Added linux build steps (#366)

* refactored and added steps for linux

* libbpf build script for linux

* refactored headings

README.md

@@ -28,13 +28,7 @@ sure to properly check out the source code which requires properly initializing
 git submodule update --init --recursive
 ```
 
-## Building with CMake
-A build system for compiling and testing ubpf is generated for Windows, Linux and macOS platforms using [`cmake`](https://cmake.org/):
-
-```
-cmake -S . -B build -DUBPF_ENABLE_TESTS=true
-cmake --build build --config Debug
-```
+## Preparing system for build
 
 In order to prepare your system to successfully generate the build system using CMake, follow the platform-specific instructions below.
 
@@ -83,7 +77,19 @@ cmake -S . -B build -DUBPF_ENABLE_TESTS=true -DUBPF_ALTERNATE_LLVM_PATH=/opt/hom
 ```
 
 ### Linux
-TBD
+
+```bash
+./scripts/build-libbpf.sh
+```
+
+## Building with CMake
+
+A build system for compiling and testing ubpf is generated for Windows, Linux and macOS platforms using [`cmake`](https://cmake.org/):
+
+```
+cmake -S . -B build -DUBPF_ENABLE_TESTS=true
+cmake --build build --config Debug
+```
 
 ## Running the tests
 

scripts/build-libbpf.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/bash
+# Copyright (c) Microsoft Corporation
+# SPDX-License-Identifier: MIT
+
+git clone /~https://github.com/libbpf/libbpf.git
+if [ $? -ne 0 ]; then
+	echo "Could not clone the libbpf repository."
+	exit 1
+fi
+
+# Jump in to the src directory to do the actual build.
+cd libbpf/src
+
+make
+if [ $? -ne 0 ]; then
+	echo "Could not build libbpf source."
+	exit 1
+fi
+
+# Now that the build was successful, install the library (shared
+# object and header files) in a spot where FindLibBpf.cmake can
+# find it when it is being built.
+sudo PREFIX=/usr LIBDIR=/usr/lib/x86_64-linux-gnu/ make install
+exit 0