Revamp debugger, including support for printing padded numbers

lib/printf.inc

@@ -48,24 +48,46 @@ printf:
   call print_string
   jmp .loop
 
+; converts a integer to ascii
+; in    ax      input integer
+;       bx      base
+;	cx	minimum number of digits
+; out   bx      garbled
+;       dx      garbled
+print_number_padded:
+  xor dx, dx
+  div bx
+  push dx
+  dec cx
+  jz .nopad
+  call print_number_padded
+  jmp print_number.end
+.nopad:
+  call print_number
+  jmp print_number.end
+
+; converts a integer to ascii
+; in	ax	input integer
+;	bx	base
+; out	bx	garbled
+;	dx	garbled
 print_number:
   xor dx, dx
   div bx ; ax = dx:ax / 10, dx = dx:ax % 10
-  and ax, ax
-  jz .print
   push dx
+  and ax, ax
+  jz .end
   call print_number
-  pop dx
-.print:
-  mov al, dl
-  add al, 0x30
-  cmp al, 0x3A
-  jl .noadj
-  add al, 0x07
-.noadj:
+.end:
+  pop bx
+  xor bh, bh
+  add bx, print_chars
+  mov al, [cs:bx]
   call putc
   ret
 
+; putc's a string
+; in	DS:AX	null-terminated string
 print_string:
   push si
   mov si, ax
@@ -77,4 +99,7 @@ print_string:
   jmp .loop
 .end:
   pop si
-  ret
+  ret
+
+print_chars:
+  db "0123456789ABCDEF"