fix: README -> README.md

ta6ob/s/Mf-cross

@@ -0,0 +1,44 @@
+# Mf-cross
+# Copyright 1984-2017 Cisco Systems, Inc.
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+# http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Usage: make -f Mf-cross m=host xm=target, e.g.:
+#    make -f Mf-cross m=i3le xm=i3osx
+# to cross-compile to i3osx from i3le
+
+what = all examples
+base = ../..
+
+xdoit:	xboot
+
+include Mf-${xm}
+
+Scheme=$(base)/bin/${m}/scheme
+export SCHEMEHEAPDIRS=$(base)/boot/${m}
+o = 2
+i = t
+d = 3
+
+xpatch = xpatch
+xpatchobj = ${patchobj}
+
+xboot: ${xpatch}
+	$(MAKE) -f Mf-${xm} ${what} m=${xm} patchfile=${xpatch} Scheme="${Scheme}" SCHEMEHEAPDIRS=${SCHEMEHEAPDIRS}
+
+${xpatch}: ${xpatchobj}
+	cat ${xpatchobj} > ${xpatch}
+
+x$(xm).$(m):
+	$(MAKE) -f Mf-cross m=$(m) xm=$(xm) i=f o=3 d=0 xpatch
+	mv xpatch x$(xm).$(m)