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source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/FindDPT.asm@ 525

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Last change on this file since 525 was 524, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

Min time to display hotkeys finally work correctly.
AT builds do not copy existing INT 13h handler to 40h by default, XT builds do.
Interrupts are enabled for Primary and Secondary controller by default on AT builds.

File size: 9.5 KB

Rev	Line
[150]	1	; Project name : XTIDE Universal BIOS
[3]	2	; Description : Functions for finding Disk Parameter Table.
	3
[376]	4	;
	5	; XTIDE Universal BIOS and Associated Tools
	6	; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team.
	7	;
	8	; This program is free software; you can redistribute it and/or modify
	9	; it under the terms of the GNU General Public License as published by
	10	; the Free Software Foundation; either version 2 of the License, or
	11	; (at your option) any later version.
	12	;
	13	; This program is distributed in the hope that it will be useful,
	14	; but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	; GNU General Public License for more details.
	17	; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
	18	;
	19
[3]	20	; Section containing code
	21	SECTION .text
	22
	23	;--------------------------------------------------------------------
[262]	24	; Checks if drive is handled by this BIOS, and return DPT pointer.
[3]	25	;
[294]	26	; FindDPT_ForDriveNumberInDL
[3]	27	; Parameters:
[262]	28	; DL: Drive number
[3]	29	; DS: RAMVARS segment
	30	; Returns:
[262]	31	; CF: Cleared if drive is handled by this BIOS
	32	; Set if drive belongs to some other BIOS
	33	; DI: DPT Pointer if drive is handled by this BIOS
	34	; Zero if drive belongs to some other BIOS
[3]	35	; Corrupts registers:
[262]	36	; Nothing
[150]	37	;--------------------------------------------------------------------
	38	ALIGN JUMP_ALIGN
[294]	39	FindDPT_ForDriveNumberInDL:
[262]	40	xchg di, ax ; Save the contents of AX in DI
	41
[294]	42	;
[262]	43	; Check Our Hard Disks
	44	;
[433]	45	mov ax, [RAMVARS.wFirstDrvAndCount] ; Drive count to AH, First number to AL
[262]	46	add ah, al ; One past last drive to AH
	47
[258]	48	%ifdef MODULE_SERIAL_FLOPPY
[262]	49	cmp dl, ah ; Above last supported?
	50	jae SHORT .HardDiskNotHandledByThisBIOS
[294]	51
[262]	52	cmp dl, al ; Below first supported?
	53	jae SHORT .CalcDPTForDriveNumber
	54
[294]	55	ALIGN JUMP_ALIGN
	56	.HardDiskNotHandledByThisBIOS:
[262]	57	;
	58	; Check Our Floppy Disks
[294]	59	;
[262]	60	call RamVars_UnpackFlopCntAndFirstToAL
	61	js SHORT .DiskIsNotHandledByThisBIOS
[294]	62
[277]	63	cbw ; Always 0h (no floppy drive covered above)
	64	adc ah, al ; Add in first drive number and number of drives
	65
[262]	66	cmp ah, dl ; Check second drive if two, first drive if only one
	67	jz SHORT .CalcDPTForDriveNumber
	68	cmp al, dl ; Check first drive in all cases, redundant but OK to repeat
[294]	69	jnz SHORT .DiskIsNotHandledByThisBIOS
[262]	70	%else
[294]	71	cmp dl, ah ; Above last supported?
[262]	72	jae SHORT .DiskIsNotHandledByThisBIOS
[294]	73
[262]	74	cmp dl, al ; Below first supported?
[294]	75	jb SHORT .DiskIsNotHandledByThisBIOS
[258]	76	%endif
[262]	77	; fall-through to CalcDPTForDriveNumber
[150]	78
	79	;--------------------------------------------------------------------
	80	; Finds Disk Parameter Table for drive number.
[294]	81	; Not intended to be called except by FindDPT_ForDriveNumberInDL
[150]	82	;
[262]	83	; CalcDPTForDriveNumber
[150]	84	; Parameters:
	85	; DL: Drive number
	86	; DS: RAMVARS segment
[294]	87	; DI: Saved copy of AX from entry at FindDPT_ForDriveNumberInDL
[150]	88	; Returns:
	89	; DS:DI: Ptr to DPT
[262]	90	; CF: Clear
[150]	91	; Corrupts registers:
[3]	92	; Nothing
	93	;--------------------------------------------------------------------
	94	ALIGN JUMP_ALIGN
[262]	95	.CalcDPTForDriveNumber:
[150]	96	push dx
[3]	97
[258]	98	%ifdef MODULE_SERIAL_FLOPPY
[433]	99	mov ax, [RAMVARS.wFirstDrvAndCount]
[294]	100
[258]	101	test dl, dl
	102	js .harddisk
	103
	104	call RamVars_UnpackFlopCntAndFirstToAL
	105	add dl, ah ; add in end of hard disk DPT list, floppies start immediately after
[294]	106
	107	ALIGN JUMP_ALIGN
[258]	108	.harddisk:
	109	sub dl, al ; subtract off beginning of either hard disk or floppy list (as appropriate)
	110	%else
	111	sub dl, [RAMVARS.bFirstDrv] ; subtract off beginning of hard disk list
	112	%endif
[262]	113
[294]	114	.CalcDPTForNewDrive:
[150]	115	mov al, LARGEST_DPT_SIZE
[294]	116
[150]	117	mul dl
[522]	118	add ax, RAMVARS_size ; Clears CF (will not overflow)
[3]	119
[150]	120	pop dx
[262]	121
	122	xchg di, ax ; Restore AX from entry at FindDPT_ForDriveNumber, put DPT pointer in DI
[150]	123	ret
	124
[294]	125	ALIGN JUMP_ALIGN
	126	.DiskIsNotHandledByThisBIOS:
[259]	127	;
[262]	128	; Drive not found...
	129	;
	130	xor ax, ax ; Clear DPT pointer
[294]	131	stc ; Is not supported by our BIOS
	132
[262]	133	xchg di, ax ; Restore AX from save at top
[259]	134	ret
	135
[271]	136
[259]	137	;--------------------------------------------------------------------
[521]	138	; FindDPT_MasterOrSingleForIdevarsOffsetInDL
[271]	139	; Parameters:
	140	; DL: Offset to IDEVARS to search for
	141	; DS: RAMVARS segment
	142	; Returns:
	143	; DS:DI: Ptr to first DPT with same IDEVARS as in DL
	144	; CF: Clear if wanted DPT found
	145	; Set if DPT not found, or no DPTs present
	146	; Corrupts registers:
	147	; SI
	148	;--------------------------------------------------------------------
[521]	149	FindDPT_MasterOrSingleForIdevarsOffsetInDL:
[271]	150	mov si, IterateFindFirstDPTforIdevars ; iteration routine (see below)
	151	jmp SHORT FindDPT_IterateAllDPTs ; look for the first drive on this controller, if any
	152
	153	;--------------------------------------------------------------------
[521]	154	; FindDPT_SlaveForIdevarsOffsetInDL
	155	; Parameters:
	156	; DL: Offset to IDEVARS to search for
	157	; DS: RAMVARS segment
	158	; Returns:
	159	; DS:DI: Ptr to second DPT with same IDEVARS as in DL
	160	; CF: Clear if wanted DPT found
	161	; Set if DPT not found, or no DPTs present
	162	; Corrupts registers:
	163	; SI
	164	;--------------------------------------------------------------------
	165	FindDPT_SlaveForIdevarsOffsetInDL:
	166	mov si, IterateFindSecondDPTforIdevars ; iteration routine (see below)
	167	jmp SHORT FindDPT_IterateAllDPTs ; look for the second drive on this controller, if any
	168
	169	;--------------------------------------------------------------------
	170	; Iteration routines for FindDPT_MasterOrSingleForIdevarsOffsetInDL and
	171	; FindDPT_SlaveForIdevarsOffsetInDL, for use with IterateAllDPTs
[294]	172	;
[271]	173	; Returns when DPT is found on the controller with Idevars offset in DL
	174	;
[521]	175	; IterateFindSecondDPTforIdevars
[271]	176	; IterateFindFirstDPTforIdevars
	177	; DL: Offset to IDEVARS to search from DPTs
[524]	178	; SI: Offset to this callback function
[271]	179	; DS:DI: Ptr to DPT to examine
	180	; Returns:
	181	; CF: Clear if wanted DPT found
	182	; Set if wrong DPT
	183	;--------------------------------------------------------------------
[521]	184	IterateFindSecondDPTforIdevars:
	185	call IterateFindFirstDPTforIdevars
[524]	186	jc SHORT .WrongController
	187	mov si, IterateFindFirstDPTforIdevars
	188	.WrongController:
	189	stc
	190	ret
[521]	191
[294]	192	IterateFindFirstDPTforIdevars:
[271]	193	cmp dl, [di+DPT.bIdevarsOffset] ; Clears CF if matched
	194	je .done
	195	stc ; Set CF for not found
[294]	196	.done:
[271]	197	ret
	198
	199
	200	;--------------------------------------------------------------------
[262]	201	; Finds pointer to first unused Disk Parameter Table.
	202	; Should only be used before DetectDrives is complete (not valid after this time).
[3]	203	;
[262]	204	; FindDPT_ForNewDriveToDSDI
[3]	205	; Parameters:
	206	; DS: RAMVARS segment
	207	; Returns:
[262]	208	; DS:DI: Ptr to first unused DPT
[3]	209	; Corrupts registers:
[262]	210	; AX
[3]	211	;--------------------------------------------------------------------
[262]	212	ALIGN JUMP_ALIGN
	213	FindDPT_ForNewDriveToDSDI:
	214	push dx
[294]	215
[262]	216	%ifdef MODULE_SERIAL_FLOPPY
	217	mov dx, [RAMVARS.wDrvCntAndFlopCnt]
	218	add dl, dh
	219	%else
	220	mov dl, [RAMVARS.bDrvCnt]
	221	%endif
[294]	222
[262]	223	jmp short FindDPT_ForDriveNumberInDL.CalcDPTForNewDrive
[3]	224
[152]	225	;--------------------------------------------------------------------
[233]	226	; IterateToDptWithFlagsHighInBL
[152]	227	; Parameters:
	228	; DS:DI: Ptr to DPT to examine
[294]	229	; BL: Bit(s) to test in DPT.bFlagsHigh
[152]	230	; Returns:
[262]	231	; CF: Clear if wanted DPT found
	232	; Set if wrong DPT
[152]	233	; Corrupts registers:
	234	; Nothing
	235	;--------------------------------------------------------------------
	236	ALIGN JUMP_ALIGN
[294]	237	IterateToDptWithFlagsHighInBL:
	238	test [di+DPT.bFlagsHigh], bl ; Clears CF
[262]	239	jnz SHORT .ReturnRightDPT
	240	stc
[294]	241	.ReturnRightDPT:
[3]	242	ret
	243
	244	;--------------------------------------------------------------------
[233]	245	; FindDPT_ToDSDIforSerialDevice
[161]	246	; Parameters:
	247	; DS: RAMVARS segment
	248	; Returns:
	249	; DS:DI: Ptr to DPT
	250	; CF: Set if wanted DPT found
	251	; Cleared if DPT not found
	252	; Corrupts registers:
[203]	253	; SI
[161]	254	;--------------------------------------------------------------------
[265]	255	%ifdef MODULE_SERIAL
[294]	256	ALIGN JUMP_ALIGN
	257	FindDPT_ToDSDIforSerialDevice:
[233]	258	mov bl, FLGH_DPT_SERIAL_DEVICE
	259	; fall-through
[265]	260	%endif
[294]	261
[233]	262	;--------------------------------------------------------------------
	263	; FindDPT_ToDSDIforFlagsHigh
	264	; Parameters:
	265	; DS: RAMVARS segment
	266	; BL: Bit(s) to test in DPT.bFlagsHigh
	267	; Returns:
	268	; DS:DI: Ptr to DPT
	269	; CF: Set if wanted DPT found
	270	; Cleared if DPT not found
	271	; Corrupts registers:
	272	; SI
	273	;--------------------------------------------------------------------
[489]	274	%ifdef MODULE_IRQ
[161]	275	ALIGN JUMP_ALIGN
[489]	276	FindDPT_ToDSDIforFlagsHighInBL:
	277	%endif
[233]	278	mov si, IterateToDptWithFlagsHighInBL
[161]	279	; Fall to IterateAllDPTs
	280
	281	;--------------------------------------------------------------------
[3]	282	; Iterates all Disk Parameter Tables.
	283	;
[271]	284	; FindDPT_IterateAllDPTs
[3]	285	; Parameters:
[152]	286	; AX,BX,DX: Parameters to callback function
	287	; CS:SI: Ptr to callback function
[262]	288	; Callback routine should return CF=clear if found
[152]	289	; DS: RAMVARS segment
[3]	290	; Returns:
[152]	291	; DS:DI: Ptr to wanted DPT (if found)
[258]	292	; If not found, points to first empty DPT
[262]	293	; CF: Clear if wanted DPT found
	294	; Set if DPT not found, or no DPTs present
[3]	295	; Corrupts registers:
[150]	296	; Nothing unless corrupted by callback function
[3]	297	;--------------------------------------------------------------------
	298	ALIGN JUMP_ALIGN
[271]	299	FindDPT_IterateAllDPTs:
[3]	300	push cx
[258]	301
	302	mov di, RAMVARS_size ; Point DS:DI to first DPT
[294]	303	eMOVZX cx, [RAMVARS.bDrvCnt]
[262]	304	jcxz .NotFound ; Return if no drives
[294]	305
[3]	306	ALIGN JUMP_ALIGN
	307	.LoopWhileDPTsLeft:
	308	call si ; Is wanted DPT?
[262]	309	jnc SHORT .Found ; If so, return
	310	add di, BYTE LARGEST_DPT_SIZE ; Point to next DPT
[258]	311	loop .LoopWhileDPTsLeft
[262]	312
[3]	313	ALIGN JUMP_ALIGN
[262]	314	.NotFound:
	315	stc
	316
	317	ALIGN JUMP_ALIGN
	318	.Found:
[3]	319	pop cx
	320	ret

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