.text
.org 0x20

stev1:  .byte 15
stev2:  .byte 130

.align

.global _start
_start:

  adr   r0, stev2
  ldrsb r2, [r0]

  adr   r0, stev1
  ldrsb r1, [r0]

  add   r1, r2

  str   r1, [r0]