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

m1/tools/README

@@ -20,3 +20,34 @@ You need to have fjmem.bit somwehere. It searches for it under
 $HOME/.qi/milkymist/, where reflash_m1.sh caches it. You can also
 specify the location directly by setting the environment variable
 FJMEM_BIT.
+
+
+xdltap - Route nets from inside the FPGA to I/O pads
+====================================================
+
+xdltap adds routes from signals inside the FPGA to I/O pads. It
+does this by converting the .ncd file generated by synthesis 
+
+xdltap signal=output ... [xdl-file]
+
+The path to the signal to be tapped has to be fully qualified.
+Note that not all signals are listed in the .pcf file. Some may
+only show up in .xdl
+
+The output is the name of a global net that has to be connected
+to an input (!) pad.
+
+Signal names containing < and > can be written with { and }, to
+avoid extra escaping for the shell.
+
+Since xdl chokes on its own .xdl files, xdlfixes applies a number
+of ugly hacks to either avoid errors or to propagate them to a
+later stage, where they can be ignored.
+
+Example:
+
+map ... foo.ngd			# generates foo.ncd
+xdl -ncd2xdl foo.ncd		# generates foo.xdl
+xdltap usb/sie/rx_pending=exp{8} foo.xdl | xdlfixes >foo-dbg.xdl
+xdl -xdl2ncd foo-dbg.xdl	# generates foo-dbg.ncd
+par ... foo-dbg.ncd ...

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: $!";
+}

m1/tools/xdltap

@@ -0,0 +1,117 @@
+#!/usr/bin/perl
+#
+# xdltap - Route nets from inside the FPGA to I/O pads
+#
+# 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 change
+{
+	local ($s, $v, $from, $to) = @_;
+
+	if (defined $from) {
+		die "${v}::$from not found in\n$s"
+		    unless $s =~ /\b${v}::$from/;
+		return "$`${v}::$to$'";
+	} else {
+		die "${v}::... not found in\n$s"
+		    unless $s =~ /\b${v}::\S+/;
+		return "$`${v}::$to$'";
+	}
+}
+
+
+sub change_var
+{
+	local ($s, $from, $to) = @_;
+
+	die "${from}::... not found in\n$s"
+	    unless $s =~ /\b${from}::/;
+	return "$`${to}::$'";
+}
+
+
+sub reassign
+{
+	local ($s, $from, $to) = @_;
+
+	$s =~ s/\bINBUF:${to}_IBUF:/OUTBUF:${to}_OBUF:/ ||
+	    die "INBUF:${to}_IBUF: not found in\n$s";
+	$s =~ s/\bPULL:${to}_PULLDOWN:// ||
+	    die "PULL:${to}_PULLDOWN: not found in\n$s";
+	$s =~ s/\bIMUX:[^:]+:I/IMUX::#OFF/ ||
+	    die "IMUX:...:I not found in\n$s";
+	$s = &change($s, "BYPASS_MUX", "I", "#OFF");
+	$s = &change($s, "DRIVEATTRBOX", "#OFF", "12");
+	$s = &change($s, "OUSED", "#OFF", "0");
+	$s = &change($s, "PULLTYPE", "PULLDOWN", "#OFF");
+	$s = &change($s, "SLEW", "#OFF", "SLOW");
+	$s = &change($s, "SUSPEND", "#OFF", "3STATE");
+	$s = &change_var($s, "ISTANDARD", "OSTANDARD");
+	return $s;
+}
+
+
+sub usage
+{
+	print STDERR <<"END"
+usage: $0 [net=output ...] [file]
+
+  net     fully qualified path to the signal in question, e.g.,
+          usb/sie/rx_pending
+  output  name of the (input) connected to the output pin, e.g., exp<8>
+
+For better shell compatibility, { and } can be used instead of < and >
+END
+	    ;
+	exit(1);
+}
+
+
+&usage if $ARGV[0] =~ /^-/;
+
+while ($ARGV[0] =~ /=/) {
+	($from, $to) = ($`, $');
+	$to =~ tr/{}/<>/;
+	$from{$from} = $to;
+	$to{$to} = $from;
+	$need{$from} = $need{$to} = 1;
+	shift @ARGV;
+}
+
+while (<>) {
+	if ($_ =~ /^inst "([^"]*)"/ && defined $to{$1}) {
+		die "" unless $need{$1};
+		delete $need{$1};
+		$s = $_;
+		while (!/;\s*$/) {
+			$_ = <>;
+			$s .= $_;
+		}
+		print &reassign($s, $to{$1}, $1) || die "write: $!";
+		next;
+	}
+	if (/^net "([^"]*)_IBUF"/ && defined $to{$1}) {
+		next if /;\s*$/;
+		while (<>) {
+			last if /;\s*$/;
+		}
+		next;
+	}
+	print || die "write: $!";
+	if (/^net "([^"]*)"/) {
+		next unless defined $from{$1};
+		die unless $need{$1};
+		delete $need{$1};
+		print "  inpin \"$from{$1}\" O,\n" || die "write: $!";
+	}
+}
+
+die "not found: ".join(", ", sort keys %need) if %need;