Why flag ?

• If the code changes has to be enabled only on certain scenarios or only applicable for specific boards , then we have to define the flag .

Defining a new flag 

• The flag has to be defined in ccsp_common.inc file
• There are two ways to define the flag

                      1. Having the flag enabled always
                      2. Enabling only for specific board or on specific condition

Having the flag enabled always 

• Go to ccsp_common.inc file
• Add the flag under "CFLAGS_append +="  

• Syntax

  CFLAGS_append +=  " <FLAG> "

• Sample 

  
• By this method, the flag is always set to 1 (true)
• Now add the flag at required pieces of code

Enabling only for specific board or on specific condition

• Add the flag using DISTRO_FEATURE in ccsp_common.inc file as below

• Syntax 

  CFLAGS_append += " ${@bb.utils.contains('DISTRO_FEATURES', '<keyword>', '<FLAG>', '', d)}"

• Now to enable the flag for the specific platform , invoke from platform specific machine conf file 

• Syntax

  DISTRO_FEATURES_append = " ........ <keyword> "

• Sample
   In ccsp_common.inc

  

  
   In raspberrypi-rdk-broadband.conf
  

           This enables RDK_REF_PLATFORM_ flag for rpi platform . 

• Using DISTRO method 

1. the package enable/disable for the specific platform can be controlled 
   
2. installation of file based on feature availability 
   
3. Functionality of feature can be controlled