section .text,text
  public hex_to_ascii
; Writes the hexdecimal ASCII representation of d0.l to the 11-byte buffer at a0
hex_to_ascii:
  movem.l d2/d3, -(a7) ; Save old values of d2 and d3 (callee preserved)
  move.b #'0', (a0)+
  move.b #'x', (a0)+
  move.b #0, d1
  move.w #28, d2
hex_to_ascii_loop:
  cmpi.w #0, d2
  beq.b hex_to_ascii_loop_done
  move.l d0, d3
  lsr.l d2, d3
  andi.l #$F, d3
  cmp.l #0, d3
  bne.b .1
  cmp.b #0, d1
  bne.b .1
  subi.w #4, d2
  bra.b hex_to_ascii_loop
.1:
  move.b #1, d1
  cmp.b #$A, d3
  blt.b .2
  add.b #('a' - $A), d3
  move.b d3, (a0)+
  bra.b .3
.2:
  add.b #'0', d3
  move.b d3, (a0)+
.3:
  subi.w #4, d2
  bra.b hex_to_ascii_loop
hex_to_ascii_loop_done:
  move.l d0, d3
  andi.l #$F, d3
  cmp.b #$A, d3
  blt.b .2
  add.b #('a' - $A), d3
  move.b d3, (a0)+
  bra.b .3
.2:
  add.b #'0', d3
  move.b d3, (a0)+
.3:
  move.b #0, (a0)
  movem.l (a7)+, d2/d3 ; Restore d2 and d3 (callee preserved)
  rts

; Compares the strings in a0 and a1
; Returns 0 in d0.b if identical
; Returns difference of first mismatching character in d0.b (s1-s2) if different
  public strcmp
strcmp:
strcmp_loop:
  move.b (a0), d0
  cmp.b (a1), d0
  bne.b strcmp_loop_done
  cmpi.b #0, (a0)
  bne.b .1
  move.b #0, d0
  rts
.1:
  adda.l #1, a0
  adda.l #1, a1
  bra.b strcmp_loop
strcmp_loop_done:
  move.b (a0), d0
  sub.b (a1), d0
  rts