24 lines
805 B
NASM
24 lines
805 B
NASM
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[bits 32]
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; Define some constants
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VIDEO_MEMORY equ 0xb8000
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WHITE_ON_BLACK equ 0x0f
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; prints a null - terminated string pointed to by EDX
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print_string_pm:
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pusha
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mov edx, VIDEO_MEMORY ; Set edx to the start of vid mem.
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print_string_pm_loop:
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mov al, [ ebx ] ; Store the char at EBX in AL
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mov ah, WHITE_ON_BLACK ; Store the attributes in AH
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cmp al, 0 ; if ( al == 0) , at end of string , so
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je print_string_pm_done ; jump to done
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mov [ edx ], ax ; Store char and attributes at current
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; character cell.
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add ebx, 1 ; Increment EBX to the next char in string.
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add edx, 2 ; Move to next character cell in vid mem.
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jmp print_string_pm_loop ; loop around to print the next char.
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print_string_pm_done:
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popa
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ret ; Return from the function
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