Since its inception, the Linux Foundation’s Automotive Grade Linux project has promoted itself as a collaborative open source project. With the release of the first AGL Requirements Specification for Linux-based in-vehicle infotainment (IVI), AGL has earned that description more than ever.

In July 2014, AGL released its first AGL reference platform built on the Tizen IVI platform running HTML5 apps. The new release instead details precise specifications and requirements for any AGL-compliant IVI stack. For the first time, automakers, automotive suppliers, and open source developers can collaborate on refining the spec — the first draft of a common, Linux-based software stack for the connected car.

Announced this week at the Automotive Linux Summit in Tokyo, the specification allows OEMs and suppliers to identify gaps between code and requirements. Automotive companies can then provide input to the developer community for resolution in future AGL releases. This will be particularly helpful for supporting multiple architectures, says Dan Cauchy, general manager of automotive at the Linux Foundation, in an interview with Linux.com.

The Tizen IVI stack released last year was based on draft version 0.82 of the spec, which was not published at the time. Since then, the reference stack has been updated with improvements such as moving to a Crosswalk runtime and adopting Smack as the default security framework. Smack is now being considered for the full Specification, as well, says Cauchy. There has also been considerable progress on supporting the Renesas R-Car platform, he adds.

While the specification defines a standard, as opposed to supplying a reference platform, Cauchy says there is no plan to implement a compliance program at this time. “The specification is used to identify the gaps between what is required and what is in the code,” he says. “Where there are gaps, we will implement those features and functions. Our aim is still to use existing code whenever possible.”

Cauchy emphasizes that the spec is “more than just a technical document.” The document is “a clear indication that the automakers and suppliers are adopting an open development methodology for the first time,” says Cauchy. “This will allow the industry to leverage and interact directly with thousands of open source developers, by providing requirements directly to the developer community.”

According to Cauchy, the AGL spec differs from the Linux-oriented GENIVI Alliance spec in that AGL is “completely open source, both in the specification and the code.” This also relates to governance, he says. “Anyone can participate in AGL’s development,” says Cauchy.

Another difference is that AGL “is focusing on a complete reference platform, and not just components,” says Cauchy. The platform includes the Linux kernel, board support package, middleware, application framework, and support for both native-Linux and HTML5 apps. “Also, there are plans to have multiple profiles of the same base platform so that we can address functions such as instrument cluster, heads up display, and telematics,” says Cauchy. “Basically, if the car runs Linux, we want it all to be based on AGL, no matter the application or function.”

Despite the distinctions Cauchy makes in regard to GENIVI, there is hope that the two projects could collaborate, as Cauchy suggested might happen last July. At the Automotive Linux Summit, the AGL announced that it has started building a “Unified Code Base, whereby we will be taking the best of AGL, Tizen, and GENIVI projects and combining them into a single AGL distribution for the entire industry,” explains Cauchy. “The Unified Code Base will be based on creating an architecture of multiple Yocto-based meta layers. This will be a big step forward in eliminating the fragmentation in the industry.”

So far, there has been no official announcement from either the AGL or GENIVI camps, and no further explanation from Cauchy. Further details will be forthcoming, he adds.

AGL: IVI now, clusters and telematics tomorrow

For now, AGL is primarily focused on IVI, defining requirements for services such as WiFi, Bluetooth, multimedia, application lifecycle management, windowing, power management, and location based services. It does, however, define connectivity and interaction with CAN- and MOST-based vehicle buses, complete with APIs for middleware and applications.

“There are also growing requirements for aligning with IoT efforts for seamless connectivity to other devices and the cloud,” says Cauchy. He notes that on the AGL’s related Tizen IVI platform, “there has been a lot of work on the Remote Vehicle Interaction project. The RVI sub-project is said to “build a reference implementation of the infrastructure that drives next generation’s connected vehicle services.”

There are no current plans to add Android Auto or Apple CarPlay support to AGL, says Cauchy. However, he notes that “an AGL based system is perfect for implementing a CarPlay or Android Auto solution. It is up to the automotive OEM to port CarPlay or Android Auto and take care of the necessary agreements with Apple and Google.”

Cauchy also went out of his way to correct the common misperception that these “projection” technologies are complete IVI specs like AGL, GENIVI, or proprietary platforms such as Windows Embedded Automotive. While Google has suggested that Android Auto could evolve into such a full-blown stack, it is currently limited to defining interactions with Android smartphones and tablets within the car.

A week ago, Hyundai announced the first Android Auto implementation from a carmaker. The technology will appear in its 2015 Sonata cars.

This week, Mitsubishi announced it would add both Android Auto and CarPlay support to the European version of the 2016 Pajero SUV, known as the Montero in the U.S. It’s unclear if this is related to Mitsubishi’s recently announced, FlexConnect.IVI system, which runs Android on a Texas Instruments Jacinto 6 SoC. FlexConnect.IVI is notable for controlling IVI, heads up display, and cluster displays simultaneously. Finally, Pioneer recently announced Android Auto support in some of its NEX aftermarket multimedia receivers.

Cauchy had no comment on the progress of the GlobalLogic-backed Automotive Grade Android (AGA), which we reported on last summer. This offshoot of AGA, of which GlobalLogic is a Silver member, is a Jacinto 6-based Android reference platform that uses Xen virtualization technology.

At the Automotive Linux Summit, AGL also announced four new members including Sony, Alps Electric, Konsulko Group, and Virtual Open Systems. They join several dozen other members, led by gold members Intel, Jaguar/Land Rover, Panasonic, Renesas, ST, and Toyota.

Cauchy wouldn’t say when the first cars with AGL-compliant systems would hit the road. However, he noted that Toyota and Jaguar/Land Rover are both very active in the project. Other carmaker members include Nissan and Mitsubishi.

The open source AGL Requirements Specification v1.0 is now available for public download. Participants can call upon collaborative tools such as Git repositories, Gerrit code review, Jira bug tracking, and a Doors database.