HAL Interface for Raspberry Pi 4 Reference Platform

The Hardware Abstraction Layer (HAL) in the RDK-B project provides an interface for hardware-dependent operations. This document explores the available HAL components in the halinterface directory and identifies those relevant to the Raspberry Pi 4 reference platform.

Hal Version : 3

Directory Structure

Located at: rdkb/components/opensource/ccsp/halinterface/

The directory contains various HAL implementations, categorized as follows:

1. Network and Ethernet HALs

• vlan_eth_hal.h - VLAN Ethernet HAL

• vlan_hal_emu.h - VLAN HAL Emulator

• xdsl_hal.h - xDSL HAL (Not relevant to RPi4)

• xtm_hal.h - Transmit Multiplexer HAL (Not relevant to RPi4)

2. Wireless (WiFi) HALs

• wifi_hal.h - Core WiFi HAL (Relevant to RPi4)

• wifi_hal_emu.h - WiFi HAL Emulator

• wifi_hal_extender.h - WiFi Extender HAL

• wifi_hal_client_mgt.h - WiFi Client Management

• wifi_hal_radio.h - WiFi Radio Control

• wifi_hal_sta.h - WiFi Station HAL

• wifi_hal_telemetry.h - WiFi Telemetry Support

3. Broadband & Modem HALs

• dpoe_hal.h - DOCSIS Passive Optical Ethernet (Not relevant to RPi4)

• ccsp_hal_dhcpv4_emu_api.h - DHCPv4 Emulator API

4. Voice and Bluetooth HALs

• voice_hal.h - Voice Processing HAL

• bt_hal.h - Bluetooth HAL (Relevant to RPi4 if Bluetooth is needed)

5. TR-069 and Device Management HALs

• Tr69_Tlv.h - TR-069 TLV Management

HALs Relevant to Raspberry Pi 4

For Raspberry Pi 4, the most relevant HALs include:

1. WiFi HALs:

   • wifi_hal.h

   • wifi_hal_radio.h

   • wifi_hal_sta.h

   • wifi_hal_client_mgt.h

   • wifi_hal_telemetry.h

2. Ethernet & VLAN HALs:

   • vlan_eth_hal.h

   • vlan_hal_emu.h

3. Bluetooth HAL:

   • bt_hal.h

4. Voice HAL (If applicable):

   • voice_hal.h

wifi_hal.h:
It serves as the central interface for interacting with different WiFi components like the radio, access point (AP), station (STA), client management, telemetry, and extenders. The APIs defined in wifi_hal.h are meant to be used across multiple modules of the WiFi stack. For example, the wifi_hal_generic.h file may include basic functionality needed by all other modules, while the wifi_hal_radio.h, wifi_hal_ap.h, and other headers provide specific functionality for each part of the WiFi subsystem.