Update README.md

README.md

-# alarm
+# Alarm
 Elettra alarm-handler Tango device
 
 
-## building
-git clone http://github.com/ELETTRA-SincrotroneTrieste/makefiles.git
+## Building and Installation
 
-git clone http://github.com/ELETTRA-SincrotroneTrieste/alarm-handler.git
+In its simplest form, clone the repository and assuming a standard install for all dependencies:
 
-cd alarm-handler
+```
+mkdir build
+cd build
+cmake ../
+make
+make install
+```
+
+### pkg-config Settings
+
+The build system uses pkg-config to find some dependencies, for example Tango. If Tango is not installed to a standard location, set PKG_CONFIG_PATH, i.e.
+
+```bash
+export PKG_CONFIG_PATH=/non/standard/tango/install/location
+...
+cmake ../
+...
+```
+
+The pkg-config path can also be set with the cmake argument CMAKE_PREFIX_PATH. This can be set on the command line at configuration time, i.e.:
+
+```bash
+...
+cmake -DCMAKE_PREFIX_PATH=/non/standard/tango/install/location ../
+...
+```
+
+### Project Flags
 
+| Flag | Setting | Default | Description |
+|------|-----|-----|-----|
+| BUILD_TESTE | ON/OFF | OFF | Build test devices under test directory |
+
+### Standard CMake Flags
+
+The build system is CMake therefore standard CMake flags can be used to influence the build and installation process. The following is a list of common useful CMake flags and their use:
+
+| Flag | Use |
+|------|-----|
+| CMAKE_INSTALL_PREFIX | Standard CMake flag to modify the install prefix. |
+| CMAKE_INCLUDE_PATH | Standard CMake flag to add include paths to the search path. |
+| CMAKE_LIBRARY_PATH | Standard CMake flag to add paths to the library search path |
+
+
+## Legacy Building
+
+Using Elettra makefiles, clone both alarm-handler and makefile repositories, then call make:
+
+```bash
+git clone http://gitlab.elettra.eu/cd/ds/makefiles.git
+git clone http://gitlab.elettra.eu/cs/ds/alarm-handler.git
+cd alarm-handler
 make
+```