x86: fix platform_export_bootpart() for Xen virtual disks

Virtual disk devices in a Xen virtual machine (DomU) can be /dev/xvda,
/dev/xvdb and so on with partitions like /dev/xdva1. Devices named like
this where not considered before. This resulted in a non working
sysupgrade, because the boot partition could not be found.

Signed-off-by: Alexander Dahl <alex@netz39.de>
Suggested-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 49190

target/linux/x86/base-files/lib/upgrade/platform.sh

@@ -17,7 +17,7 @@ platform_export_bootpart() {
 			PARTUUID=[a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]-02)
 				uuid="${disk#PARTUUID=}"
 				uuid="${uuid%-02}"
-				for disk in /dev/[hsv]d[a-z]; do
+				for disk in /dev/[hsv]d[a-z] /dev/xvd[a-z]; do
 					set -- $(dd if=$disk bs=1 skip=440 count=4 2>/dev/null | hexdump -v -e '4/1 "%02x "')
 					if [ "$4$3$2$1" = "$uuid" ]; then
 						export BOOTPART="${disk}1"