#!/usr/bin/perl
# 
# Copyright © 2015-2025 by Vincent Slyngstad
# 
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS LISTED ABOVE BE LIABLE
# FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
# 
# Except as contained in this notice, the names of the authors above
# shall not be used in advertising or otherwise to promote the sale, use
# or other dealings in this Software without prior written authorization
# from those authors.

#
# Convert a .SV file into a .BN file

# First, get the header information.

# JSW bits:
#    0-No 00000-01777
#    1-No 10000-11777
#    2-Reload
#    3-Less 8k
#   10-No pre CD
#   11-No pre USR

$half = 0;
sub getword {
  if ($half == 0) {
#   read(INPUT, $ccc, 3) || die "read: $! at ", tell(INPUT); # 3 bytes is two words.
    read(INPUT, $ccc, 3) || ($ccc = pack("CCC", 0, 0, 0)); # 3 bytes is two words.
    ($w1, $w2, $c3) = unpack("CCC", $ccc);
    $w1 += ($c3 & 0xF0) << 4;
    $w2 += ($c3 & 0x0F) << 8;
    $half = 1;
    return $w1;
  }
  $half = 0;
  return $w2;
}

$f = $ARGV[0];
open(INPUT, $f) || die "$f: $!";
binmode(INPUT);
@co = @pc = @fld = ();
# The first four words
$cs = 010000-&getword; # Core Segment Count (stored negative)
$sf = &getword; # Starting Field (062N3)
$sa = &getword; # Starting Address
$jsw = &getword; # JSW
# There are only descriptor slots for 62 core segments.
die "$f: Can't have $cs segments!\n" unless $cs && $cs < 63;
# Now, save each core segment doubleword.
for ($i = 0; $i < $cs; $i++) {
  push(@co, &getword); # Core Origin
  $pc = &getword;
  push(@pc, $pc >> 6); # Page Count
  push(@fld, ($pc >> 3) & 07); # Field to load
}
$cs--;
die "origin count $#co != $cs\n" unless $#co == $cs;
die "page count $#pc != $cs\n" unless $#pc == $cs;
die "field count $#fld != $cs\n" unless $#fld == $cs;
#warn "cs == $cs";
# At this point, we have parsed a seemingly valid header.
#
print "#!os8\n# $f";
#
# Now iterate over the various blocks and display them.
seek(INPUT, 3*256/2, 0) || die "seek: $!";
$pages = 0;
for ($i = 0; $i <= $cs; $i++) {
  $base = $fld[$i]*010000 + $co[$i];
  print "\n\n# Segment $i: $pc[$i] pages";
  $col = 9;
  # Load each page
#warn "Loading $pc[$i] pages\n";
  for ($j = 0; $j < $pc[$i]; $j++) {
#warn "Loading page $j from ", tell(INPUT);
#warn "got here $base";
    for ($k = 0; $k < 0200; $k++) {
      if (($col > 8) || ($base != $ma)) {
        printf "\n%05o)", $base;
        $col = 1;
        $ma = $base;
      }
      printf "%04o ", &getword;
      $col++;
      $base++;
      $ma++;
    }
    $pages++;
  }
  # If an odd number of pages, skip unused storage
  if ($pc[$i] & 0001) {
    for ($k = 0; $k < 0200; $k++) {
      &getword;
    }
    $pages++;
  }
}
print "\n";
# At this point we have displayed the loadable bits
# of the file.  Check that is actually all of the file.
# BUGBUG: TODO
$cruft = (-s INPUT) - 3*128*$pages;
if ($cruft > 0) {
  $cruft /= 3*128;
  print "# $cruft pages of overlays\n";
  $base = $ma = $cruft * 128;
  for ($i = 0; $i < $cruft; $i++) {
    for ($k = 0; $k < 0200; $k++) {
      if (($col > 8) || ($base != $ma)) {
        printf "\n%05o:", $base;
        $col = 1;
        $ma = $base;
      }
      printf "%04o ", &getword;
      $col++;
      $base++;
      $ma++;
    }
  }
  print "\n";
}
print "\n";
#
# Emit the JSW and Starting Address.
printf "# JSW %04o\n", $jsw;
printf "# START %05o\n", (($sf & 070) << 9) + $sa;
exit 0;