part of configure.ac that determines addressing mode

configure.ac

if [[ "x$WANT_NATIVE_M68K" = "xyes" ]]; then
  ADDRESSING_MODE="real"
else
  ADDRESSING_MODE=""
  AC_MSG_CHECKING([for the addressing mode to use])
  for am in $ADDRESSING_TEST_ORDER; do
    case $am in
    real)
      dnl Requires ability to mmap() Low Memory globals
      if [[ "x$ac_cv_can_map_lm$ac_cv_pagezero_hack" = "xnono" ]]; then
        continue
      fi   
      dnl Requires VOSF screen updates
      if [[ "x$CAN_VOSF" = "xno" ]]; then
        continue
      fi   
      dnl Real addressing will probably work.
      ADDRESSING_MODE="real"
      WANT_VOSF=yes dnl we can use VOSF and we need it actually
      DEFINES="$DEFINES -DREAL_ADDRESSING"
      if [[ "x$ac_cv_pagezero_hack" = "xyes" ]]; then
        BLESS=Darwin/lowmem
        LDFLAGS="$LDFLAGS -pagezero_size 0x2000"
      fi   
      break
      ;;   
    direct)
      dnl Requires VOSF screen updates
      if [[ "x$CAN_VOSF" = "xyes" ]]; then
        ADDRESSING_MODE="direct"
        WANT_VOSF=yes dnl we can use VOSF and we need it actually
        DEFINES="$DEFINES -DDIRECT_ADDRESSING"
        break
      fi   
      ;;   
    banks)
      dnl Default addressing mode
      ADDRESSING_MODE="memory banks"
      break
      ;;   
    *)   
      AC_MSG_ERROR([Internal configure.in script error for $am addressing mode])
    esac
  done