source: xtideuniversalbios/trunk/Assembly_Library/Src/Util/Memory.asm@ 218

Last change on this file since 218 was 194, checked in by gregli@…, 13 years ago

ifdef'd out more unused code. Also added a tool for looking through the listing and the output of the precompiler to aid in finding dead code. Some changes in the files are to add annotations for the tool to avoid false positives.
File size: 3.3 KB
Line 
1; Project name : Assembly Library
2; Description : Functions for memory access.
3
4; Section containing code
5SECTION .text
6
7;--------------------------------------------------------------------
8; OPTIMIZE_STRING_OPERATION
9; Parameters
10; %1: Repeat instruction
11; %2: String instruction without size (for example MOVS and not MOVSB or MOVSW)
12; CX: Number of BYTEs to operate
13; DS:SI: Ptr to source data
14; ES:DI: Ptr to destination
15; Returns:
16; SI, DI: Updated by number of bytes operated
17; Corrupts registers:
18; Nothing
19;--------------------------------------------------------------------
20%macro OPTIMIZE_STRING_OPERATION 2
21 push cx
22
23 shr cx, 1 ; Operate with WORDs for performance
24 jz %%HandleRemainingByte
25 %1 %2w
26%%HandleRemainingByte:
27 jnc SHORT %%OperationCompleted
28 %2b
29
30ALIGN JUMP_ALIGN
31%%OperationCompleted:
32 pop cx
33%endmacro
34
35
36;--------------------------------------------------------------------
37; Memory_CopyCXbytesFromDSSItoESDI
38; Parameters
39; CX: Number of bytes to copy
40; DS:SI: Ptr to source data
41; ES:DI: Ptr to destination buffer
42; Returns:
43; SI, DI: Updated by number of bytes copied
44; Corrupts registers:
45; Nothing
46;--------------------------------------------------------------------
47%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
48ALIGN JUMP_ALIGN
49Memory_CopyCXbytesFromDSSItoESDI:
50 OPTIMIZE_STRING_OPERATION rep, movs
51 ret
52%endif
53
54
55;--------------------------------------------------------------------
56; Memory_ZeroSSBPwithSizeInCX
57; Parameters
58; CX: Number of bytes to zero
59; SS:BP: Ptr to buffer to zero
60; Returns:
61; Nothing
62; Corrupts registers:
63; Nothing
64;--------------------------------------------------------------------
65ALIGN JUMP_ALIGN
66Memory_ZeroSSBPwithSizeInCX:
67 push es
68 push di
69 push ax
70 call Registers_CopySSBPtoESDI
71 call Memory_ZeroESDIwithSizeInCX
72 pop ax
73 pop di
74 pop es
75 ret
76
77;--------------------------------------------------------------------
78; Memory_ZeroESDIwithSizeInCX
79; Parameters
80; CX: Number of bytes to zero
81; ES:DI: Ptr to destination buffer
82; Returns:
83; DI: Updated by number of BYTEs stored
84; Corrupts registers:
85; AX
86;--------------------------------------------------------------------
87ALIGN JUMP_ALIGN
88Memory_ZeroESDIwithSizeInCX:
89 xor ax, ax
90 ; Fall to Memory_StoreCXbytesFromAccumToESDI
91
92;--------------------------------------------------------------------
93; Memory_StoreCXbytesFromAccumToESDI
94; Parameters
95; AX: Word to use to fill buffer
96; CX: Number of BYTEs to store
97; ES:DI: Ptr to destination buffer
98; Returns:
99; DI: Updated by number of BYTEs stored
100; Corrupts registers:
101; Nothing
102;--------------------------------------------------------------------
103ALIGN JUMP_ALIGN
104Memory_StoreCXbytesFromAccumToESDI:
105 OPTIMIZE_STRING_OPERATION rep, stos
106 ret
107
108
109;--------------------------------------------------------------------
110; Memory_ReserveCXbytesFromStackToDSSI
111; Parameters
112; CX: Number of bytes to reserve
113; Returns:
114; DS:SI: Ptr to reserved buffer
115; Corrupts registers:
116; AX
117;--------------------------------------------------------------------
118%ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
119ALIGN JUMP_ALIGN
120Memory_ReserveCXbytesFromStackToDSSI:
121 pop ax
122 push ss
123 pop ds
124 sub sp, cx
125 mov si, sp
126 jmp ax
127%endif
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