#!/usr/bin/perl
#reads EEPROM definition file and writes Intel hex format.
#Copyright: Owen Duffy 2011. All rights reserved.
use JSON;
#use Data::Dumper;

$id='$Id: j2h.pl 686 2011-12-24 22:25:33Z owen $';
$ctr=0;
$offs=0;
$buff0;
@r=(0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15);

sub rev{
  my ($s)=@_;
  my $i;
  $out='';
  for($i=length($s)-1;$i>=0;$i--){
    $out=$out.sprintf("%01X",$r[hex(substr($s,$i,1))]);
    }
  $out;
  }

sub dobyte{
  ($buff0[$ctr++])=@_;
  if($ctr==16){inforec()}
  }

sub inforec{
  my $i;
  my $buff1='';
  my $chksum=0;
  my $rectype=0;

  for($i=0;$i<$ctr;$i++){$buff1.=sprintf("%02X",$buff0[$i])}
  $buff1=sprintf("%02X%04X%02X",length($buff1)/2,$offs,$rectype).$buff1;
  $chksum+=$_ for unpack('C*', pack("H*",$buff1));
	printf(":%s%02X\n",$buff1,(~($chksum)+1)&0xff);
	$offs+=$ctr;
	$ctr=0;
} 

my $regsitem=0;
my $buff2=''; 

#strip leading comments
while(<>){if(m/^\s*?\{/m){last}} #skip lines until leading brace
#now slurp the rest
{local $/;@json=$_.<>;}
#decode it  
$cfg=decode_json(@json);

#now traverse the config data
$revflag=($cfg->{'rbo'} eq 'R');
for($j=0;$j<($#{$cfg->{'regs'}}+1);$j++){
  $buff3='';
  $regslen[$j]=0;
  for($i=0;$i<($#{$cfg->{'regs'}[$j]}+1);$i++){
  $yy=($#{$cfg->{'regs'}[$j]}+1);
    $str=$cfg->{'regs'}[$j][$i];
    if(length($str)%2){$str='0'.$str};
    if($revflag){$str=rev($str);}
    $reglen=int(length($str)/2);
    $buff3.=sprintf("%02X%s",$reglen,$str);
    $regslen[$j]+=$reglen+1;
	  }
    $buff2.=sprintf("%02X%s",$regslen[$j]).$buff3;
  }

$off=0;
$buff1='';
#build rec
$buff1.=$cfg->{'ver'};
$off+=1;
$buff1.=$cfg->{'options'};
$off+=2;
#built the toc
my $nregsets=$#{$cfg->{'regs'}}+1;
$buff1.=sprintf("%02X",$nregsets*2);
$off+=1;
$off+=$nregsets*2; #add in toc length
for($j=0;$j<$nregsets;$j++){
#  $len=$regslen[$j];
  $buff1.=sprintf("%02X%02X",$off&0xff,$off>>8);
  $off+=$regslen[$j]+1;
  }
$buff1.=$buff2;

for $ch (unpack('C*', pack('H*',$buff1))){dobyte($ch)}
if($ctr>0){inforec} #residual
printf(":00000001FF\n"); #EOF rec