67 lines
949 B
NASM
67 lines
949 B
NASM
; important functions in this file: kprintf
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; write a character to kernel output
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; in: al
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printc:
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push ax
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push bx
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mov bx, 0x0000
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mov ah, 0x0e
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int 0x10
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pop bx
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pop ax
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ret
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; prints a nibble in hex
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; in: al
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print4:
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and al, 0x0F
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add al, 0x30
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cmp al, 0x3a
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jl printc
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add al, 0x07
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jmp printc
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; print a byte
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; in: al
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print8:
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push ax ; avoid destroying ah
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aam 16 ; high nibble moved into ah
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xchg ah,al ; high nibble first
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call print4
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xchg ah,al
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call print4
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pop ax
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ret
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; print a word
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; in: ax
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print16:
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xchg ah,al
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call print8
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xchg ah,al
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call print8
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ret
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; print a inline following its call opcode
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; the string ends with a nullbyte
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; trashes si
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print_inline:
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pop si
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push ax
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push bx
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mov bx, 0x0000
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.loop:
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lodsb
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cmp al, 0x00
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je .end
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mov ah, 0x0e
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int 0x10
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cmp al, 0x0D
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jmp .loop
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.end:
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pop bx
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pop ax
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push si
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ret
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