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source: xtideuniversalbios/trunk/Assembly_Library/Src/Util/Memory.asm @ 50

Last change on this file since 50 was 50, checked in by aitotat, 14 years ago
Changes to Assembly Library: Removed Memory_ExchangeSSBPwithESDI since it obviously corrupted stack. CGA detection is now only done once when initializing Display Context. Moved File Library defines to File.inc.
File size: 4.6 KB

Rev	Line
[41]	1	; File name : Memory.asm
	2	; Project name : Assembly Library
	3	; Created date : 14.7.2010
[50]	4	; Last update : 9.10.2010
[41]	5	; Author : Tomi Tilli
	6	; Description : Functions for memory access.
	7
	8	; Section containing code
	9	SECTION .text
	10
	11	;--------------------------------------------------------------------
[46]	12	; OPTIMIZE_STRING_OPERATION
[41]	13	; Parameters
[46]	14	; %1: Repeat instruction
	15	; %2: String instruction without size (for example MOVS and not MOVSB or MOVSW)
	16	; CX: Number of BYTEs to operate
	17	; DS:SI: Ptr to source data
	18	; ES:DI: Ptr to destination
[41]	19	; Returns:
[46]	20	; SI, DI: Updated by number of bytes operated
	21	; Corrupts registers:
[41]	22	; Nothing
[46]	23	;--------------------------------------------------------------------
	24	%macro OPTIMIZE_STRING_OPERATION 2
	25	push cx
	26
	27	shr cx, 1 ; Operate with WORDs for performance
	28	jcxz %%HandleRemainingByte
	29	%1 %2w
	30	%%HandleRemainingByte:
	31	jnc SHORT %%OperationCompleted
	32	%2b
	33
	34	ALIGN JUMP_ALIGN
	35	%%OperationCompleted:
	36	pop cx
	37	%endmacro
	38
	39
	40	;--------------------------------------------------------------------
	41	; Memory_CopyCXbytesFromDSSItoESDI
	42	; Parameters
	43	; CX: Number of bytes to copy
	44	; DS:SI: Ptr to source data
	45	; ES:DI: Ptr to destination buffer
	46	; Returns:
	47	; SI, DI: Updated by number of bytes copied
[41]	48	; Corrupts registers:
[46]	49	; Nothing
[41]	50	;--------------------------------------------------------------------
	51	ALIGN JUMP_ALIGN
[46]	52	Memory_CopyCXbytesFromDSSItoESDI:
	53	OPTIMIZE_STRING_OPERATION rep, movs
	54	ret
[41]	55
[46]	56
[41]	57	;--------------------------------------------------------------------
[46]	58	; Memory_ZeroSSBPwithSizeInCX
[41]	59	; Parameters
[46]	60	; CX: Number of bytes to zero
[41]	61	; SS:BP: Ptr to buffer to zero
	62	; Returns:
	63	; Nothing
	64	; Corrupts registers:
	65	; Nothing
	66	;--------------------------------------------------------------------
	67	ALIGN JUMP_ALIGN
[46]	68	Memory_ZeroSSBPwithSizeInCX:
[50]	69	push es
	70	push di
[41]	71	push ax
[50]	72	call Memory_CopySSBPtoESDI
[46]	73	call Memory_ZeroESDIwithSizeInCX
[41]	74	pop ax
[50]	75	pop di
	76	pop es
[41]	77	ret
	78
	79	;--------------------------------------------------------------------
[46]	80	; Memory_ZeroESDIwithSizeInCX
[41]	81	; Parameters
[46]	82	; CX: Number of bytes to zero
	83	; ES:DI: Ptr to destination buffer
[41]	84	; Returns:
[50]	85	; DI: Updated by number of BYTEs stored
[41]	86	; Corrupts registers:
	87	; AX
	88	;--------------------------------------------------------------------
	89	ALIGN JUMP_ALIGN
[46]	90	Memory_ZeroESDIwithSizeInCX:
[41]	91	xor ax, ax
[46]	92	; Fall to Memory_StoreCXbytesFromAccumToESDI
[41]	93
	94	;--------------------------------------------------------------------
[46]	95	; Memory_StoreCXbytesFromAccumToESDI
[41]	96	; Parameters
	97	; AX: Word to use to fill buffer
[46]	98	; CX: Number of BYTEs to store
	99	; ES:DI: Ptr to destination buffer
[41]	100	; Returns:
[50]	101	; DI: Updated by number of BYTEs stored
[41]	102	; Corrupts registers:
	103	; Nothing
	104	;--------------------------------------------------------------------
	105	ALIGN JUMP_ALIGN
[46]	106	Memory_StoreCXbytesFromAccumToESDI:
	107	OPTIMIZE_STRING_OPERATION rep, stos
[41]	108	ret
	109
	110
	111	;--------------------------------------------------------------------
	112	; Memory_ExchangeDSSIwithESDI
	113	; Parameters
	114	; Nothing
	115	; Returns:
[50]	116	; DS:SI and ES:DI are exchanged.
[41]	117	; Corrupts registers:
	118	; Nothing
	119	;--------------------------------------------------------------------
	120	ALIGN JUMP_ALIGN
	121	Memory_ExchangeDSSIwithESDI:
	122	push ds
	123	push es
	124	pop ds
	125	pop es
[50]	126	xchg si, di
[41]	127	ret
	128
	129
	130	;--------------------------------------------------------------------
	131	; Memory_CopySSBPtoESDI
[50]	132	; Memory_CopySSBPtoDSSI
	133	; Memory_CopyESDItoDSSI
[41]	134	; Parameters
	135	; Nothing
	136	; Returns:
[50]	137	; Copies farm pointer to different segment/pointer register pair
[41]	138	; Corrupts registers:
	139	; Nothing
	140	;--------------------------------------------------------------------
	141	ALIGN JUMP_ALIGN
	142	Memory_CopySSBPtoESDI:
	143	push ss
	144	pop es
	145	mov di, bp
	146	ret
	147
[50]	148	ALIGN JUMP_ALIGN
	149	Memory_CopySSBPtoDSSI:
	150	push ss
	151	pop ds
	152	mov si, bp
	153	ret
[41]	154
[50]	155	ALIGN JUMP_ALIGN
	156	Memory_CopyESDItoDSSI:
	157	push es
	158	pop ds
	159	mov si, di
	160	ret
	161
	162
[41]	163	;--------------------------------------------------------------------
	164	; Memory_SetZFifNullPointerInDSSI
	165	; Parameters
	166	; DS:SI: Far pointer
	167	; Returns:
	168	; ZF: Set if NULL pointer in DS:SI
	169	; Corrupts registers:
	170	; Nothing
	171	;--------------------------------------------------------------------
	172	ALIGN JUMP_ALIGN
	173	Memory_SetZFifNullPointerInDSSI:
	174	push ax
	175	mov ax, ds
	176	or ax, si
	177	pop ax
	178	ret
	179
	180
	181	;--------------------------------------------------------------------
	182	; Memory_ReserveCXbytesFromStackToDSSI
	183	; Parameters
	184	; CX: Number of bytes to reserve
	185	; Returns:
	186	; DS:SI: Ptr to reserved buffer
	187	; Corrupts registers:
	188	; AX
	189	;--------------------------------------------------------------------
	190	ALIGN JUMP_ALIGN
	191	Memory_ReserveCXbytesFromStackToDSSI:
	192	pop ax
	193	push ss
	194	pop ds
	195	sub sp, cx
	196	mov si, sp
	197	jmp ax

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