Directory Structure :
---------------------
1. l2/build/ : contains files required to compile the code
   a. common : contains individual module's makefile
   b. odu    : contains main makefile to generate an executable binary
   c. scripts: contains scripts for logging
   d. o1     : contains main makefile to generate an executable binary

2. l2/docs/  : contains README and other configuration files for building docs
	
3. l2/src/ : contains layer specific source code
   a. 5gnrmac  : MAC source code
   b. 5gnrrlc  : RLC source code
   c. cm       : common, environment and interface files
   d. cu_stub  : Stub code for CU
   e. du_app   : DU application and F1 code 
   f. mt       : wrapper functions over OS
   g. phy_stub : Stub code for Physical layer
   h. rlog     : logging module
   i. o1       : o1 module


Pre-requisite for Compilation :
-------------------------------
1. Linux 32-bit/64-bit machine
2. GCC version 4.6.3 and above
3. Install LKSCTP
   a. On Ubuntu : sudo apt-get install -y libsctp-dev
   b. On CentOS : yum install lksctp-tools-devel
4. Install PCAP:
   a. On ubuntu : sudo apt-get install -y libpcap-dev
   b. On CentOS : yum install libpcap-devel


Pre-requisite for running O1 module:
-----------------------------------
Install netconf server
----------------------

1.	Create new netconf user (login with root user and run following command)
	$adduser --system netconf && \
        echo "netconf:netconf" | chpasswd

	$mkdir -p /home/netconf/.ssh && \
	ssh-keygen -A && \
	ssh-keygen -t dsa -P '' -f /home/netconf/.ssh/id_dsa && \
        cat /home/netconf/.ssh/id_dsa.pub > /home/netconf/.ssh/authorized_keys
2.	Install netconf packages. 
	$cd l2/build/o1/
	$chmod +x install_lib.sh
	$ ./install_lib.sh

Install the yang module
-----------------------
1. cd l2/build/o1/yang
   sysrepoctl -i o-ran-sc-odu-alarm-v1.yang


How to Clean and Build:
-----------------------
1. Building ODU binary:
   a. Build folder
         cd l2/build/odu
   b. Building ODU binary
         make odu MACHINE=BIT64 MODE=FDD

         Build with O1 module enabled:
         make odu MACHINE=BIT64 MODE=FDD O1_ENABLE=YES

   c. Cleaning ODU binary
         make clean_odu MACHINE=BIT64 MODE=FDD

2. Building CU Stub binary:
   a. Build folder
         cd l2/build/odu
   b. Building CU Stub binary
         make cu_stub NODE=TEST_STUB MACHINE=BIT64 MODE=FDD
   c. Cleaning CU Stub binary
         make clean_cu NODE=TEST_STUB MACHINE=BIT64 MODE=FDD

3. Building RIC Stub binary:
   a. Build folder
         cd l2/build/odu
   b. Building RIC Stub binary
         make ric_stub NODE=TEST_STUB MACHINE=BIT64 MODE=FDD
   c. Cleaning RIC Stub binary
         make clean_ric NODE=TEST_STUB MACHINE=BIT64 MODE=FDD

4. Cleaning ODU, CU Stub and RIC Stub:
      make clean_all

5. Building O1 binary:
   a. Build folder
         cd l2/build/o1
   b. Building O1 binary
         make o1 MACHINE=BIT64
   c. Cleaning O1 binary
         make clean_o1 


How to execute:
---------------
1. Assign virtual IP addresses as follows:
      ifconfig <interface name>:ODU "192.168.130.81"
      ifconfig <interface name>:CU_STUB "192.168.130.82"
      ifconfig <interface name>:RIC_STUB "192.168.130.80"

2. CU execution folder:
      cd l2/bin/cu_stub
     
3. Run CU Stub binary:
      ./cu_stub

4. RIC execution folder:
      cd l2/bin/ric_stub
     
5. Run RIC Stub binary:
      ./ric_stub

6. DU execution folder:
      cd l2/bin/odu
     
7. Run ODU binary:
      ./odu

8. O1 execution folder:
      cd l2/build/o1/bin/o1

9. Run O1 binary:
      ./o1

PS: CU stub and RIC stub must be run (in no particular sequence) before ODU
    If O1 module is enabled it must be run before ODU