diff -r 60b6e820abe5 README
--- a/README	Fri Oct 28 19:01:46 2016 -0400
+++ b/README	Sat Oct 29 12:00:22 2016 +0200
@@ -85,6 +85,30 @@
 performance gains.
 
 
+Cross Compiling on unix
+-----------------------
+
+The cross-compilation of Python requires a natively installed python to run
+Python scripts at multiple stages in the build process. The path to this native
+python must be set in the $PATH environment variable and it must have the same
+package version as the Python source being cross-built (for example python3.6).
+
+One way to ensure that the previous rule is followed is to build the native
+python from the same source first. For example:
+
+    mkdir python-native build install
+    cd python-native
+    /path/to/source/configure && make
+    export PATH=$(pwd):$PATH
+    cd ../build
+    /path/to/source/configure --host=<triplet> --build=<triplet> \
+        ac_cv_file__dev_ptmx=no ac_cv_file__dev_ptc=no \
+        && make DESTDIR=../install install
+
+If the target Python can use /dev/ptmx or /dev/ptc to implement os.openpty(),
+set the corresponding argument to "yes".
+
+
 What's New
 ----------