;;
  ;;  spreadspace pic utils
  ;;
  ;;
  ;;  Copyright (C) 2011-2013 Christian Pointner <equinox@spreadspace.org>
  ;;
  ;;  This file is part of spreadspace pic utils.
  ;;
  ;;  spreadspace pic utils is free software: you can redistribute it and/or modify
  ;;  it under the terms of the GNU General Public License as published by
  ;;  the Free Software Foundation, either version 3 of the License, or
  ;;  any later version.
  ;;
  ;;  spreadspace pic utils is distributed in the hope that it will be useful,
  ;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
  ;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  ;;  GNU General Public License for more details.
  ;;
  ;;  You should have received a copy of the GNU General Public License
  ;;  along with spreadspace pic utils. If not, see <http://www.gnu.org/licenses/>.
  ;;

  org       .0
  bootmacro

  ;; -------------------------------------
  ;; goto user ISR
  org       .4
isr
  goto      ISRVECT

  ;; -------------------------------------
  ;; Bootloader (Generic Subroutines)
send_answer                     ; generic answer message, leave len of data in W
  addlw     .3
  movwf     combuff + .1
  decf      combuff + .1,w
  movwf     cnt
  movlw     combuff
  movwf     FSR
  clrf      csum
send_answer_next
  movf      INDF,w
  call      com_tx_byte
  incf      FSR,f
  decfsz    cnt,f
  goto      send_answer_next

  movf      csum,w
  call      com_tx_byte
  return

  ;; ------------------
ack_cmd                         ; short answers which only contain return code
  movwf     combuff + .2
  movlw     .1
  call      send_answer
  return