83 lines
1.5 KiB
NASM
Executable File
83 lines
1.5 KiB
NASM
Executable File
; SI = pointer to start of string to be printed
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; \n for newline
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; \t for tab
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; \\ for a single backslash
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os_print_string:
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pusha
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mov ah, 0Eh ; int 10h teletype function, we're telling the BIOS we will print something
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.repeat:
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lodsb ; Get char from si into al
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cmp al, 0 ; Compare al to 0
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je .done ; If char is zero, end of string
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cmp al, 5Ch ; backslash
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je .backslash
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int 10h ; Otherwise, print it
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jmp .repeat ; And move on to next char
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.backslash: ; If there is a '\', do what it says, \n for newline, \t for tab etc
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lodsb
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dec si
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cmp al, 6Eh ; 'n'
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je .newline
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cmp al, 74h ; \t
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je .tab
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cmp al, 5Ch ; '\'
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je .another_backslash
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jmp .repeat
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.newline:
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mov al, 0Ah ; new line
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int 10h
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mov al, 0Dh ; carriage return
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int 10h
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jmp .finish_backslash
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.tab:
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mov al, 09h ; tab
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int 10h
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jmp .finish_backslash
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.another_backslash: ; This just prints 1 backslash
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mov al, 5Ch
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int 10h
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jmp .finish_backslash
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.finish_backslash:
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inc si
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jmp .repeat
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.done:
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popa
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ret
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; --------------------------------------------
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os_print_newline:
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pusha
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mov ah, 0Eh
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mov al, 13
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int 10h
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mov al, 10
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int 10h
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popa
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ret
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; -------------------------------------------
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os_set_text_mode:
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pusha
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; Set mode = 80x25 (text mode)
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mov ah, 00h
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mov al, 03h
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int 10h
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; Move cursor to the top left
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mov ah, 02h
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mov dh, 0
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mov dl, 0
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int 10h
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popa
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ret
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