=== modified file 'bin/usb-creator-helper'
--- bin/usb-creator-helper	2014-09-02 20:12:12 +0000
+++ bin/usb-creator-helper	2015-02-25 07:51:13 +0000
@@ -190,17 +190,45 @@
                    'bs=512', 'count=62', 'seek=1', 'conv=sync'])
         else:
             if syslinux_legacy and find_on_path('syslinux-legacy'):
+                syslinux_var = "syslinux-legacy"
                 syslinux_exe = "syslinux-legacy"
                 syslinux_bin = "/usr/lib/syslinux-legacy/mbr.bin"
             else:
+                syslinux_var = "syslinux"
                 syslinux_exe = "syslinux"
                 syslinux_bin = "/usr/lib/syslinux/mbr/mbr.bin"
                 if not os.path.exists(syslinux_bin):
                     syslinux_bin = "/usr/lib/syslinux/mbr.bin"
+            squashfs_mnt = ''
+            target_mounts = obj.get_filesystem().get_cached_property('MountPoints').get_bytestring_array()
+            if len(target_mounts) > 0:
+                target_mnt = target_mounts[0]
+                squashfs_img = os.path.join(target_mnt, 'casper',
+                                            'filesystem.squashfs')
+                if os.path.exists(squashfs_img):
+                    # Mount the squashfs so we are possible to install
+                    # syslinux & mbr.bin from it.
+                    squashfs_mnt = self.MountISO(squashfs_img)
+            if squashfs_mnt:
+                for mbrbin in [
+                        os.path.join(squashfs_mnt, 'usr', 'lib',
+                                     syslinux_var, 'mbr.bin'),
+                        os.path.join(squashfs_mnt, 'usr', 'lib',
+                                     syslinux_var, 'mbr', 'mbr.bin'),
+                        os.path.join(squashfs_mnt, 'usr', 'lib',
+                                     syslinux_var.upper(), 'mbr.bin'),
+                        ]:
+                    if os.path.exists(mbrbin):
+                        syslinux_exe = os.path.join(squashfs_mnt, 'usr',
+                                                    'bin', syslinux_var)
+                        syslinux_bin = mbrbin
+                        break
             popen([syslinux_exe, '-f', device])
             # Write the syslinux MBR.
             popen(['dd', 'if=%s' % syslinux_bin, 'of=%s' % parent_file,
                    'bs=446', 'count=1', 'conv=sync'])
+            if squashfs_mnt:
+                self.UnmountFile(squashfs_mnt)
 
         part = obj.get_partition()
         if part: