page 1 ajacs and hip/automotive antonio kung - trialog copyright (c) 2002 j consortium ®, inc. all...

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AJACS and HIP/Automotive

Antonio Kung - Trialog

Copyright (c) 2002 J Consortium®, Inc. All Rights Reserved

J Consortium is a registered trademark in the United States.JavaTM is a trademark of Sun Microsystems in the United States and other countries.

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Content

AJACS rationale Technical approach and related issues HIP/Automotive working group

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The AJACS Project

Applying Java to Automotive Control Systems Web site : www.ajacs.org Consortium

– Trialog– PSA (Peugeot-Citroën)– CRF (Centro Riserche Fiat )– Mecel (technology centre of Delphi)– University of Karslruhe

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AJACS Rationale

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The Trend Today

More global applications– Multiplexing– Connectivity

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Two Worlds

Infotainment : navigation, Internet, telecom...– AMIC initiative (www.ami-c.com) on Java-based technology

Control bus : powertrain, ABS, engine control...– OSEK/VDX initiative (www.osek-vdx.org) on RTOS and

multiplexing– TTP or Flexray initiatives for fault-tolerance (Drive-by-wire)– LIN Local Interconnect Network initiative

AJACS targets the second world

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Specification of USER Functions

Cruise ControlUser Function

Display SpeedUser Function

MeasureSpeed

ReadBrake Pedal

Displayvalue

ReadCC-buttons

EngineControl

CruiseControl

Data flow:Vehicle speed

System input:wheel sensor System output:

Speedometer

Sub-function:Engine control

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Allocation to “ECUs”

ABS Instrument Cluster

Powertrain

Cruise ControlUser Function

Display SpeedUser Function

MeasureSpeed

ReadBrake Pedal

Displayvalue

ReadCC-buttons

EngineControl

CruiseControl

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General Requirements

Car manufacturers – To have more control on the specification of user functions– To protect trade secrets– To reduce integration cost– To reduce bills of material

For the OEMs– To reduce development cost through “generic platforms”

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Engineering Requirements

Subfunctions must be independent and relocatable

This implies– standard communication interfaces– software development methodologies that supports easy

customisation and reuse of software components

Java can help meeting all these requirements !

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Technical Constraints

Typical ECU configurations– Single Chip– 256Kb ROM or Flash– 8Kb to 16Kb RAM

Typical runtime constraints– ~100µs response time for some conditions– Predictability– Overall CPU load from system software < 10%

Closed world– every thing is static

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AJACS Objectives

Specification, Development, Demonstration of– An open technology– Based on Java– For deeply embedded automotive control systems

Industrial viewpoint– Benefit from OO in terms of structuring, reusability, dependability– WORA attributes to some extent, robustness attributes– Support the same kind of real-time constraints which non Java

based ECUs are managing today. – Single chip approach - Small footprint

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Technical Approach. Related Issues

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Run-time Architecture

Architecture of the target software– Application Java classes

use the HIPA API

Note : Multithreadone-to-one mapping– 1 java thread = 1 OSEK

Task OSEK runtime

HIPA APIs

implementationAJACS

runtime

C standard libraries

Application

Language core

HIPA APIs

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Generation Approach

Native code approach– Compiler generates low-level, assembler-like C

Approach :– Front-end : Jikes Java front-end from IBM– Java source code translated into AJACS-Abstract Syntax Tree– AJACS-AST translated into C code

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Specific Technical Constraints

Support of C legacy code– OSEK-Based applications– Drivers (e.g. CAN drivers)

Support current programming practices– OSEK culture– Everything is static

Using Java for system programming– accessing physical memory/registers– bit manipulation– no physical memory rep spec– no typedef

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AJACS Development chain

File edition

JavaFiles

Config.Files

Front-End

Back-end : code generator

Optimization

HIPAAPIs

runtimelibraries

Usual compilation chain : (C compiler, linker, transfer software,...)

Verification

Target

externallibraries

Generatednative code

Generatedconfigdata

Load image

Debuginfo

Nativelibrary Native

library

Javafiles

Intermediate representation

Intermediate representation

OptimizationoptionsProgramming

modelfeatures

Debugger

Support fordebug

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Java Run-time Issues 1

C/Native Interface– Very simple implementation (e.g. direct name matching,

parameters can be only primitive types ...)

Exception management– Currently implemented : backward propagation from Callee to

Caller.

Debugging– Will rely on usual C debugging solution + instrumentation of the

generated code to retrieve original Java source code.

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Java Run-Time Issues 2

Supporting Core classes– directly managed by the compiler

Class initialization– performed at compile-time

Concurrency– threads are mapped directly by underlying OSEK– Java synchronization means not yet implemented

Object ROMization– first step : the user explicitly specifies objects to be ROMized– further investigation : automatic ROMization by code analysis

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AJACS Status

Requirements Specification and Architecture

– HIPA 0.3 Draft– AJACS architecture

Reference Implementation - Jan 2002– Run-time on top of OSEK/VDX– Code generator– ECU platform

Evaluation - June 2002– PSA : body control application– CRF : dashboard application

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HIP/AutomotiveWorking Group

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What is HIP/Automotive

High Integrity Profile– HIP requirements– Static tasking model from Real-time core

High Integrity Profile /Automotive– HIP requirements– Static tasking model from OSEK

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Main orientations of HIP/A

Native code compilation expected– not imposed

Execution of complete applications Static configuration

– all system entities are defined prior to generation– Specific language for configuration purpose

Support for OSEK legacy

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Current Status

Draft 0.3 Harmonisation work with HIP has been started

– a work document has been released in order to identify the common requirements with HIP

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Harmonization in picture

HIP 0.2

HIPA 0.3

HIP 1.0High integrityrequirements

High integrityrequirements

HIPA 1.0

Static task modelderived from OSEK

Other automotiverequirements

Annex:Static task modelderived from Core

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Implementation Aspects

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Class Diagram

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Java: Task 1 structure

public class Task1 extends StaticTask {

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public void work() {EventManager.setEvent (Task2, Event2);

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}

}HIPA service

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HIPA: EventManager Class Implementation

public class EventManager {

public static void setEvent (int task_id,byte mask) /*throws BadIdentifier, BadTaskDef, BadTaskState*/ {

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EventManager.nativeSetEvent(task_id,mask);

}

} Native interface call

Exception management will be implemented

in the next version of the compiler

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C native interface

public native void nativeSetEvent(int task_id, byte mask) of EventManager class is implemented as:

void _EventManager_nativeSetEvent_void_int_byte (char* this,int task_id,byte mask) {

Status=SetEvent(task_id,mask);

}

OSEK service

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CompilationCore class

HIPA class

C compilation

Application class

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Execution

Execution on targetenvironmentGeneration of a binary file with

the usual compilation chain

Download of thebinary file on target

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Technology Availability

Two packages to be available for evaluation PC evaluation

– Compiler– Minimal run-time

68336 evaluation kit– Compiler– AJACS run-time– HIPA run-time– OSEK/VDX– 68336 board with CAN interfaces

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Thank You

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