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This page provides the details and guidance to the SoC Vendors on how to adopt RDK-B. The porting procedure and the procedures for SoC to get an RDK based Platform up and running is also described in detail.

Before You Begin

RDK License

SoC vendors are advised to get into an agreement with RDK Management LLC to obtain the free license so as to use the complete RDK Code base in their platform. More details about license is available at https://rdkcentral.com/licenses/ . Please email info@rdkcentral.com if you have additional questions about licenses or membership

Bringing up RDK by SoC - Approach

This section will detail the recommended step by step procedure of adopting RDK by a SoC

Product Specifications

The first step to get a fully functional product is to define the product features and see if they meet the standard requirements. See here to know what are all the features available in RDK-B and can implement based on your requirement. SoC can use this as a guide while engineering the RDK SoC platform.

RDKM On-boarding

RDKM provides a collaboration zone facility for SoCs to facilitate easier engineering of RDK based devices. The collaboration zone will help SoCs to work with OEMs, RDKM and any 3^rd party along with a common space to develop & integrate, manage and verify the device. The zone includes facilities for code management, a confluence based RDK Wiki for knowledge management & sharing, a JIRA for tracking activity progress, issues as well as to manage the activities, a test setup to validate devices. The access restrictions implemented will help the collaboration zone to be accessible only for the authorized personnel thereby guarding any sensitive information related to SoC/OEM/Third party.

Roles & Responsibilities

A table explaining the roles & responsibilities of SoC & RDKM in the collaboration zone is given below:

 Click here for more details such as creating collaboration zone, creating user accounts for SoC Members, creating a JIRA project for SoC etc.

Product Engineering

Once the product features are decided, the device engineering can be started. SoC needs to decide on the hardware layout that incorporates components to the target board. Device will be categorized as Low Profile and High Profile device based on the hardware capabilities. In a low profile device 4k support might be optional but it is expected to have 4k support in high profile device.

Sample Reference Flash Layout (Optional) :

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SoC Platform Firmware

SoC can make use of the below details available to start developing a Yocto build to engineer the device firmware builds based on RDK Yocto build setup.

Yocto Manifests

Yocto based RDK builds are flexible enough to easily accommodate SoC / OEM / MSO / third party changes. The starting point for the Yocto builds are a manifest file. The manifest file is an xml file that contains details of the different open embedded Yocto build layers, meta layers , rdk as well as open source components that needs to be fetched during initial stages ( than during bitbake time ) as well as the URL locations from where the data can be pulled. A set of sample manifests that can be used as a template for developing SoC specific manifests are given below

 Click here for more details on Yocto Manifests

For more details on getting RDK-B ported to an OEM device, please refer the links RDK-B SoC Specific Porting and Guideline for SoC and OEM Vendors

SoC/OEM meta-layer creation

To match the layered structure of Yocto builds, a SoC specific layer is used to include SoC changes and additions. Use the yocto-layer create sub-command to create a new general layer.

There shall be separate device (machine) configuration file (.conf) for each device for the particular chip family for which the layer is intended for. The general naming terminology for SoC layer is meta-rdk-SoC-<SoC name>

The device (machine) configuration file shall include corresponding include (.inc) file to get machine configuration details.

 Click here for more details on SoC/OEM meta-layer creation

TDK and RDK Certification Suite Package

RDKM offers an in-house Test & certification suite that facilitates SoCs to get their IP Set-top product certified as RDK Compliant device.

Certification program includes testing which validates the RDK stack on the device with defined test suite called as RDK Certification Test Suite. It is mandatory to go through this program in order to brand user's platform as RDK compliant product.

Certification suite is available at RDK IP Set-top Product Certification(only for RDK licensee) and for TDK test app please refer TDK-BV Documentation(only for RDK licensee).

SDK Releases

Once the RDK bring-up in SoC is completed, the vendor needs to plan on the delivery of the software to OEM vendors. This usually happens in 2 ways:

HAL + SDK binary

In this approach will make use of the RDK Artifactory server. Artifactory server is a Repository Manager that functions as a single access point organizing all the binary resources including proprietary libraries, remote artifacts and other 3rd party resources. It is a secure and restricted server, only collaboration members will have access to this server.

SoC vendor can define a HAL layer, share the source of HAL & yocto meta layer that can be stored in RDK CMF Git repository (which will be shared only  to authorized OEM vendors who will work in collaboration with the SoC vendor), share the SDK binary that can be stored in RDK Artifactory (which will be shared only to authorized OEM vendors who will work in collaboration with the SoC vendor) and then publish necessary documentation on how to build the SoC SDK. SoC vendor can use the git/ Artifactory for periodic updated (for releases) or for bug fixes. All the source code, binary and documentation will be strictly access restricted and access will be allowed only for authorized personnel by SoC vendor.

Artifactory server can be accessed by adding the Artifactory details and login credentials in the .netrc file, just like it is done for normal git repositories. A sample is given below:

machine your.artifactory.host
login YOUR_ARTIFACTORY_USERNAME
password YOUR_PASSWORD_OR_KEY_OR_TOKEN

Complete source code

In this approach, SoC vendor can define a HAL layer, share the source of HAL , yocto meta layer and SDK source code that can be stored in RDK CMF Git repository( which will be shared only  to authorized OEM vendors who will work in collaboration with the SoC vendor )  and then publish necessary documentation on how to build the SoC SDK. SoC vendor can use the git for periodic updated ( for releases ) or for bug fixes. All the source code and documentation will be strictly access restricted and access will be allowed only for authorized personnel by SoC vendor.

For both approaches, the RDKM collaboration zone will be used with strict access restrictions.

Collaboration with OEMs

After a successful bring up of RDK on SoC platform, the next step will be to allow OEMs to work with SoCs to get a device based on the SoC platform. RDKM offers collaboration space for SoCs which would help SoCs to collaborate with OEM and RDK teams (as well as any 3rd party) in their journey to engineer a successful RDK product. RDKM collaboration zone includes features like (but not limited to) CMF facility to maintain build manifests as well as SoC/OEM specific code, SoC SDK artifact storage facility, JIRA & RDK Wiki spaces, integration with Test & Certification suites, monthly & release tagging etc.

Please refer RDKM On-boarding for more details on facilities available for SoCs and OEMs as part of collaboration zone . In short, it will include:

• Access restricted Git repositories and Artifactory servers
• Access restricted Confluence and JIRA spaces for Management and Documentation
• Access to RDKM support as well as extended documentation
• Access to test & certification support 

RDK porting guide to SoC vendors

The aim of this SoC porting guide is to guide SoC Vendors on how to port RDK to their platforms.

Step 1 : Get a board with Linux and drivers

RDK is based on Yocto Linux. Prior to porting RDK on a SoC , the precondition is to have the SoC platform running on Linux. The Linux version can be a SoC specific one with kernal hardening and other OS optimizations specific to SoC, as RDK could easily run on top of vendor specific Linux. SoC should also provide drivers for the other peripherals in SoC platform, like WiFi, so that the unit can work independently and completely from a SoC point of view.

Step 2 : Move the build to Yocto, compare it to supported Yocto version of RDK

Once SoC vendor is ready with an own port of Linux + drivers for the SoC platform, it is time to migrate the platform to Yocto based builds. If the SoC is already having a Yocto based Linux, this step can be skipped. The current Yocto versions supported are Yocto 3.1- Dunfell ( preferred ) as well as Yocto 2.2- Morty ( soon to be deprecated )

Yocto 3.1 Upgradation support the following:

• Version upgrades for bitbake, GStreamer and other OE components
• Linux kernel 5.4 or above
• Extensible SDK

Each component in RDK is a standalone repository with its own individual build tools producing a library or set of binaries. When OE layers are upgraded to the newer versions, necessary changes need to be made in the RDK Yocto meta layers which use these components, to avoid build failures.

Step 3 : Compare and verify the compiler flags used in RDK and in platform to avoid issues

This is an important step while porting RDK to a new SoC platform. RDK Linux is built with considering particular build flags/features in target platform( For example, RDK considers hardware floating point in platform where as some platforms are on software based floating point ). SoC vendor need to analyze such flags in RDK and then make a comparison with the existing SoC platform Linux to ensure compatibility or to understand the required modifications in RDK code so as to house the compatibility changes

Specific DISTRO_FEATURES can be added to support build time flag for specific platforms. For example : DISTRO_FEATURES_append = " referencepltfm "

Step 4 : Compare the open source versions used in platform as different versions will cause problems

Depending on the Yocto version, the RDK build will be working with some particular version of Open source components. This might either be a dependency with the Yocto version compatibility as such or with RDK ( functionality or license issues ). If the SoC Linux has some version dependency on particular open source software and, if it conflicts with the version in RDK, vendor needs to make required changes to make the open source version to match the RDK requirements as best as possible, by adding required patches in SoC platform 

Check below layers for all opensourced version packages recipes used in RDK. If multiple recipes with different versions are available, then check for the value of PREFFERED_VERSION_<recipe name> set.

Meta layers : -  meta-openembedded, openembedded-core, meta-rdk-ext, meta-rdk, meta-cmf

Step 5 : Move the RDK recipes to platform Yocto build

For platform specific recipes, keep them in SoC meta layer. While it is a good practice to start afresh with a new manifest for the target platform, manifest file for  a similar featured platform can be used as a starting point too. Check all device specific repos in the reference manifest, and ensure corresponding device repos are created for this new device as needed, and update the manifest with these updated repos

• Create artifactory repo for the project with appropriate permissions for vendors. This is used for hosting any binaries required for the project
• Check-in SoC components - tool chain, SDK, kernel, drivers, etc.. to corresponding SoC gerrit repos/ artifactory as applicable
• Populate meta SoC layer with initial set of changes needed to build kernel, SoC components, etc..
• If there is any SoC reference board exists, create corresponding machine configuration in SoC layer, and create a image target to be able to build final image for the reference board. This layer should be separated out with in meta SoC layer from other common SoC, common chip sub layers which will be usually used by meta oem layer as well.
• Populate meta oem layer with machine configuration and other bare minimum changes required to generate a target image for OEM board.
• machine configuration can be updated with "NEEDED_BSPLAYERS" field to include required SoC, OEM layers in the build
• Any unwanted recipes during early stage of bring up can be masked using BBMASK, if needed.

Step 6 : Get a successful build

Add platform specific main recipe to create image.

HAL implementation by SoC

Device Settings

Device settings component is having a HAL interface to control device specific peripherals such as video port, audio port and display and front panel. 

More details on HAL interface can be found here: Device Settings HAL Types & Public API DTCP HAL Interfaces.

DTCP

Integrates the SoC provided DTCP library with DTCP/IP manager Interface implementation which manages source/sink DTCP/IP sessions and performs the encryption/decryption.

HAL Interface specification: DTCP HAL Interfaces

tr69hostif

Contains SoC specific MOCA libraries, headers and MOCA profile codes.

API Details: TR69 Host Interface Handler

For more details on tr69hostif, please refer: tr69hostif

gst-plugins-rdk /qamtunersrc

qamtunersrc is a push based gstreamer source plugin which tunes to the given service and provides the SPTS data.

• Manages tuner and demux
• Filters PIDs required for SPTS
• Output SPTS as gstreamer buffer

Properties

1. Modulation:
2. Frequency: frequency to tune in KHZ
3. Tunerid: Tuner Handle

Depends on platform specific libraries for tune, filtering, and pod functionalities.

gst-plugins-SoC /playersinkbin

Playersinkbin is a gstreamer bin element consisting of demux, decoder and sink elements. A template file gstplayersinkbin.c.template and gstplayersinkbin.h.template are provided as a reference for SoC implementation. SoC has to add details of platform specific plugins and implement the required properties expected out of them.

hdmicec

SDK Vendors should implement CEC driver interface API as specified in hdmi_cec_driver.h

HAL Interface Specificcation: HDMI-CEC HAL APIs specification

iarmmgrs

Power, IR and DeepSleep modules are having SoC dependency. APIs are specified in plat_power.h, plat_ir.h and deepSleepMgr.h

More details about APIs can be found here

westeros-SoC

Contains functions for creating and handling native eglwindow. HAL APIs are specified in westeros-gl.h

Wi-Fi (Client)

Wi-Fi Client HAL provides an interface (data structures and API) to interact with underlying Wi-Fi driver and enabling the client to be connected with an Access Point.

HAL APIs are specified in wifi_client_hal.h. Doxygen Link: Wifi HAL API Specification

Provisioning - iCrypto

Set of Cryptographic APIs Implementation, can be used to achieve all type of Cryptographic requirements from Premium App.

Graphics - westeros backend

Media Pipeline Backend layer is a module in device layer which glues the media pipeline capabilities of the device to that of the IgnitionX.

Input key handling

As part of integrating Premium Apps as a native application on the RDK stack, the Premium Apps Video Porting (PVP) Layer needs to be implemented. The PVP Layer consists of the following modules:

• Ignition Device Layer
  • Common
  • Display
  • Input
  • TTS
  • Secure Storage
  • Message Bus
• Device Properties Provider
• Media Pipeline Backend
• PlayReady DRM

Media Playback - gstreamer

Abstraction layer for third-party applications to get specific GStreamer values from the SoC pipeline.

DRM (playready, widevine, TEE, SVP etc.)

Amazon assets are encrypted using Microsoft PlayReady. A robust implementation of the PlayReady must be provided for porting kit to decrypt assets.

TTS

Text-to-speech converts text into spoken voice output to help customers navigate the Prime Video application without seeing the screen. Text-to-speech is mandatory for the US region and optional in other regions.

Closed Caption

ccReader module which does the closed caption decoding is having HAL dependency. APIs are specified in ccDataReader.h

More details on HAL interface can be found here: closed Caption HAL APIs

DirectFB

Graphics library porting for SoC.

For more details on DirectFB, please refer: DirectFB

DVRManager

AES Encryption and decryption of packets handled from DVRManager SoC Layer.

Mediaframework

Porting of mediaframework involves porting of the following sub-modules:

• halcdl
• haldsg
• halpod
• halsnmp
• halmfr
• halplatform

Details about HAL APIs that require porting is published as part of Doxygen Documentation activity in Mediaframework HAL API Specification.

ServiceManager

Service Manager as such doesn't have an HAL part to be implemented, however it can have a platform part that extends/alters it's functionality with few of the legacy services such as Power management (deep sleep), Front panel control, and so on.

For more details on ServiceManager, please refer: ServiceManager

wpeframework/OCDMi

PlayReady and WideVine Open CDMi implementation - specific to platform.