Simplify use from outside the toplevel Makefile.
: ${HARCH:=$(uname -i)}
: ${NETBSD_RELEASE:=$(basename $(cd $(dirname $0) && pwd) | sed 's/netbsd-\([0-9]\+\.[0-9]\+\).*/\1/')}
: ${NETBSD_VERSION:=$(basename $(cd $(dirname $0) && pwd) | sed 's/netbsd-\([0-9]\+\.[0-9]\+.*\)-xen.*/\1/')}
+: ${TOPDIR:=$(cd $(dirname $0) && pwd | sed 's/\(netbsd-[0-9]\+\.[0-9]\+.*-xen[^/]*\)/\1/')}
TOOLDIR="$TOPDIR/../netbsd-${NETBSD_RELEASE}-tools/$HOS-$HARCH"; export TOOLDIR
: ${HARCH:=$(uname -i)}
: ${NETBSD_RELEASE:=$(basename $(cd $(dirname $0) && pwd) | sed 's/netbsd-\([0-9]\+\.[0-9]\+\).*/\1/')}
: ${NETBSD_VERSION:=$(basename $(cd $(dirname $0) && pwd) | sed 's/netbsd-\([0-9]\+\.[0-9]\+.*\)-xen.*/\1/')}
+: ${TOPDIR:=$(cd $(dirname $0) && pwd | sed 's/\(netbsd-[0-9]\+\.[0-9]\+.*-xen[^/]*\)/\1/')}
NETBSDSRCDIR="$TOPDIR"; export NETBSDSRCDIR
DESTDIR="$TOPDIR/root"; export DESTDIR