#/usr/bin/perl -w
#
# Generator of single S3 records for EEPROM branding
#
# author: Ned Konz <address@hidden>
# date: Fri Nov 18 11:56:20 PST 2005
# license: public domain
#
sub usage
{
	print STDERR "usage:
perl srecord.pl <start-address> <typeflags> <data> [...]
  where start-address is a C number literal (1234, 0x1234, or 01234)
  and typeflags is a string of one or more Perl pack() codes, including:
	c		1 byte integer
	v		unsigned short (2 byte) integer, little-endian
	V		unsigned long (4 byte) integer, little-endian
	H*		hex string of arbitrary length
  if data is '-' then number/hex string is read from stdin
";
}

# Main program
if ($#ARGV < 2)
{
	usage();
	exit(1);
}

our $startAddress = shift();
	$startAddress= oct($startAddress) if $startAddress =~ /^0/;

our $typeFlag = shift();

our @data = ();
foreach my $arg (@ARGV)
{
	if ($arg eq '-') { $arg = <STDIN>; }
	else { $arg = oct($arg) if $arg =~ /^0/; }
	push @data, $arg;
}

if ($type = ($typeFlag =~ m/[a-zA-Z]/))
{
	# first, pack both the data and start address
	my $packed = pack($typeFlag, @data);
	my $packedAddress = pack("V*", $startAddress);

	# so we can generate the checksum
	my $checksum = (~ unpack("%*A*", $packedAddress . $packed)) & 0xff;

	my $sLength = 5 + length($packed);

	printf("S3%02x%08x%s%02x\n", $sLength, $startAddress, unpack("H*", $packed), $checksum);
}
else
{
	usage();
	exit(2);
}