OTP-8449 Documentation improvements.

          The most important "readme" files now use Markdown notation. HTML
          versions of these files are now also automatically generated and
          included in the HTML documentation.

          - Building and Installing Erlang/OTP - $ERL_TOP/INSTALL.md
          (previously known as $ERL_TOP/README).

          - Cross Compiling Erlang/OTP - $ERL_TOP/INSTALL-CROSS.md.

          - How to Build Erlang/OTP on Windows - $ERL_TOP/INSTALL-WIN32.md
          (previously known as $ERL_TOP/README.win32).

1 files changed, 8 insertions, 1 deletions

diff --git a/xcomp/README.md b/xcomp/README.md
index bc2696c046..9f638f46d7 100644
--- a/xcomp/README.md
+++ b/xcomp/README.md
@@ -14,7 +14,7 @@ compile Erlang/OTP. Before reading this document you should read the
 general. `$ERL_TOP` is the top directory in the source tree.
 
 `otp_build` Versus `configure`/`make`
-------------------------------------
+-------------------------------------
 
 Building Erlang/OTP can be done either by using the `$ERL_TOP/otp_build`
 script, or by invoking `$ERL_TOP/configure` and `make` directly. Building using
@@ -111,6 +111,13 @@ has to be provided in the `$PATH`. The Erlang/OTP for the target system will
 be built using this Erlang system, together with the cross compilation tools
 provided.
 
+If you want to build the documentation out of the same source tree as you are
+cross compiling in, you currently need a full Erlang/OTP system of the same
+release as the one being built for the build machine. If this is the case,
+build and install one for the build machine (or use one already built) and add
+it to the `$PATH` before cross building, and building the documentation. See
+[`$ERL_TOP/INSTALL.md`] [1] for information on building the documentation.
+
 If you want to build using a compatible Erlang/OTP system in the `$PATH`,
 jump to (3).