# Register usage:
# s2: data fd
# s3: number of bytes read
# s4: number of bytes parsed
# s5: jump destination for parsing next character
# s6: character
# s7: pointer to tree node

  addi s3, a0, 0 # s3: number of bytes read
  addi s4, zero, 0 # s4: number of bytes parsed

on_eof:

on_eof: