[util] Add mergerom.pl

This utility is required as a workaround for legal restrictions on
including GPL and non-GPL code within the same expansion ROM image.

While this is not encouraged, we are prepared to accept that
concatenation of ROM images and updating of the ROM header data
structures can be classed as "mere aggregation" within the terms of
the GPL.

If in any doubt, assume that you cannot include GPL and non-GPL code
within the same expansion ROM image.  Contact the Etherboot team for
clarification on your specific circumstances.

src/util/mergerom.pl

+#!/usr/bin/perl -w
+#
+# Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
+#
+# 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 any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+use strict;
+use warnings;
+
+use FindBin;
+use lib "$FindBin::Bin";
+use Option::ROM qw ( :all );
+
+my @romfiles = @ARGV;
+my @roms = map { my $rom = new Option::ROM; $rom->load($_); $rom } @romfiles;
+
+my $baserom = shift @roms;
+my $offset = $baserom->length;
+
+foreach my $rom ( @roms ) {
+
+  # Update base length
+  $baserom->{length} += $rom->{length};
+
+  # Update PCI header, if present in both
+  my $baserom_pci = $baserom->pci_header;
+  my $rom_pci = $rom->pci_header;
+  if ( $baserom_pci && $rom_pci ) {
+
+    # Update PCI lengths
+    $baserom_pci->{image_length} += $rom_pci->{image_length};
+    if ( exists $baserom_pci->{runtime_length} ) {
+      if ( exists $rom_pci->{runtime_length} ) {
+	$baserom_pci->{runtime_length} += $rom_pci->{runtime_length};
+      } else {
+	$baserom_pci->{runtime_length} += $rom_pci->{image_length};
+      }
+    }
+
+    # Merge CLP entry point
+    if ( exists ( $baserom_pci->{clp_entry} ) &&
+	 exists ( $rom_pci->{clp_entry} ) ) {
+      $baserom_pci->{clp_entry} = ( $offset + $rom_pci->{clp_entry} )
+	  if $rom_pci->{clp_entry};
+    }
+  }
+
+  # Update PnP header, if present in both
+  my $baserom_pnp = $baserom->pnp_header;
+  my $rom_pnp = $rom->pnp_header;
+  if ( $baserom_pnp && $rom_pnp ) {
+    $baserom_pnp->{bcv} = ( $offset + $rom_pnp->{bcv} ) if $rom_pnp->{bcv};
+    $baserom_pnp->{bdv} = ( $offset + $rom_pnp->{bdv} ) if $rom_pnp->{bdv};
+    $baserom_pnp->{bev} = ( $offset + $rom_pnp->{bev} ) if $rom_pnp->{bev};
+  }
+
+  # Fix checksum for this ROM segment
+  $rom->fix_checksum();
+
+  $offset += $rom->length;
+}
+
+$baserom->pnp_header->fix_checksum() if $baserom->pnp_header;
+$baserom->fix_checksum();
+$baserom->save ( "-" );
+foreach my $rom ( @roms ) {
+  $rom->save ( "-" );
+}