Introduction Synoptic DSML Software Hardware Tool chain

Synoptic: a DSML for On-Board Real-Time Software Design

Conclusions

Alexandre CORTIER J.P. Bodeveix, M. Filali, G. Garcia, E. Morand , M. Pantel, A. Rugina, M. Strecker, J.P. Talpin 18-19 May 2010

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Main concern : On-Board Flight Software

Introduction Synoptic DSML

Satellite System architecture is specialized according to the satellite mission. I Two main subsystems: I

Software

application equipment (specic scientic

instrumentation)

Hardware

I

platform:

ight software, communication devices, thermal

regulation...

Tool chain Conclusions

payload:

Flight software is critical to the success of the mission: I space industries and agencies worked on engineering processes I Goal: increase reliability I Ex: standards on software engineering and on product

assurance (ECSS-Q-ST-80, ECSS-E-40)

BUT: These standards do not prescribe a specic process. I

They rather formalize documents, list requirements of the process and assign responsibilities to involved partners. Alexandre Cortier

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GALS Systems

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

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SPaCIFY Project objectives

Introduction Synoptic DSML

The SPaCIFY ANR (French Research National Agency) exploratory project aims to dene a design process and supporting tools for On-Board Flight Software based on: I Model-Driven Engineering (MDE) I use models as a communication medium

Software

I to benet from tools and techniques of the domain

Hardware Tool chain

I

Formal Methods I multi-clock synchronous paradigm

Conclusions

I model-checking I transformations verications

I

Globally Asynchronous Locally Synchronous System (GALS) paradigm I specication of the services of an executive platform I executive platform supporting distribution, partitioning and

dynamic adaptation (middleware)

The associated tools are built upon the Topcased toolkit. (The Open-Source Toolkit for Critical Systems) Alexandre Cortier

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SPaCIFY Process

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

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Synoptic

Introduction Synoptic DSML Software Hardware

Synoptic is the core language of the SPaCIFY process: I a graphical and textual DSML I provides high-level constructions to handle I multi-layers description (various modeling aspect)

Tool chain

I various granularity levels (iterative and renement

Conclusions

development) I modular approach

I

based on a synchronous semantics I formal and deterministic analysis and verication I renement proof I transformation proof

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Synoptic : multi-layers system specication

Introduction Synoptic DSML

Synoptic is not fundamentally a new language but an integration of dierent sources and concepts. I

Software

Software Architecture : Geneauto approach = safe subset of the Simulink/Stateow modelling language I structural feature: Dataow models (Blocks Diagrams)

Hardware

I behavioral feature: Control Flow models (Finite States

Tool chain

Machines)

Conclusions

I real-time constraints: clock properties

I

Dynamic/Hardware Architecture : AADL approach Architecture Analysis & Design Language I Threads description I platform aspects (components view) I mappings: which component execute which functional blocks ? I I I

I

functional blocks → threads threads → hardware components (processor) ...

Components Models: CCM, Fractal Alexandre Cortier

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Synoptic : multi-layers system specication

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

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Synoptic : functional model

Introduction Synoptic DSML Software

I I

I a

Hardware

I 1

Tool chain Conclusions

Software architecture = blocks/nodes hierarchy A block in a block diagram has :

I I

blocktype blocktype → several implementations

a block type describes interaction ports (interface) dierent kinds of implementations : I I I

dataow : describes functional part automaton : describes behavioral part (modes) external/primitive : black box

Dataow and automaton blocks are mutually nested.

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Synoptic : functional model (block hierarchy)

Introduction

AUTOMATON

Synoptic DSML Software

Etat_1

transition

Etat_2

Hardware Tool chain

DATAFLOW

Conclusions

MACRO−ETAT

AUTOMATON Garde

Etat_1.1

Etat_1.2

Action

Macro−état 1.3

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Synoptic : functional model (block I

Communication ports : in, out, inout event port, data port

Introduction

I Direction :

Synoptic DSML

I Type of ports :

I Properties : periodic, sporadic,...

Software Hardware Tool chain

type)

I

I

ex :  period=10 Hz 

Group of ports : I use to group heterogeneous ports

Conclusions

I

Implicit ports : I I I

reset : re-initialization (boolean port) trigger : block activation (event port) enable : block activation control (boolean port)

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Synoptic : functional model (block

type)

Block type example : 1 Introduction Synoptic DSML Software Hardware Tool chain Conclusions

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

-- declaration of a group of port p o r t group pg_datas

features

IMU_Data : i n data p o r t ; -- abstract descript STR_Data : i n data p o r t a r r a y 4 o f double ; DOR_Data : i n data p o r t a r r a y 4 o f double ; end pg_datas ; -- functional interface declaration b l o c k type SunPointing

features

MTQ_Cmd : out data p o r t a r r a y 3 o f double ; RW_Cmd : out data p o r t a r r a y 3 o f double ; -- port group instance inp2 : p o r t pg_datas  p e r i o d =20 ms  end myInt Alexandre Cortier

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Synoptic : functional model (dataow)

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

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Automaton

Introduction

I

I initial state, nal states

Synoptic DSML

I macro-state

Software

I a state is dened as a block implementation : external,

Hardware Tool chain

States = modes

dataow, automaton

I

Conclusions

Transitions I Guard : boolean expression I Actions of transition I I

I I I

strong transition weak transition

Actions : entry, exit and during actions History Shared blocks

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Synoptic/MW : external variables

Introduction Synoptic DSML Software Hardware Tool chain

The Middleware has to abstract the asynchronous behavior of the system (buerisation,...). Interactions between MW and Synoptic models are handled using external variables concept. I external variables = sources / sinks of signals I external variables types: constants, TM, TC, global variables... I external variables contracts Usage contract

Conclusions

Client 1

Client 2

Synchronisation contract Persistence contract Syntactic Contract

Variable Remote access contract

External variables and associated contracts are used to congure the MW. Alexandre Cortier

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System specication system = hardware + software Introduction Synoptic DSML Software

Structuration of a system (clauses) : I components : hardware / software / dynamic architecture

dataows, automaton, ... device, processor, bus, memory Dynamic architecture : threads : declaration of threads +

I Logical (Functional) architecture :

Hardware

I Hardware :

Tool chain

I

Conclusions

temporal properties.

I I

connections : specication of the connections of hardware components mappings : specication of the deployment of functional architecture → threads → processor signal → bus variable → memory

I functional blocks I threads I I

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Tools chain : Meta-Model of Synoptic DSML

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

I I

Meta-model of Synoptic describe using the formalism ECore ECore = metamodeling architecture in the Eclipse Modeling Framework (EMF) I

more or less aligned on OMG's metamodeling architecture MOF (Meta-Object Facility) Alexandre Cortier

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Tools chain : Textual & Graphical editor

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

I

Graphical editor prototyp (Anyware Technologies) : I based on the

I

EMF/Topcased framework

Textual syntax dened with TCS (Textual Concrete Syntax) I TCS is a DSL dened with a KM3 metamodel I can be used to: I I

parse text-to-model serialize model-to-text

I performed with

a single (bidirectional) specication

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Conclusions

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

SPaCIFY project denes a design process for on-board ight software based on: I Model Driven Engineering I GALS I Formal Methods: Synoptic equipped with a formal synchronous semantics A prototype tool chain based on the Eclipse Modeling Framework: I textual and graphical editor I OCL constraints (TOPCASED) have been encoded to check structural constraints on models I translation into SME (using Kermeta) and Altarica I code generation using the Polychrony platform I verication of the coherence of modes using ARC and MEC (Altarica model-checker ) Alexandre Cortier

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Work in progress (1)

Introduction

Case studies: I Thales Alenia Space use case : prove the utility of using Synoptic models as a unifying and unique design

Synoptic DSML

I structural aspects (deduce CCM model) I behavioral aspects (generate the implementation of CCM

Software Hardware Tool chain

components)

I

Conclusions

Astrium use case : Evaluation of Synoptic for early system engineering phases (Satellites ying in formation) I model translated in Altarica I invariants (coherence of modes) veried using ARC and MEC

I

CNES use case : Control/Command part of a Payload Manager I test the expressivity of the Synoptic language

I test if the components of the middleware can be modeled in

Synoptic I better understand the interconnection synchronous

islands/middleware (external variables)

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Work in progress (2)

Introduction Synoptic DSML Software Hardware

Domain Specic Transformations : I Formal semantics of the language has been encoded in a typed sets Theory using the B Method I will be helpful to validate the existing transformation Synotic

→

SME models

I will be used to the formalization of domain specic

transformations

Tool chain

I

Conclusions

I I

renement transformations model reorganization automatic mapping of functional blocks to threads

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Perspectives

Introduction Synoptic DSML Software

I I

Hardware Tool chain Conclusions

Implementation of a clock calculus for Synoptic Extend Synoptic with the formal concept of contracts (assume/guarantee) I renements

I

Improve the concept of components and blocks I genericity

I I

Improve code generation (modularity) Formal correctness proof and subsequent certication of a code generator I under way in the GeneAuto project

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Thank you.

Introduction Synoptic DSML Software Hardware Tool chain Conclusions

Thank You.

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