Efficient Software Hooks

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Efficient Software Hooks By Eiji Hashigami,

Honda R&D Co., Ltd. Automobile R&D Center

Honda R&D Co., Ltd. Automobile R&D Center implements new EHOOKS tool Honda R&D Co., Ltd. Automobile R&D Center is the first automaker in the world to embark on a pilot project using EHOOKS automatic hook points generation technology. Powertrain engine control units (ECUs) require continuous development of controls due to advances in high-speed processing and technology as well as demands from society such as environmental considerations. As a result, an increase in the labor hours needed for development efforts has been unavoidable. This is an important issue faced by every

automaker, and EHOOKS from ETAS will play a major role in the development of ECU technologies that are growing in complexity. In ordinary ECU development, ECU functions are determined through repeated consultation between automakers and ECU suppliers on the subject of specifications. At Honda

R&D Co., Ltd. Automobile R&D Center, this consultation is conducted after first identifying the parts of delivered ECU software to be verified and preparing software modification requests. Next, a waiting period ordinarily ranging from several days to several weeks is required until bypass hooks have been implemented, tested, and delivered. Since this

process of determining ECU functions arises with repeated software modifications, how to improve process efficiency was a major concern for both Honda and its suppliers. For this reason, we looked at ETAS’ EHOOKS. EHOOKS is a tool that generates bypass hook code at a machine-language level without a need for source code. It does this by using a simplified Instruction Set Simulator (ISS) to analyze RAM access at a machine-language level and identify hooking points (through machine-language conversion). In other words, since it uses a tool to automate the process of tasks traditionally carried out by ECU suppliers, it promises to reduce wait time for software modifications in addition to time required for document preparation and meetings. This leads to reductions in labor hours for both automakers and ECU suppliers. When initially released, the EHOOKSDEV tool required that configuration of bypass variables be described

manually in XML format. This task took some time. Also, since these were handled all manually, even if the necessary software could be generated instantly, difficulties resulted in the need for preparatory processes. However, since the upgraded EHOOKS version has added a graphical user interface and enhanced functions, the final version even makes it possible to intuitively understand the GUI configuration contents. Since a tool with an intuitively understandable GUI is easy even for beginners to master, the tool can be used without having to depend on specific, dedicated personnel. Another benefit is the fact that the content of EHOOKS-DEV configurations can be managed across projects, so that identical configuration content can be shared within the same project even when staff changes. Also, thanks to the consistent and regular follow-up from ETAS and their quick responses to any prob-

lems, projects can be advanced smoothly without work interruptions. In addition, use of the four hook types provided by EHOOKS has broadened the tool’s use beyond the initially anticipated use of hook code generation in bypass processes. For example, even if a bug has been discovered in ECU software that has been delivered, use of EHOOKS makes it possible to fix it in our own environment without waiting for fixes by the ECU supplier. Also, by using the on-target bypass provided by EHOOKS, the once thought impossible matter of conducting on-chip software-synchronization bypass experiments may now be realized. At this time, Honda R&D Co., Ltd. Automobile R&D Center is attempting the automation of ECU software verification by combining EHOOKS with its HiL system (LABCAR). The ECU software currently used has numerous error flags indicating internal defects. Verification of these had

ECU project files

A2L

Hex

A2L

No upper limit on variables disclosed

Model to be verified Test mode run

Hex

EHOOKS-DEV Configuration / Change of bypass hook points

Forced rewrite of RAM regarding internal error and function for hook points

Implementation / Run of the bypass application

Results

External bypass

On-target bypass

Constant value / calibration bypass

for large-scale rapid prototypes

for small-scale rapid prototypes

for diagnosis /debugging

Error codes I

ECU

Hex’

Host PC

HiL (LABCAR)

EHOOKS-DEV Hook points generation

Unlimited change of bypass hook points

A2L’

Diagnostic Interface J2534

Architecture of the automated ECU software calibration: Use case at Honda.

V Actual Position Perc Actual Position

Throttle Position

perc

Data area

Data area

Code area

Code area

Unused area

Prototype application

Utilize CPU unused memory

Unused area Rewrite of the parameter value

Various bypass applications provided by EHOOKS.

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required reproducing the error conditions and setting a flag for each condition corresponding to the subject test item. In particular, reproduction is extremely difficult for memorylevel internal defects that cannot operate at the HiL level. However, using the calibration bypass provided by EHOOKS makes it possible to write values to variables that usually are read only. In other words, the error conditions needed for decision control can be reproduced as pseudoconditions, by directly setting the condition flag to “ON” without reproducing the actual error conditions.

BIOGAS POWER

The ECU judges an error condition from this flag value, outputting an error code. The system is designed so that this code is read by a diagnostics tool and returned to the verification PC. Use of this feature has succeeded in reducing labor hours by realizing automated testing into the process. Currently, testing automation in combination with the HiL system is underway. Testing is being automated by preparing an error-pattern matrix on the verification PC and then executing the subject error conditions in LABCAR, or directly manipulating the

THE CHALLENGE In ordinary ECU development, ECU functions are determined through repeated consultation between automakers and ECU suppliers on the subject of specifications. How to improve process efficiency and reduce labor hours was a major concern for both Honda and its suppliers. THE SOLUTION EHOOKS is a tool that generates bypass hook code at a machinelanguage level without a need for source code. Bypass hooks formerly generated by ECU suppliers can now be implemented by OEMs. THE BENEFIT The time formerly required for source code modifications by the ECU supplier for an ECU development project could be shortened from several months to as little as a few days.

error flag externally using a conformity bypass generated in advance in EHOOKS. This has automated testing that includes error patterns indicating internal errors. Furthermore, as the next process, we are considering experiments on synchronizing ECU software behavior on this system. Making such a system real is expected to make it possible to complete testing processes the day after testing begins, instead of the several days to several weeks needed currently. In light of this performance, the decision has also been made to adopt EHOOKS, the deployment of which is presently limited to advanced development sections, for mass-production sections in the future. Throughout this pilot program, the results we have been able to obtain with EHOOKS have exceeded our expectations. Using our experience describing EHOOKS configuration manually using XML format, which at first had been difficult, we now can resolve a certain degree of problems in-house. Also, we have been able to shorten the time formerly required for source-code modifications by the ECU supplier for an ECU development project from several months to as little as a few days by adopting the EHOOKS-DEV tool. Since use of this tool makes it possible to verify analysis and improvements for critical problems on the OEM side, we believe EHOOKS is highly significant and meaningful even under time-critical conditions. In the future, we look forward to further expansion and standardization by means such as achieving compatibility with other ECU systems and establishment of EHOOKS functions as expanded functions of ETAS’ own AUTOSAR BSMs (Basic Software Modules).

World Record with Biogas Power By Dr. Ulrich Lauff and Ralf Rick, ETAS

ETAS tools very much at home in pit row April 19, 2009. The sparkle of a sunny day creates ideal conditions at the test track in Papenburg, Lower Saxony. At 10:45 this morning, Jürgen Hohenester hits the track for the first time today. He wants to warm up the biogas powered Audi RS4 racecar and make sure the road surface is in ideal condition.

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