m1/tools/: xdltap and xdlfixes, to add taps to FPGA signals

m1/tools/xdlfixes

@@ -0,0 +1,78 @@
+#!/usr/bin/perl
+#
+# xdlfixes - Pro-process a Xilinx .xdl file such that xdl -xdl2ncd accepts it
+#
+# Written 2011 by Werner Almesberger
+# Copyright 2011 by Werner Almesberger
+#
+# This program 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 2 of the License, or
+# (at your option) any later version.
+#
+
+
+sub usage
+{
+	print STDERR "usage: $0 [infile]\n";
+	exit(1);
+}
+
+
+&usage if $ARGV[0] =~ /^-/;
+
+while (<>) {
+	#
+	# BUG: identifiers containing commas are generated by xdl -ncd2xdl
+	# but cannot be parsed by xdl -xdl2ncd. We therefore replace all the
+	# commas in identifiers with underscores.
+	#
+
+	$t = $_;
+	$s = "";
+	while ($t =~ /[^\\]"\S+"/) {
+		$s .= $`;
+		($q = $&) =~ y/,/_/;
+		$t = $';
+		$s .= $q;
+	}
+	$s .= $t;
+
+	#
+	# BUG: xdl -xdl2ncd does not seem to understand that inputs are not
+	# outputs. We have two choices here: define the output standard as
+	# "#OFF" or define it as "LVCMOS33".
+	#
+	# With "LVCMOS33", xdl will also insist on the slew rate and the drive
+	# strength.
+	#
+	# In any case, we end up with something the DRC of bitgen will reject.
+	# Luckily, bitgen has the option -d to turn off the DRC. It then
+	# cheerfully announces
+	#
+	#   ERROR:Bitgen - Could not find programming information for I/O
+	#   standard #OFF [...]
+  	#   The programming of the output buffers will not be correct.
+	#
+	# but the resulting mess appears to work regardless.
+	#
+
+	if ($_ =~ /^inst /) {
+		$s = $_;
+		while (!/;\s*$/) {
+			$_ = <>;
+			$s .= $_;
+		}
+#		$s =~ s/\bISTANDARD::LVCMOS33\b/$& OSTANDARD::LVCMOS33/;
+#		$s =~ s/\bISTANDARD::LVCMOS33\b/$& OSTANDARD::#OFF/;
+		$s =~ s/\bISTANDARD::LVCMOS33\b/$& OSTANDARD::#OFF/ unless
+		    $s =~ /\bOSTANDARD:/;
+#		$s =~ s/\bINBUF:/OUTBUF::#OFF $&/;
+#		if ($s =~ /\bISTANDARD::LVCMOS33\b/) {
+#			$s =~ s/\bSLEW::#OFF\b/SLEW::SLOW/g;
+#			$s =~ s/\bDRIVEATTRBOX::#OFF\b/DRIVEATTRBOX::12/g;
+#		}
+	}
+
+	print $s || die "write: $!";
+}