source: xtideuniversalbios/trunk/Assembly_Library/Inc/Macros.inc @ 119

Last change on this file since 119 was 119, checked in by aitotat, 13 years ago

Changes to Assembly Library:

  • Moved LOAD_BDA_SEGMENT_TO to Macros.inc.
File size: 3.0 KB
Line 
1; Project name  :   Assembly Library
2; Description   :   This is the place to put various generic macros.
3;                   Should be included immediately after emulate.inc
4%ifndef MACROS_INC
5%define MACROS_INC
6
7;--------------------------------------------------------------------
8; Skips the immediately following 2 byte instruction by using it
9; as an immediate value to a dummy instruction.
10; Destroys the contents of %1.
11;
12; SKIP2B
13;   Parameters:
14;       %1:     Any 16 bit general purpose register or F for flags.
15;   Returns:
16;       Nothing
17;   Corrupts registers:
18;       %1
19;--------------------------------------------------------------------
20%macro SKIP2B 1
21    %ifidni     %1, f
22        db  03Dh                    ; Opcode byte for CMP AX, <immed>
23        ;db 0A9h                    ; Alt. version TEST AX, <immed>
24    %elifidni   %1, ax
25        db  0B8h                    ; Opcode byte for MOV AX, <immed>
26    %elifidni   %1, cx
27        db  0B9h                    ; Opcode byte for MOV CX, <immed>
28    %elifidni   %1, dx
29        db  0BAh                    ; Opcode byte for MOV DX, <immed>
30    %elifidni   %1, bx
31        db  0BBh                    ; Opcode byte for MOV BX, <immed>
32    %elifidni   %1, sp
33        db  0BCh                    ; Opcode byte for MOV SP, <immed>
34    %elifidni   %1, bp
35        db  0BDh                    ; Opcode byte for MOV BP, <immed>
36    %elifidni   %1, si
37        db  0BEh                    ; Opcode byte for MOV SI, <immed>
38    %elifidni   %1, di
39        db  0BFh                    ; Opcode byte for MOV DI, <immed>
40    %else
41        %error "Invalid parameter passed to SKIP2B"
42    %endif
43%endmacro
44
45
46;--------------------------------------------------------------------
47; Load BDA (Bios Data Area) segment to wanted segment register.
48;
49; Use an exclamation point (!) as the third parameter when you want
50; to force the use of the register in the second parameter. This is
51; useful when that register needs to be zeroed in subsequent code or
52; when stack usage is undesirable (ie speed is critical).
53;
54; LOAD_BDA_SEGMENT_TO
55;   Parameters:
56;       %1:     Destination Segment Register
57;       %2:     Temporary WORD Register
58;       %3:     Can be ! or empty
59;   Returns:
60;       %1:     BDA segment (zero)
61;   Corrupts registers:
62;       %2
63;--------------------------------------------------------------------
64%macro LOAD_BDA_SEGMENT_TO 2-3
65%ifndef USE_186
66    xor     %2, %2
67    mov     %1, %2
68%elifidn %3, !
69    xor     %2, %2
70    mov     %1, %2
71%else
72    push    BYTE 0
73    pop     %1
74%endif
75%endmacro
76
77
78;--------------------------------------------------------------------
79; eENTER_STRUCT
80;   Parameters:
81;       %1:     Number of bytes to reserve from stack
82;   Returns:
83;       SS:BP:  Ptr to beginning of struct reserved from stack
84;   Corrupts registers:
85;       FLAGS
86;--------------------------------------------------------------------
87%macro eENTER_STRUCT 1
88    push    bp
89    sub     sp, %1
90    mov     bp, sp
91%endmacro
92
93;--------------------------------------------------------------------
94; eLEAVE_STRUCT
95;   Parameters:
96;       %1:     Number of bytes reserved with eENTER_STRUCT
97;   Returns:
98;       BP:     What it was before eENTER_STRUCT
99;   Corrupts registers:
100;       FLAGS
101;--------------------------------------------------------------------
102%macro eLEAVE_STRUCT 1
103    add     sp, %1
104    pop     bp
105%endmacro
106
107
108%endif ; MACROS_INC
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