/*
 * BAL Programmers Guide - introduction
 */

/** \mainpage BAL Public Interface Concept

\section intro Introduction
This document describes the BAL user interface. The user interface is constructed from a
small set of public APIs and an objects model.

The objects model is designed to manage different entities in the system, and enables a simple and intuitive
approach for managing line card.

The API layer is designed to enable the management of line card containing muultiple MAC and SWITCH devices
and support any host application architecture. It includes a set of APIs to access the line card configuration and
asynchronous indications to send events to the host application.

The API layer is part of the Broadcom® BAL SDK, which is provided as C source code, which is
independent of the CPU and operating system being used.

\section object_model_table BAL Object Model

The system is modeled as a set of managed objects. The term “object” here doesn’t imply any inheritance, it
means an entity that can be addressed individually and has a set of properties (attributes) and methods
(operations), for example, access_terminal, flow, etc.

Each object can have multiple properties (aka attributes), whereas a property is an object parameter that can be set or
retrieved independently.
	- A property is a simple type or a structure containing one or more fields, where fields can themselves be
structures
	- Each property has a specific permission type, such as Read-Only (RO) and Read-Write (RW).

Object properties are grouped into sections/management groups. The following sections can contain zero or
more properties:
	- Key—Field(s) that uniquely identify the object instance (for example, subscriber_terminal key = {subs_id, intf_id}).
	- Configuration
	    - Read-Write, Read-Only and Write-Only configuration properties
	- Statistics
		- Performance monitoring counters
		- Debug counters
	- Autonomous Indications
		- Notifications that are generated asynchronously.
		  Indications can be either autonomous (such as alarms) or asynchronous responses to previously
          submitted configuration change (for instance, subscriber_terminal admin_state=up request).

\section object_model_prop Object and Properties Implementation

\subsection object_model_structs Object Structures

The main input parameter of all the APIs is an object structure, referred to as the Object Request Message. Each
object section has a different structure that includes a generic header, object key, and a specific section structure
according to the section type (for example, configuration, statics, etc).
	- Generic header: A basic component of all the different section structures is the object generic header
	  \ref bcmbal_obj

	- The configuration structure bcmbal_xx_cfg contains:
		- The generic header \ref bcmbal_cfg
		- The object key, if any
		- The structure bcmbal_xx_cfg_data, containing all object configuration properties

	- This statistics structure bcmbal_xx_stat contains:
		- The generic header \ref bcmbal_stat
		- The object key, if any
		- The structure bcmbal_xx_stat_data, containing all the object statistics

	- The per-autonomous indication structure bcmbal_xx_auto_yy contains:
		- The generic header \ref bcmbal_auto
			- The autonomous message ID is stored in the subgroup field.
		- The object key, if any
		- The structure bcmbal_xx_auto_yy_data, containing all indication properties, if any

\subsection object_model_init_macros Structure Initialization Macros
The following macros are used for initializing objects:
	- \ref BCMBAL_CFG_INIT(cfg_msg, _object, _key)
	- \ref BCMBAL_STAT_INIT(stat_msg, _object, _key)

The macros perform the following tasks:
	- Check that the structure matches the object section.
	- Clear all control fields in the generic header \ref bcmbal_obj.

\subsection object_model_prop_macros Property Presence Mask Manipulation Macros
The presence mask indicates which of the properties in the object structure need to be accessed (set/get, etc.)
The mask is a bit field, wherein each bit corresponds to a specific property. The following macros should be used
for setting the presence mask:

 - Set configuration parameter value:\n
	\ref BCMBAL_CFG_PROP_SET(_msg, _object, _parm_name, _parm_value)
 - Indicate that the property should be fetched by a bcmolt_cfg_get() request:\n
	\ref BCMBAL_CFG_PROP_GET(_msg, _object, _parm_name)
 - Indicate that the statistic should be fetched by a bcmolt_stat_get() request:\n
	\ref BCMBAL_STAT_PROP_GET(_msg, _object, _parm_name)

\subsection object_model_enums Enumerations
In the following descriptions, XX is the object name and YY is the property name from the XML model.

The system model includes the enumerations:
	- The bcmbal_obj_id enumeration lists all objects. It includes per-object BCMBAL_OBJ_ID_XX constants,
		where XX is the object name from the XML model.
	- The bcmbal_xx_cfg_id enumeration lists all XX objects' properties from the “Configuration” section in the
		XML model. It includes the BCMBAL_XX_CFG_ID_YY constants.
	- The bcmbal_xx_stat_id enumeration lists all XX object's properties from the “Statistics” section in the XML
		model. It includes the BCMBAL_XX_STAT_ID_YY constants.
	- The bcmbal_xx_auto_id enumeration lists all XX object's indications from the “Autonomous Indications”
		section in the XML model. It includes the BCMBAL_XX_AUTO_ID_YY constants.

\section api_section BAL Public API
  See \ref api in API Reference chapter
*/