README_BUILD.md: update with a few settings from cmake files

Document the build instructions from the options that were in the cmake
files.

Signed-off-by: Robin Getz <[email protected]>

README_BUILD.md

@@ -34,24 +34,28 @@ analog@precision:~$ cd libiio
 ## Configure & Build
 
 when configuring libiio with cmake, there are a few optional settings that you can use to control the build.
+The recommendation is to leave things to the default.
+
+Cmake Options          | Default | Target | Description                                    |
+---------------------- | ------- | -------| ---------------------------------------------- |
+`BUILD_SHARED_LIBS`    |  ON |        All | Build shared libraries            |
+`PYTHON_BINDINGS`      | OFF |        All | Install PYTHON bindings                            |
+`WITH_TESTS`           |  ON |        All | Build the test programs (iio-utils)                |
+`WITH_EXAMPLES`        | OFF |        All | Build the example programs                         |
+`NO_THREADS`           | OFF |        All | Disable multi-threading support |
+`CSHARP_BINDINGS`      | OFF |    Windows | Install C# bindings                                |
+`CMAKE_INSTALL_PREFIX` | `/usr` |   Linux | default install path |
+`ENABLE_PACKAGING`     | OFF | Linux, MaC | Create .deb/.rpm or .tar.gz packages via 'make package' |
+`WITH_DOC`             | OFF |      Linux | Generate documentation with Doxygen and Sphinx     |
+`WITH_MAN`             | OFF |      Linux | Generate and install man pages                     |
+`INSTALL_UDEV_RULE`    |  ON |      Linux | Install a Linux udev rule for detection of USB devices |
+`UDEV_RULES_INSTALL_DIR` | /lib/udev/rules.d |    Linux | default install path for udev rules |
+`WITH_LOCAL_CONFIG`    |  ON |      Linux | Read local context attributes from /etc/libiio.ini |
+`WITH_HWMON`           | OFF |      Linux | Add compatibility with the hwmon subsystem         |
+`WITH_GCOV`            | OFF |      Linux | Build with gcov profiling flags |
+`OSX_FRAMEWORK`        |  ON |        Mac | OS X frameworks provide the interfaces you need to write software for Mac. |
+`OSX_PACKAGE`          |  ON |        Mac | Create a OSX package for installation on local and other machines |
 
-Cmake Options       | Default | Description                                    |
-------------------- | ------- | ---------------------------------------------- |
-`BUILD_SHARED_LIBS`    |  ON | Build shared libraries  |
-`CMAKE_INSTALL_PREFIX` | `/usr` | default install path |
-`ENABLE_PACKAGING`     | OFF  | Create .deb/.rpm or .tar.gz packages via 'make package' |
-`CSHARP_BINDINGS`   | OFF | Install C# bindings                                |
-`PYTHON_BINDINGS`   | OFF | Install PYTHON bindings                            |
-`WITH_DOC`          | OFF | Generate documentation with Doxygen and Sphinx     |
-`WITH_MAN`          | OFF | Generate and install man pages                     |
-`WITH_TESTS`        |  ON | Build the test programs (iio-utils)                |
-`INSTALL_UDEV_RULE` |  ON | Install a Linux udev rule for detection of USB devices |
-`UDEV_RULES_INSTALL_DIR` | /lib/udev/rules.d | default install path for udev rules |
-`WITH_EXAMPLES`     | OFF | Build the example programs                         |
-`WITH_LOCAL_CONFIG` |  ON | Read local context attributes from /etc/libiio.ini |
-`WITH_HWMON`        | OFF | Add compatibility with the hwmon subsystem         |
-`NO_THREADS`        | OFF | Disable multi-threading support |
-`WITH_GCOV`         | OFF | Build with gcov profiling flags |
 
 Which backends the library supports is dependent on the build system, but can be overridden.
 (If cmake finds libusb, it will use it, unless turned off manually)