[win32] Add build scripts

This patch adds a couple of scripts that can be used for
building Ceph for Windows along with its dependencies.

For now, we're going to cross compile it using mingw.
It's supposed to run on Ubuntu (feel free to update
the command that's installing some of the dependencies
within win32_deps_build.sh if you're interested in other
distros).

This commit also adds a short readme, describing the focus of
the Windows porting effort, the building process and the current
status.

Signed-off-by: Lucian Petrut <lpetrut@cloudbasesolutions.com>
Signed-off-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/README.windows.rst b/README.windows.rst
new file mode 100644
index 00000000000..f6a0ee8a9ef
--- /dev/null
+++ b/README.windows.rst
@@ -0,0 +1,50 @@
+About
+-----
+
+Ceph Windows support is currently a work in progress. For now, the main focus
+is the client side, allowing Windows hosts to consume rados, rbd and cephfs
+resources.
+
+Building
+--------
+
+At the moment, mingw gcc is the only supported compiler for building ceph
+components for Windows. Support for msvc and clang will be added soon.
+
+`win32_build.sh`_ can be used for cross compiling Ceph and its dependencies.
+It may be called from a Linux environment, including Windows Subsystem for
+Linux. MSYS2 and CygWin may also work but those weren't tested.
+
+.. _win32_build.sh: win32_build.sh
+
+The script accepts the following flags:
+
+============  ===============================  ===============================
+Flag          Description                      Default value
+============  ===============================  ===============================
+CEPH_DIR      The Ceph source code directory.  The same as the script.
+BUILD_DIR     The directory where the          $CEPH_DIR/build
+              generated artifacts will be
+              placed.
+DEPS_DIR      The directory where the Ceph     $CEPH_DIR/build.deps
+              dependencies will be built.
+NUM_WORKERS   The number of workers to use     The number of vcpus
+              when building Ceph.              available
+NINJA_BUILD   Use Ninja instead of make.
+CLEAN_BUILD   Clean the build directory.
+SKIP_BUILD    Run cmake without actually
+              performing the build.
+============  ===============================  ===============================
+
+Current status
+--------------
+
+The rados and rbd binaries and libs compile successfully and can be used on
+Windows, successfully connecting to the cluster and consuming pools.
+
+The libraries have to be built statically at the moment. The reason is that
+there are a few circular library dependencies or unspecified dependencies,
+which isn't supported when building DLLs. This mostly affects ``cls`` libraries.
+
+A significant number of tests from the ``tests`` directory have been port,
+providing adequate coverage.