lib/print: shave off some bytes

lib/print.asm

@@ -1,37 +1,28 @@
 ; 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
 ; in: al
 print8:
   push ax ; avoid destroying ah
-  aam 16 ; high nibble moved into ah
-  xchg ah,al ; high nibble first
-  call print4
-  xchg ah,al
-  call print4
+  push bx
+  mov bx, 0x0000
+  aam 16 ; high nibble moved into ah, low nibble into al
+  add ax, 0x3030
+  push ax
+  xchg al, ah
+  call .nib
   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
 
 ; print a word