| [41] | 1 | ; Project name : Assembly Library
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| 2 | ; Description : Functions for managing display cursor.
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| 3 |
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| 4 | ; Section containing code
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| 5 | SECTION .text
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| 6 |
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| 7 | ;--------------------------------------------------------------------
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| 8 | ; DisplayCursor_SetShapeFromAX
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| 9 | ; Parameters:
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| 10 | ; AX: Cursor shape (AH=Start scan line, AL=End scan line)
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| 11 | ; DS: BDA segment (zero)
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| 12 | ; Returns:
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| 13 | ; Nothing
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| 14 | ; Corrupts registers:
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| 15 | ; Nothing
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| 16 | ;--------------------------------------------------------------------
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| 17 | ALIGN JUMP_ALIGN
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| 18 | DisplayCursor_SetShapeFromAX:
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| 19 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], ax
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| 20 | ret
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| 21 |
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| 22 |
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| 23 | ;--------------------------------------------------------------------
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| 24 | ; DisplayCursor_SetCoordinatesFromAX
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| 25 | ; Parameters:
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| 26 | ; AL: Cursor column (X-coordinate)
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| 27 | ; AH: Cursor row (Y-coordinate)
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| 28 | ; DS: BDA segment (zero)
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| 29 | ; Returns:
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| 30 | ; DI: Offset to cursor location in video RAM
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| 31 | ; Corrupts registers:
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| 32 | ; AX, DX
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| 33 | ;--------------------------------------------------------------------
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| 34 | ALIGN JUMP_ALIGN
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| 35 | DisplayCursor_SetCoordinatesFromAX:
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| 36 | xchg dx, ax
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| 37 | mov ax, [VIDEO_BDA.wColumns] ; Column count, 40 or 80
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| 38 | mul dh ; AX = Column count * row index
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| [101] | 39 | xor dh, dh
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| 40 | add ax, dx ; Add column offset
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| [41] | 41 | shl ax, 1 ; Convert to WORD offset
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| [101] | 42 | add ax, [VIDEO_BDA.wPageOffset] ; AX = Video RAM offset
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| 43 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax
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| 44 | xchg di, ax
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| [41] | 45 | ret
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| 46 |
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| 47 |
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| 48 | ;--------------------------------------------------------------------
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| 49 | ; DisplayCursor_GetSoftwareCoordinatesToAX
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| 50 | ; Parameters:
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| 51 | ; AX: Offset to cursor location in selected page
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| 52 | ; DS: BDA segment (zero)
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| 53 | ; Returns:
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| 54 | ; AL: Cursor column (X-coordinate)
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| 55 | ; AH: Cursor row (Y-coordinate)
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| 56 | ; Corrupts registers:
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| 57 | ; Nothing
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| 58 | ;--------------------------------------------------------------------
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| 59 | ALIGN JUMP_ALIGN
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| 60 | DisplayCursor_GetSoftwareCoordinatesToAX:
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| 61 | mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
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| 62 | sub ax, [VIDEO_BDA.wPageOffset]
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| 63 | shr ax, 1 ; WORD offset to character offset
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| 64 | div BYTE [VIDEO_BDA.wColumns] ; AL = full rows, AH = column index for last row
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| 65 | xchg al, ah
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| 66 | ret
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| 67 |
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| 68 |
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| 69 | ;--------------------------------------------------------------------
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| 70 | ; DisplayCursor_GetHardwareCoordinatesToAX
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| 71 | ; Parameters:
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| 72 | ; DS: BDA segment (zero)
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| 73 | ; Returns:
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| 74 | ; AL: Hardware cursor column (X-coordinate)
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| 75 | ; AH: Hardware cursor row (Y-coordinate)
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| 76 | ; Corrupts registers:
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| 77 | ; DX
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| 78 | ;--------------------------------------------------------------------
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| 79 | ALIGN JUMP_ALIGN
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| 80 | DisplayCursor_GetHardwareCoordinatesToAX:
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| 81 | push cx
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| 82 | push bx
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| 83 |
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| 84 | mov ah, GET_CURSOR_POSITION_AND_SIZE
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| 85 | mov bh, [VIDEO_BDA.bActivePage]
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| 86 | int BIOS_VIDEO_INTERRUPT_10h
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| 87 | xchg ax, dx
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| 88 |
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| 89 | pop bx
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| 90 | pop cx
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| 91 | ret
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| 92 |
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| 93 |
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| 94 | ;--------------------------------------------------------------------
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| 95 | ; DisplayCursor_SynchronizeShapeToHardware
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| 96 | ; Parameters:
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| 97 | ; DS: BDA segment (zero)
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| 98 | ; Returns:
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| 99 | ; Nothing
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| 100 | ; Corrupts registers:
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| 101 | ; AX, DX
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| 102 | ;--------------------------------------------------------------------
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| 103 | ALIGN JUMP_ALIGN
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| 104 | DisplayCursor_SynchronizeShapeToHardware:
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| 105 | mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape]
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| 106 | ; Fall to .SetHardwareCursorShapeFromDX
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| 107 |
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| 108 | ;--------------------------------------------------------------------
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| 109 | ; .SetHardwareCursorShapeFromDX
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| 110 | ; Parameters:
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| 111 | ; DX: Cursor shape
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| 112 | ; DS: BDA segment (zero)
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| 113 | ; Returns:
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| 114 | ; Nothing
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| 115 | ; Corrupts registers:
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| 116 | ; AX
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| 117 | ;--------------------------------------------------------------------
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| 118 | .SetHardwareCursorShapeFromDX:
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| 119 | cmp dx, [VIDEO_BDA.wCursorShape]
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| 120 | je SHORT .Return ; Return if no changes
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| 121 | push cx
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| 122 | mov cx, dx ; BIOS wants cursor shape in CX
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| 123 | mov al, [VIDEO_BDA.bMode] ; Load video mode to prevent lock ups on some BIOSes
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| 124 | mov ah, SET_TEXT_MODE_CURSOR_SHAPE
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| 125 | int BIOS_VIDEO_INTERRUPT_10h
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| 126 | pop cx
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| 127 | .Return:
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| 128 | ret
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| 129 |
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| 130 |
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| 131 | ;--------------------------------------------------------------------
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| 132 | ; DisplayCursor_SynchronizeCoordinatesToHardware
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| 133 | ; Parameters:
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| 134 | ; DS: BDA segment (zero)
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| 135 | ; Returns:
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| 136 | ; Nothing
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| 137 | ; Corrupts registers:
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| 138 | ; AX, DX
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| 139 | ;--------------------------------------------------------------------
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| 140 | ALIGN JUMP_ALIGN
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| 141 | DisplayCursor_SynchronizeCoordinatesToHardware:
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| 142 | call DisplayCursor_GetSoftwareCoordinatesToAX
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| 143 | ; Fall to .SetHardwareCursorCoordinatesFromAX
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| 144 |
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| 145 | ;--------------------------------------------------------------------
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| 146 | ; .SetHardwareCursorCoordinatesFromAX
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| 147 | ; Parameters:
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| 148 | ; AL: Cursor column (X-coordinate)
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| 149 | ; AH: Cursor row (Y-coordinate)
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| 150 | ; DS: BDA segment (zero)
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| 151 | ; Returns:
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| 152 | ; Nothing
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| 153 | ; Corrupts registers:
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| 154 | ; AX, DX
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| 155 | ;--------------------------------------------------------------------
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| 156 | .SetHardwareCursorCoordinatesFromAX:
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| 157 | push bx
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| 158 | xchg dx, ax ; BIOS wants coordinates in DX
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| 159 | mov ah, SET_CURSOR_POSITION
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| 160 | mov bh, [VIDEO_BDA.bActivePage]
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| 161 | int BIOS_VIDEO_INTERRUPT_10h
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| 162 | pop bx
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| 163 | ret
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