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source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 350

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Last change on this file since 350 was 346, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

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[99]	1	; Project name : XTIDE Universal BIOS
[3]	2	; Description : Functions for creating Disk Parameter Table.
	3
	4	; Section containing code
	5	SECTION .text
	6
	7	;--------------------------------------------------------------------
	8	; Creates new Disk Parameter Table for detected hard disk.
	9	; Drive is then fully accessible using any BIOS function.
	10	;
	11	; CreateDPT_FromAtaInformation
	12	; Parameters:
	13	; BH: Drive Select byte for Drive and Head Register
	14	; ES:SI: Ptr to 512-byte ATA information read from the drive
	15	; CS:BP: Ptr to IDEVARS for the controller
	16	; DS: RAMVARS segment
	17	; ES: BDA Segment
	18	; Returns:
	19	; DL: Drive number for new drive
[294]	20	; DS:DI: Ptr to Disk Parameter Table (if successful)
[3]	21	; CF: Cleared if DPT created successfully
	22	; Set if any error
	23	; Corrupts registers:
[99]	24	; AX, BX, CX, DH
[3]	25	;--------------------------------------------------------------------
	26	CreateDPT_FromAtaInformation:
[150]	27	call FindDPT_ForNewDriveToDSDI
[99]	28	; Fall to .InitializeDPT
[3]	29
	30	;--------------------------------------------------------------------
[99]	31	; .InitializeDPT
[3]	32	; Parameters:
	33	; BH: Drive Select byte for Drive and Head Register
	34	; DS:DI: Ptr to Disk Parameter Table
	35	; CS:BP: Ptr to IDEVARS for the controller
	36	; Returns:
[150]	37	; Nothing
[3]	38	; Corrupts registers:
[150]	39	; AX
[3]	40	;--------------------------------------------------------------------
[99]	41	.InitializeDPT:
[150]	42	mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
	43	; Fall to .StoreDriveSelectAndDriveControlByte
[3]	44
	45	;--------------------------------------------------------------------
[150]	46	; .StoreDriveSelectAndDriveControlByte
[3]	47	; Parameters:
	48	; BH: Drive Select byte for Drive and Head Register
	49	; DS:DI: Ptr to Disk Parameter Table
	50	; ES:SI: Ptr to 512-byte ATA information read from the drive
	51	; CS:BP: Ptr to IDEVARS for the controller
	52	; Returns:
[99]	53	; Nothing
[3]	54	; Corrupts registers:
	55	; AX
	56	;--------------------------------------------------------------------
[150]	57	.StoreDriveSelectAndDriveControlByte:
	58	mov al, bh
	59	and ax, BYTE FLG_DRVNHEAD_DRV ; AL now has Master/Slave bit
	60	cmp [cs:bp+IDEVARS.bIRQ], ah ; Interrupts enabled?
	61	jz SHORT .StoreFlags ; If not, do not set interrupt flag
[158]	62	or al, FLGL_DPT_ENABLE_IRQ
[150]	63	.StoreFlags:
	64	mov [di+DPT.wFlags], ax
[173]	65	; Fall to .StoreAddressing
[3]	66
	67	;--------------------------------------------------------------------
[173]	68	; .StoreAddressing
[3]	69	; Parameters:
	70	; DS:DI: Ptr to Disk Parameter Table
	71	; ES:SI: Ptr to 512-byte ATA information read from the drive
	72	; CS:BP: Ptr to IDEVARS for the controller
	73	; Returns:
[227]	74	; Nothing
[3]	75	; Corrupts registers:
[227]	76	; AX, BX, CX, DX
[3]	77	;--------------------------------------------------------------------
[173]	78	.StoreAddressing:
	79	; Check if CHS defined in ROMVARS
[193]	80	call AccessDPT_GetPointerToDRVPARAMStoCSBX
	81	test byte [cs:bx+DRVPARAMS.wFlags], FLG_DRVPARAMS_USERCHS ; User specified CHS?
[227]	82	jnz SHORT .StoreUserDefinedPCHS
[173]	83
	84	; Check if LBA supported
[169]	85	call AtaID_GetPCHStoAXBLBHfromAtaInfoInESSI
[173]	86	test BYTE [es:si+ATA1.wCaps+1], A1_wCaps_LBA>>8
[227]	87	jz SHORT .StoreCHSfromAXBHBL ; Small old drive with CHS addressing only
[3]	88
[324]	89	; Store LBA 28/48 addressing and total sector count
[173]	90	call AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI
[324]	91	call StoreLbaAddressingAndTotalSectorCountFromBXDXAX
	92
	93	; Replace sector count with user defined if necessary
	94	call AccessDPT_GetPointerToDRVPARAMStoCSBX
	95	test BYTE [cs:bx+DRVPARAMS.wFlags], FLG_DRVPARAMS_USERLBA
	96	jz SHORT .KeepTotalSectorsFromAtaID
	97	mov ax, [cs:bx+DRVPARAMS.dwMaximumLBA]
	98	mov dx, [cs:bx+DRVPARAMS.dwMaximumLBA+2]
	99	xor bx, bx
	100
	101	; Compare user defined and ATA-ID sector count and select smaller
	102	cmp bx, [di+DPT.twLbaSectors+4]
	103	jb SHORT .StoreUserDefinedSectorCountToDPT
	104	cmp dx, [di+DPT.twLbaSectors+2]
	105	jb SHORT .StoreUserDefinedSectorCountToDPT
	106	ja SHORT .KeepTotalSectorsFromAtaID
	107	cmp ax, [di+DPT.twLbaSectors]
	108	jae SHORT .KeepTotalSectorsFromAtaID
	109	.StoreUserDefinedSectorCountToDPT:
	110	call StoreLbaAddressingAndTotalSectorCountFromBXDXAX
	111
	112	; Calculate L-CHS for old INT 13h
	113	.KeepTotalSectorsFromAtaID:
	114	mov bx, [di+DPT.twLbaSectors+4] ; Restore BX
	115	call AccessDPT_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH
[227]	116	mov [di+DPT.bLbaHeads], bl
	117	jmp SHORT .StoreBlockMode
[173]	118
[227]	119	;--------------------------------------------------------------------
	120	; .StoreUserDefinedPCHS
	121	; Parameters:
	122	; DS:DI: Ptr to Disk Parameter Table
	123	; ES:SI: Ptr to 512-byte ATA information read from the drive
	124	; CS:BP: Ptr to IDEVARS for the controller
	125	; Returns:
	126	; AX: Number of P-CHS cylinders
	127	; BH: Number of P-CHS sectors per track
	128	; BL: Number of P-CHS heads
	129	; Corrupts registers:
	130	; Nothing
	131	;--------------------------------------------------------------------
	132	.StoreUserDefinedPCHS:
[3]	133	call AccessDPT_GetPointerToDRVPARAMStoCSBX
	134	mov ax, [cs:bx+DRVPARAMS.wCylinders]
[99]	135	mov bx, [cs:bx+DRVPARAMS.wHeadsAndSectors]
[227]	136	; Fall to .StoreCHSfromAXBHBL
[3]	137
[227]	138	;--------------------------------------------------------------------
	139	; .StoreCHSfromAXBHBL
	140	; Parameters:
	141	; AX: Number of P-CHS cylinders
	142	; BH: Number of P-CHS sectors per track
	143	; BL: Number of P-CHS heads
	144	; DS:DI: Ptr to Disk Parameter Table
	145	; ES:SI: Ptr to 512-byte ATA information read from the drive
	146	; CS:BP: Ptr to IDEVARS for the controller
	147	; Returns:
	148	; AX: Number of P-CHS cylinders
	149	; BH: Number of P-CHS sectors per track
	150	; BL: Number of P-CHS heads
	151	; Corrupts registers:
	152	; CX
	153	;--------------------------------------------------------------------
	154	.StoreCHSfromAXBHBL:
[173]	155	push ax
[227]	156	push bx
	157	call AccessDPT_ShiftPCHinAXBLtoLCH ; Get number of bits to shift
	158	pop bx
[173]	159	pop ax
[227]	160	jcxz .StorePCHSfromAXDX ; Small drive so use L-CHS addressing
[3]	161
[227]	162	; Store P-CHS addressing mode and number of bits to shift in L-CHS to P-CHS translation
	163	or cl, ADDRESSING_MODE_PCHS<<ADDRESSING_MODE_FIELD_POSITION
	164	or [di+DPT.bFlagsLow], cl
	165	; Fall to .StoreChsFromAXBLBH
	166
[3]	167	;--------------------------------------------------------------------
[227]	168	; .StoreChsFromAXBLBH
[3]	169	; Parameters:
[227]	170	; AX: Number of P-CHS cylinders
	171	; BH: Number of P-CHS sectors per track
	172	; BL: Number of P-CHS heads
[3]	173	; DS:DI: Ptr to Disk Parameter Table
	174	; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]	175	; CS:BP: Ptr to IDEVARS for the controller
[3]	176	; Returns:
[99]	177	; Nothing
[3]	178	; Corrupts registers:
[227]	179	; Nothing
[3]	180	;--------------------------------------------------------------------
[227]	181	.StorePCHSfromAXDX:
	182	mov [di+DPT.wPchsCylinders], ax
	183	mov [di+DPT.wPchsHeadsAndSectors], bx
[99]	184	; Fall to .StoreBlockMode
[3]	185
	186	;--------------------------------------------------------------------
[99]	187	; .StoreBlockMode
[3]	188	; Parameters:
	189	; DS:DI: Ptr to Disk Parameter Table
	190	; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]	191	; CS:BP: Ptr to IDEVARS for the controller
[3]	192	; Returns:
[99]	193	; Nothing
[3]	194	; Corrupts registers:
[150]	195	; Nothing
[3]	196	;--------------------------------------------------------------------
[99]	197	.StoreBlockMode:
[150]	198	cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
	199	jbe SHORT .BlockModeTransfersNotSupported
[158]	200	or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
[150]	201	.BlockModeTransfersNotSupported:
	202	; Fall to .StoreDeviceSpecificParameters
[3]	203
	204	;--------------------------------------------------------------------
[150]	205	; .StoreDeviceSpecificParameters
[3]	206	; Parameters:
	207	; DS:DI: Ptr to Disk Parameter Table
	208	; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]	209	; CS:BP: Ptr to IDEVARS for the controller
[3]	210	; Returns:
[99]	211	; Nothing
[3]	212	; Corrupts registers:
[150]	213	; AX, BX, CX, DX
[3]	214	;--------------------------------------------------------------------
[150]	215	.StoreDeviceSpecificParameters:
	216	call Device_FinalizeDPT
[258]	217
[262]	218	;----------------------------------------------------------------------
	219	; Update drive counts (hard and floppy)
[294]	220	;----------------------------------------------------------------------
	221
[258]	222	%ifdef MODULE_SERIAL_FLOPPY
	223	;
	224	; These two instructions serve two purposes:
	225	; 1. If the drive is a floppy drive (CF set), then we effectively increment the counter.
[294]	226	; 2. If this is a hard disk, and there have been any floppy drives previously added, then the hard disk is
[258]	227	; effectively discarded. This is more of a safety check then code that should ever normally be hit (see below).
[294]	228	; Since the floppy DPT's come after the hard disk DPT's, without expensive (code size) code to relocate a DPT,
[258]	229	; this was necessary. Now, this situation shouldn't happen in normal operation, for a couple of reasons:
[294]	230	; A. xtidecfg always puts configured serial ports at the end of the IDEVARS list
[258]	231	; B. the auto serial code is always executed last
	232	; C. the serial server always returns floppy drives last
	233	;
	234	adc byte [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt], 0
[294]	235	jnz .AllDone
[258]	236	%else
	237	;
	238	; Even without floppy support enabled, we shouldn't try to mount a floppy image as a hard disk, which
[294]	239	; could lead to unpredictable results since no MBR will be present, etc. The server doesn't know that
[258]	240	; floppies are supported, so it is important to still fail here if a floppy is seen during the drive scan.
	241	;
	242	jc .AllDone
	243	%endif
	244
[150]	245	inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
[294]	246
	247	.AllDone:
[162]	248	clc
[3]	249	ret
[258]	250
[324]	251
	252	;--------------------------------------------------------------------
	253	; StoreLbaAddressingAndTotalSectorCountFromBXDXAX
	254	; Parameters:
	255	; BX:DX:AX: Total Sector Count
	256	; DS:DI: Ptr to Disk Parameter Table
	257	; Returns:
	258	; Nothing
	259	; Corrupts registers:
	260	; CX
	261	;--------------------------------------------------------------------
	262	StoreLbaAddressingAndTotalSectorCountFromBXDXAX:
	263	mov [di+DPT.twLbaSectors], ax
	264	mov [di+DPT.twLbaSectors+2], dx
	265	mov [di+DPT.twLbaSectors+4], bx
	266
	267	and BYTE [di+DPT.bFlagsLow], ~MASKL_DPT_ADDRESSING_MODE
	268	test bx, bx
[346]	269	jnz SHORT .SetLba48AddressingToDPT ; Must be LBA48
	270
	271	; Drives can report at most 0FFF FFFFh LBA28 sectors according to ATA specification.
	272	; That is (2^28)-1 so we can simply check if DH is zero or not.
	273	test dh, dh
[324]	274	jz SHORT .SetLba28AddressingToDPT
	275	.SetLba48AddressingToDPT:
	276	or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA48<<ADDRESSING_MODE_FIELD_POSITION
	277	.SetLba28AddressingToDPT:
	278	or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA28<<ADDRESSING_MODE_FIELD_POSITION
	279	ret

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