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lib/print: shave off some bytes

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Nero 2019-03-31 12:22:42 +00:00
parent 9aa032a90c
commit 1c4a0cf185
1 changed files with 18 additions and 27 deletions
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45
lib/print.asm
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@ -1,37 +1,28 @@
; important functions in this file: kprintf ; important functions in this file: kprintf
; write a character to kernel output
; in: al
printc:
push ax
push bx
mov bx, 0x0000
mov ah, 0x0e
int 0x10
pop bx
pop ax
ret
; prints a nibble in hex
; in: al
print4:
and al, 0x0F
add al, 0x30
cmp al, 0x3a
jl printc
add al, 0x07
jmp printc
; print a byte ; print a byte
; in: al ; in: al
print8: print8:
push ax ; avoid destroying ah push ax ; avoid destroying ah
aam 16 ; high nibble moved into ah push bx
xchg ah,al ; high nibble first mov bx, 0x0000
call print4 aam 16 ; high nibble moved into ah, low nibble into al
xchg ah,al add ax, 0x3030
call print4 push ax
xchg al, ah
call .nib
pop ax pop ax
call .nib
pop bx
pop ax
ret
.nib:
cmp al, 0x3a
jl .out
add al, 0x07
.out:
mov ah, 0x0e
int 0x10
ret ret
; print a word ; print a word