--- a/usr/src/pkgdefs/SUNWrmodr/i.bootenvrc	Fri Apr 06 15:31:12 2007 -0700
+++ b/usr/src/pkgdefs/SUNWrmodr/i.bootenvrc	Fri Apr 06 15:57:19 2007 -0700
@@ -3,9 +3,8 @@
 # CDDL HEADER START
 #
 # The contents of this file are subject to the terms of the
-# Common Development and Distribution License, Version 1.0 only
-# (the "License").  You may not use this file except in compliance
-# with the License.
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
 #
 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 # or http://www.opensolaris.org/os/licensing.
@@ -23,7 +22,7 @@
 #
 #ident	"%Z%%M%	%I%	%E% SMI"
 #
-# Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
 while read src dest
@@ -31,6 +30,8 @@
 	if [ ! -f $dest ] ; then
 		# Initial installation
 		cp $src $dest
+		# Enable pci-renumber-buses property for initial install
+		echo setprop pci-renumber-buses 1 >> $dest
 	else
 		#
 		# Preserve the installed version of
@@ -92,7 +93,34 @@
 				echo $line >> $merge
 			fi
 		done
-		
+
+		#
+		# Make sure the merged file has a pci-renumber-buses property.
+		# If $dest doesn't already have the property, add it to the
+		# merged file using the following rule:
+		# - if on a Sun Blade x8400, add "pci-renumber-buses=1"
+		# - on all other systems, add "pci-renumber-buses=0"
+		#
+		/usr/bin/nawk '{print $2}' $dest | \
+		    grep -w pci-renumber-buses > /dev/null
+		if [ $? != 0 ] ; then
+			# smbios parameters
+			smtype=SMB_TYPE_BASEBOARD
+			name="Sun Blade x8400 Server Module"
+			#
+			# if smbios fails, we're not on an x8400, so it's
+			# the same as grep not finding the x8400 ID
+			#
+			(/usr/sbin/smbios -t $smtype | \
+			    grep "$name") > /dev/null 2>&1
+			if [ $? != 0 ] ; then
+				val="0"
+			else
+				val="1"
+			fi
+			echo setprop pci-renumber-buses $val >> $merge
+		fi
+
 		#
 		# copy the merged file to $dest
 		#

--- a/usr/src/uts/intel/io/pci/pci_boot.c	Fri Apr 06 15:31:12 2007 -0700
+++ b/usr/src/uts/intel/io/pci/pci_boot.c	Fri Apr 06 15:57:19 2007 -0700
@@ -98,7 +98,7 @@
 
 extern int pci_slot_names_prop(int, char *, int);
 
-/* set non-zero to force PCI peer-bus renumbering */
+/* set to 1 to force PCI peer-bus renumbering, -1 to prevent it */
 int pci_bus_always_renumber = 0;
 
 /* get the subordinate bus # for a root/peer bus */
@@ -289,21 +289,35 @@
 static int
 pci_bus_renumber()
 {
-	ACPI_TABLE_HEADER *fadt;
+	char *bus_prop;
+	long val;
 
-	if (pci_bus_always_renumber)
+	/* allow over-ride via patchable variable */
+	if (pci_bus_always_renumber > 0)
 		return (1);
-
-	/* get the FADT */
-	if (AcpiGetFirmwareTable(FADT_SIG, 1, ACPI_LOGICAL_ADDRESSING,
-	    (ACPI_TABLE_HEADER **)&fadt) != AE_OK)
+	else if (pci_bus_always_renumber < 0)
 		return (0);
 
-	/* compare OEM Table ID to "SUNm31" */
-	if (strncmp("SUNm31", fadt->OemId, 6))
-		return (0);
-	else
-		return (1);
+	/*
+	 * Get the "pci-renumber-buses" boot property
+	 * This property is set-up during installation;
+	 * upgraded systems disable re-numbering to avoid the
+	 * complication of changing physical device paths.
+	 *
+	 * If the "pci-renumber-buses" property is not found,
+	 * this suggests an incomplete BFU or failure during
+	 * upgrade.  In either case, default to "don't renumber"
+	 * so that a botched BFU/upgrade doesn't render a system
+	 * unbootable.
+	 */
+	val = 0;
+	if (ddi_prop_lookup_string(DDI_DEV_T_ANY, ddi_root_node(),
+	    DDI_PROP_DONTPASS, "pci-renumber-buses", &bus_prop) ==
+	    DDI_PROP_SUCCESS) {
+		(void) ddi_strtol(bus_prop, NULL, 0, &val);
+		ddi_prop_free(bus_prop);
+	}
+	return (val);
 }
 
 /*
@@ -321,11 +335,6 @@
 	int pci_regs[] = {0, 0, 0};
 	int	i, root_addr = 0;
 
-	/*
-	 * Currently, we only enable the re-numbering on specific
-	 * Sun machines; this is a work-around for the more complicated
-	 * issue of upgrade changing physical device paths
-	 */
 	if (!pci_bus_renumber())
 		return;