INT13X_DAP_Transfer+0], si
	1557	;~ mov cx, ds
	1558	;~ mov wptr cs:[INT13X_DAP_Transfer+2], cx ; Fill out Transfer Adress
	1559	;~ mov wptr cs:[INT13X_DAP_Absolute+0], ax
	1560	;~ mov wptr cs:[INT13X_DAP_Absolute+2], bx ; Fill out Absolute Sector
	1561	;~ push cs
	1562	;~ pop ds
	1563	;~ mov si, offset [INT13X_DAP]
	1564	;~ mov ax, 4300h ; Extended Write (No Verify)
	1565	;~ int 13h
	1566	;~ pop cx
	1567	;~ jnc DIOSS_Success
	1568	;~ call MBR_SaveError
	1569
[43]	1570	DIOSS_Success:
	1571	ret
[8]	1572	DriveIO_SaveSector EndP
[30]	1573
	1574
	1575
[136]	1576
	1577	;##############################################################################
	1578	;# When a disk has a Master LVM sector, it means it has been prepared for use
	1579	;# by OS/2 and contains important information about how OS/2 views its geometry
	1580	;# and other disk related properties. This function assumes the LBA address
	1581	;# of the Master LVM sector has already been located and simply loads the
	1582	;# sector into [LVMSector].
	1583	;#
	1584	;# Note that because this is an operation similar to the regular loading of
	1585	;# sectors, the disk I/O semantics are used here. This means CF=0 when an LVM
	1586	;# sector is successfully loaded and CF=1 otherwise.
	1587	;##############################################################################
	1588	;# ACTION : Loads the Master LVM sector if one exists
	1589	;# ----------------------------------------------------------------------------
	1590	;# EFFECTS : Modifies DAP structure and [LVMSector]
	1591	;# ----------------------------------------------------------------------------
	1592	;# IN : DL - BIOS disk number (80h,81h,etc)
	1593	;# ----------------------------------------------------------------------------
	1594	;# OUT : CF=0 - Valid Master LVM sector found and loaded
	1595	;##############################################################################
[43]	1596	DriveIO_LoadMasterLVMSector Proc Near
[111]	1597
	1598	IFDEF AUX_DEBUG
	1599	IF 0
[123]	1600	DBG_TEXT_OUT_AUX 'DriveIO_LoadMasterLVMSector:'
	1601	PUSHRF
[111]	1602	;~ call DEBUG_DumpRegisters
	1603	;~ call AuxIO_DumpParagraph
	1604	;~ call AuxIO_TeletypeNL
[123]	1605	POPRF
[111]	1606	ENDIF
	1607	ENDIF
[30]	1608
[136]	1609	; Save all registers
[111]	1610	pusha
[30]	1611
[136]	1612	; Check if BIOS disk number is valid
	1613	call DriveIO_IsValidHarddisk
	1614	jc DriveIO_LoadMasterLVMSector_error
[32]	1615
[136]	1616	; Calculate the entry in the DISKINFO array for this disk
	1617	call DriveIO_CalcDiskInfoPointer
[32]	1618
[136]	1619	; Save the entry for later recalls
	1620	mov bp, bx
[32]	1621
[136]	1622	; Get the LBA address of the Master LVM sector
	1623	mov ax, [bx+LocDISKINFO_LVM_MasterLBA+00h]
	1624	mov bx, [bx+LocDISKINFO_LVM_MasterLBA+02h]
[32]	1625
[136]	1626	; LBA of Master LVM sector cannot be 0, so none was found during
	1627	; the gathering of disk information.
	1628	mov cx, ax
	1629	or cx, bx
	1630	jz DriveIO_LoadMasterLVMSector_error
[32]	1631
[136]	1632	; Load it into [LVMSector]
	1633	mov di, ds
	1634	mov si, offset [LVMSector]
	1635	call DriveIO_ReadSectorLBA
	1636	jc DriveIO_LoadMasterLVMSector_error
[30]	1637
[136]	1638	; Validate the Master LVM sector
[100]	1639	call LVM_ValidateSector
[30]	1640
[136]	1641	; Complement success indicator to conform to semantics of this function
	1642	cmc
[117]	1643
[136]	1644	; Master LVM sector was valid and is now loaded in [LVMSector]
	1645	jnc DriveIO_LoadMasterLVMSector_ret
[117]	1646
[136]	1647	DriveIO_LoadMasterLVMSector_error:
[30]	1648
[136]	1649	; Clear the sector buffer for safety reasons
	1650	mov si, offset [LVMSector]
	1651	call ClearSectorBuffer
[30]	1652
[136]	1653	; Indicate no Master LVM sector loaded
	1654	stc
[114]	1655
[136]	1656	DriveIO_LoadMasterLVMSector_ret:
[32]	1657
[136]	1658	; Restore all registers
	1659	popa
[32]	1660
	1661	ret
[30]	1662	DriveIO_LoadMasterLVMSector Endp
	1663
	1664
	1665
	1666
[137]	1667	;##############################################################################
	1668	;# There is much information to know about the connected disks.
	1669	;# We also want this information clustered per disk and available before
	1670	;# further disk and partition scanning takes place.
	1671	;# This function gathers such information like INT13, INT13X, MBR, LVM, more.
	1672	;# Especially important is the LVM information, because that contains the
	1673	;# geometry OS/2 uses to access the disk. Other important information is the
	1674	;# presence of valid MBRs, logical partitions and whatnot.
	1675	;# This function gathers such information and stores it in a DISKINFO structure
	1676	;# for which an instance exists for every disk found.
	1677	;##############################################################################
	1678	;# ACTION : Gather disk information and store this in the BSS
	1679	;# ----------------------------------------------------------------------------
	1680	;# EFFECTS : Modifies DAP structure and the buffers it uses, fills DISKINFO[n]
	1681	;# ----------------------------------------------------------------------------
	1682	;# IN : DL - BIOS disk number (80h,81h,etc)
	1683	;# ----------------------------------------------------------------------------
	1684	;# OUT : CF=1 - failure
	1685	;##############################################################################
	1686	DriveIO_GatherDiskInfo Proc Near
[136]	1687
[137]	1688	IFDEF AUX_DEBUG
[164]	1689	IF 0
[137]	1690	DBG_TEXT_OUT_AUX 'DriveIO_GatherDiskInfo:'
	1691	PUSHRF
	1692	call DEBUG_DumpRegisters
	1693	;~ call AuxIO_DumpParagraph
	1694	;~ call AuxIO_TeletypeNL
	1695	POPRF
	1696	ENDIF
	1697	ENDIF
[30]	1698
[137]	1699	; Push all registers we use
	1700	pusha
	1701	push ds
	1702	push es
[30]	1703
[137]	1704	; Make sure ES=DS
	1705	push ds
	1706	pop es
[30]	1707
[137]	1708	; Check if BIOS disk number is valid
	1709	call DriveIO_IsValidHarddisk
	1710	jc DriveIO_GatherDiskInfo_error
[30]	1711
[137]	1712	; Calculate the entry in the DISKINFO array for this disk
	1713	call DriveIO_CalcDiskInfoPointer
[30]	1714
[137]	1715	; Save the entry for later recalls
	1716	mov bp, bx
[30]	1717
[137]	1718	; Store the BIOS disk number in the structure
	1719	mov [bx+LocDISKINFO_DiskNum], dl
[30]	1720
[137]	1721	; ------------------------------------------------------------------- [ INT13 ]
[30]	1722
[137]	1723	; Get BIOS Disk Parameters (legacy method)
	1724	mov ah, 08h ; Get Disk Parameters
	1725	int 13h ; Call BIOS
[175]	1726	sti ; Enable ints
[30]	1727
[137]	1728	; CF=1 or AH!=0 indicates error
	1729	jc DriveIO_GatherDiskInfo_error
	1730	test ah, ah
	1731	jnz DriveIO_GatherDiskInfo_error
[30]	1732
[137]	1733	; Recall DISKINFO entry
	1734	mov bx, bp
[30]	1735
[137]	1736	; Store SPT (WORD)
	1737	xor ah, ah ; Zero extend SPT to 16 bits
	1738	mov al, cl ; Hi 2 bits max cyl and max sec
	1739	and al, 3fh ; Mask max sec (1-based)
	1740	mov [bx+LocDISKINFO_I13_Secs], ax ; Store SPT
[30]	1741
[137]	1742	; Store HEADS (WORD)
	1743	xor dl, dl ; Zero extend HEADS to 16 bits
	1744	xchg dl, dh ; Get max head (0-based)
	1745	inc dx ; Head count
	1746	mov [bx+LocDISKINFO_I13_Heads], dx ; Store HEADS
[30]	1747
[137]	1748	; Store CYLS (WORD)
	1749	shr cl, 6 ; Hi 2 bits of max cyl to 1:0
	1750	xchg cl, ch ; Max cyl (0-based)
	1751	inc cx ; Cyl count
	1752	mov [bx+LocDISKINFO_I13_Cyls], cx ; Store CYLS
[30]	1753
[137]	1754	; Recall BIOS disk number
	1755	mov dl, [bx+LocDISKINFO_DiskNum]
[30]	1756
[137]	1757	; ------------------------------------------------------------------ [ INT13X ]
[30]	1758
[137]	1759	; Get BIOS Disk Parameters (extended method)
	1760	mov si, offset [Scratch] ; Buffer to return disk info
	1761	mov ax, 80h ; Size of buffer
	1762	mov [si], ax ; Store it in first word
	1763	mov ah, 48h ; Get Extended Disk Parameters
	1764	int 13h ; Call BIOS
[175]	1765	sti ; Enable ints
[30]	1766
[137]	1767	; CF=1 or AH!=0 indicates error
	1768	jc DriveIO_GatherDiskInfo_error
	1769	test ah, ah
	1770	jnz DriveIO_GatherDiskInfo_error
[30]	1771
[137]	1772	; Store flags (WORD)
	1773	cld ; Direction up
	1774	lodsw ; Buffersize, discard
	1775	lodsw ; Flags (CHS valid etc)
	1776	mov [bx+LocDISKINFO_I13X_Flags], ax ; Store them
[111]	1777
[137]	1778	; Store CYLS (DWORD)
	1779	lodsw ; Cyl count low
	1780	mov [bx+LocDISKINFO_I13X_Cyls+00h], ax ; Store CYLS low
	1781	lodsw ; Cyl count high
	1782	mov [bx+LocDISKINFO_I13X_Cyls+02h], ax ; Store CYLS high
[111]	1783
[137]	1784	; Store HEADS (DWORD)
	1785	lodsw ; Head count low
	1786	mov [bx+LocDISKINFO_I13X_Heads+00h], ax ; Store HEADS low
	1787	lodsw ; Head count high
	1788	mov [bx+LocDISKINFO_I13X_Heads+02h], ax ; Store HEADS high
[30]	1789
[137]	1790	; Store SPT (DWORD)
	1791	lodsw ; Secs per track low
	1792	mov [bx+LocDISKINFO_I13X_Secs+00h], ax ; Store SPT low
	1793	lodsw ; Secs per track high
	1794	mov [bx+LocDISKINFO_I13X_Secs+02h], ax ; Store SPT high
[30]	1795
[137]	1796	; Store total LBA sectors (QWORD)
	1797	lea di, [bx+LocDISKINFO_I13X_SecsLBA]
	1798	mov cx, 4
	1799	rep movsw
[30]	1800
[137]	1801	; Store sector size (WORD)
	1802	lodsw
	1803	mov [bx+LocDISKINFO_I13X_SecSize], ax
[30]	1804
[137]	1805	; Store bus name (4 bytes, space padded, v3.0+)
	1806	lea si, [Scratch+24h]
	1807	lea di, [bx+LocDISKINFO_I13X_HostBus]
	1808	movsw
	1809	movsw
[30]	1810
[137]	1811	; Store interface name (8 bytes, space padded, v3.0+)
	1812	lea di, [bx+LocDISKINFO_I13X_Interface]
	1813	mov cx, 4
	1814	rep movsw
[30]	1815
[137]	1816	; Should gather some more INT13X info here,
	1817	; like maybe Advanced Format stuff or so.
	1818	; We'll investigate that at a later time.
[30]	1819
[137]	1820	; --------------------------------------------------------------------- [ MBR ]
[30]	1821
[137]	1822	; Load the MBR
	1823	mov si, offset [TmpSector]
	1824	call DriveIO_LoadMBR
[30]	1825
[137]	1826	; Store MBR flags (valid sig, partitions present, airboot installed)
	1827	mov [bx+LocDISKINFO_MbrFlags], al
[30]	1828
[137]	1829	; Recall BIOS disk number
	1830	mov dl, [bx+LocDISKINFO_DiskNum]
[30]	1831
[137]	1832	; --------------------------------------------------------------------- [ LVM ]
[30]	1833
[137]	1834	; Locate the Master LVM sector, if any
	1835	call DriveIO_LocateMasterLVMSector
[30]	1836
[137]	1837	; Save Master LVM sector LBA high
	1838	mov cx, bx
[30]	1839
[137]	1840	; Recall DISKINFO entry
	1841	mov bx, bp
[30]	1842
[137]	1843	; Store Master LVM sector LBA
	1844	mov [bx+LocDISKINFO_LVM_MasterLBA+00h], ax
	1845	mov [bx+LocDISKINFO_LVM_MasterLBA+02h], cx
[30]	1846
[137]	1847	; No Master LVM sector found, so skip storing LVM info for this disk
	1848	jnc DriveIO_GatherDiskInfo_no_master_lvm
[30]	1849
[137]	1850	; Load the Master LVM sector into [LVMSector]
	1851	call DriveIO_LoadMasterLVMSector
[30]	1852
[137]	1853	; No valid Master LVM sector, so skip storing LVM info for this disk
	1854	jc DriveIO_GatherDiskInfo_no_master_lvm
[30]	1855
[137]	1856	; A valid Master LVM sector has been loaded into [LVMSector]
	1857	mov si, offset [LVMSector]
[30]	1858
[137]	1859	; Get the number of sectors per track (OS/2 geometry)
	1860	mov ax, [si+LocLVM_Secs+00h]
	1861	mov cx, [si+LocLVM_Secs+02h]
[30]	1862
[137]	1863	; Store it
	1864	mov [bx+LocDISKINFO_LVM_Secs+00h], ax
	1865	mov [bx+LocDISKINFO_LVM_Secs+02h], cx
[30]	1866
[137]	1867	; Get the number of heads (OS/2 geometry)
	1868	mov ax, [si+LocLVM_Heads+00h]
	1869	mov cx, [si+LocLVM_Heads+02h]
[30]	1870
[137]	1871	; Store it
	1872	mov [bx+LocDISKINFO_LVM_Heads+00h], ax
	1873	mov [bx+LocDISKINFO_LVM_Heads+02h], cx
[30]	1874
[137]	1875	; Should gather some more LVM info here,
	1876	; like OS/2 extended geometry and other flags.
	1877	; We'll implement that at a later time.
[30]	1878
[137]	1879	DriveIO_GatherDiskInfo_no_master_lvm:
[30]	1880
[137]	1881	; When no Master LVM sector was found,
	1882	; the LVM info in the DISKINFO structure for the disk
	1883	; will be ZERO because the area was cleared in PRECRAP.
[30]	1884
[137]	1885	; Indicate success
	1886	clc
	1887
	1888	jmp DriveIO_GatherDiskInfo_ret
	1889
	1890	DriveIO_GatherDiskInfo_error:
	1891	stc
[43]	1892	DriveIO_GatherDiskInfo_ret:
[137]	1893
	1894
	1895	IFDEF AUX_DEBUG
[164]	1896	IF 0
[137]	1897	DBG_TEXT_OUT_AUX '[DISKINFO]'
	1898	PUSHRF
	1899	call DEBUG_DumpRegisters
	1900	;~ call AuxIO_DumpParagraph
	1901	;~ call AuxIO_TeletypeNL
	1902	mov si, bp
	1903	mov cx, 4
	1904	@@:
	1905	call AuxIO_DumpParagraph
	1906	call AuxIO_TeletypeNL
	1907	add si, 16
	1908	loop @B
	1909	mov si, offset [Scratch]
	1910	mov cx, 4
	1911	@@:
	1912	call AuxIO_DumpParagraph
	1913	call AuxIO_TeletypeNL
	1914	add si, 16
	1915	loop @B
	1916	mov si, offset [LVMSector]
	1917	mov cx, 7
	1918	@@:
	1919	call AuxIO_DumpParagraph
	1920	call AuxIO_TeletypeNL
	1921	add si, 16
	1922	loop @B
	1923	POPRF
	1924	ENDIF
	1925	ENDIF
	1926
	1927	; Restore registers
[43]	1928	pop es
[137]	1929	pop ds
	1930	popa
[30]	1931
[43]	1932	ret
[30]	1933	DriveIO_GatherDiskInfo EndP
	1934
[130]	1935	;------------------------------------------------------------------------------
[143]	1936	; Scan all disks to gather information
	1937	;------------------------------------------------------------------------------
	1938	; IN : None
	1939	; OUT : CF=1 - some failure occured
	1940	; : ZF=1 - no harddisks
	1941	; NOTE : This does the preliminary gathering of disk information
	1942	;------------------------------------------------------------------------------
	1943	DriveIO_ScanDisks Proc Near
	1944
	1945	IFDEF AUX_DEBUG
[164]	1946	IF 0
[143]	1947	DBG_TEXT_OUT_AUX 'DriveIO_ScanDisks:'
	1948	PUSHRF
	1949	call DEBUG_DumpRegisters
	1950	;~ call AuxIO_DumpParagraph
	1951	;~ call AuxIO_TeletypeNL
	1952	POPRF
	1953	ENDIF
	1954	ENDIF
	1955
	1956	; Save all registers
	1957	pusha
	1958
	1959	; Get number of disks in DH
	1960	call DriveIO_GetHardDriveCount
	1961
	1962	; Check if there are any disks to scan
	1963	xor cx, cx ; Prepare 16-bit counter
	1964	mov cl, dh ; Number of disks now in CX
	1965	jcxz DriveIO_ScanDisks_end ; Quit if no disks
	1966
	1967	; Scan disks from 80h upward
	1968	mov dl, 80h ; BIOS number of first disk
	1969	DriveIO_ScanDisks_next:
	1970	call DriveIO_GatherDiskInfo ; Gather info for this disk
	1971	jc DriveIO_ScanDisks_end ; Quit if some error occured
	1972	inc dl ; Advance to next disk
	1973	loop DriveIO_ScanDisks_next ; Scan next disk if there is one
	1974	test dl, dl ; Set ZF=0
	1975	clc ; Indicate success
	1976
	1977	DriveIO_ScanDisks_end:
	1978	; Restore all registers
	1979	popa
	1980
	1981	ret
	1982	DriveIO_ScanDisks EndP
	1983
	1984	;------------------------------------------------------------------------------
[130]	1985	; Calculate pointer to entry in DISKINFO structure
	1986	;------------------------------------------------------------------------------
	1987	; IN : DL BIOS disk number (80h etc)
	1988	; OUT : BX Pointer to entry
	1989	; NOTE : BIOS disk number must be valid
	1990	;------------------------------------------------------------------------------
	1991	DriveIO_CalcDiskInfoPointer Proc Near
	1992	xchg bx, ax ; AX is used for calculation
	1993	mov al, DISKINFO_Size ; Size of DISKINFO structure
	1994	mov ah, dl ; BIOS disk number
	1995	sub ah, 80h ; Now 0-based index
	1996	mul ah ; Now offset into DISKINFO array
	1997	add ax, offset [DiskInformation] ; Base of DISKINFO array
	1998	xchg bx, ax ; BX now points to entry for disk
	1999	ret
	2000	DriveIO_CalcDiskInfoPointer EndP
[30]	2001
[120]	2002	;------------------------------------------------------------------------------
	2003	; Check if the BIOS disk number in DL is a harddisk and in range
	2004	;------------------------------------------------------------------------------
	2005	; IN : DL BIOS disk number (80h etc)
	2006	; OUT : CF=1 if invalid disk number or out of range
	2007	; NOTE : Only modifies flags
	2008	;------------------------------------------------------------------------------
	2009	DriveIO_IsValidHarddisk Proc Near Uses dx
	2010	cmp dl, 80h ; BIOS disk number must be at least 80h
	2011	jb @F ; Not a harddisk, exit with CY
	2012	mov dh, dl ; Save to do compare
	2013	sub dh, 80h ; Now 0 based disk number
	2014	inc dh ; Now 1 based disk number
	2015	cmp [TotalHarddiscs], dh ; Out of range, exit with CY
	2016	@@: ret
	2017	DriveIO_IsValidHarddisk EndP
[30]	2018
[120]	2019
[30]	2020	; Values for sectors per track table corresponding to DriveIO_IsHugeDrive return value.
[137]	2021	;~ secs_per_track_table db 63,127,255,255,255,255
[30]	2022
[123]	2023	;~ db_lmlvm db 'Load Master LVM -- disk: ',0

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source: trunk/bootcode/regular/driveio.asm

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