Home

Code Generation from Cinderella

1. INPUT tid for sjekk END LIST SAVE NONE receive WAIT_SIGNALO if receive tid_for_sjekk SET unsigned int 0 1 timer_standard tid_for_sjekk tank_tom tank_nr amp er_aktiv if er_aktiv amp amp tank_var_tom OUTPUT tank_blitt_tom min tank tank var tom er aktiv tank full tank nr amp er aktiv if er aktiv amp amp tank var full OUTPUT tank blitt full min tank tank var full er aktiv tank varm tank nr amp er aktiv if er aktiv false if tank_var_varm OUTPUT tank_blitt_kald min tank tank var varm er aktiv current state venter else if er aktiv true if tank_var_varm OUTPUT tank_blitt_varm min tank tank var varm er aktiv current state venter break case venter_init_data INPUT init_sm END_LIST SAVE NONE receive WAIT_SIGNAL if receive init_sm GET_SIGNAL_DATA amp min_tank amp tank_nr tank_var_varm false tank_var_tom false tank_var_full false Leiming Chen 65 May 2007 Code Generation from Cinderella SDL to Embedded Platforms SET unsigned int 0 1 timer standard tid for sjekk current state venter break default break void tank_varm natural tank_nr boolean aktiv switch tank_nr case I aktiv switchRead amp tank 1 varm 0 break case 2 aktiv switchRead amp tank 2 varm 0 break default aktiv false break
2. Leiming Chen 69 May 2007 Code Generation from Cinderella SDL to Embedded Platforms switch tank nr case l lamper amp kran 1 break case 2 lamper amp kran 2 break OUTPUT LED_WRITE ENV amp lamper void kran_paa natural tank_nr switch tank_nr case I lamper I varme 1 break case 2 lamper I varme 2 break OUTPUT LED WRITE ENV amp lamper Jr kee tan k styring process end eee kok ol ls k kk Preece EE tanker system block end 2 kkk tanker h ifndef tanker_h define tanker_h define initialisator_pri 5 define initialisator_size 100 define sensormonitor_pri 5 define sensormonitor_size 100 define tankstyring_pri 5 define tankstyring_size 100 define timer_standard 1000 endif Leiming Chen 70 May 2007
3. STARTO void Initialisator_kode void Pid TS_prosess unsigned int tank_nr CREATE TankStyring_kode 5 200 TS prosess OFFSPRING tank nr 1 OUTPUT Init TS TS prosess amp tank nr CREATE SensorMonitor kode 7 200 Leiming Chen 56 May 2007 Code Generation from Cinderella SDL to Embedded Platforms OUTPUT Init SM OFFSPRINGO amp TS prosess amp tank nr CREATE TankStyring_kode 5 200 TS prosess OFFSPRING tank_nr 2 OUTPUT Init TS TS prosess amp tank nr CREATE SensorMonitor kode 7 200 OUTPUT Init SM OFFSPRINGO amp TS prosess amp tank nr STOPO void SensorMonitor kode void Pid min_tank int tank_nr boolean er_aktiv tank_var_varm tank_var_tom tank_var_full TIMER tid_for_sjekk enum Venter init data Venter tilstand Venter init data tid for sjekk NEW TIMERQ while 1 switch tilstand case Venter_init_data INPUT Init SM END LIST SAVE NONE WAIT SIGNAL GET SIGNAL DATA amp min tank Sank nr tank var varm false tank var tom false tank var full false SET 10 tid for sjekk tilstand Venter break case Venter INPUT tid for sjekk END LIST SAVE NONE WAIT SIGNAL SET 10 tid for sjekk tank tom tank nr amp er aktiv if er aktiv amp amp Itank var tom OUTPUT Tank blitt tom min tank tank var tom er aktiv tank full tank nr amp er aktiv Leiming Chen 57 May 2007 Code Generation from Cindere
4. signal ini SIGNAL NEW SIGNAL signal parameter l signal parameter2 5 4 2 Data Definition In the data definition three data types are concerned syntype definition synonym definition and datatype definition only for array The functions supplied here belong to def elem del Leiming Chen 28 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Syntype Definition The syntax diagram of syntype definition is shown in Figure 5 7 syntype lt syntype name gt data type identifier range endsyntype lt syntype name gt Figure 5 7 Syntype Syntax Diagram The syntype belongs to the existing data type When the syntype is invoked the range can be used to specify the other data types for array dcl typedef syntype name data type identifier Synonym Definition As the Figure 5 8 shows the name of the synonym is lt synonym name gt and the data type is data type identifier synonym lt synonym name gt data type identifier expression Figure 5 8 Synonym Syntax Diagram dcl data type identifier synonym name expression Data Type Definition A data type definition introduces a set of values and a set of operators Defining a new data type ordering the operators and making axioms for it is too complex Here only the array data type definition is adopted As Figure 5 9 shows the name of the array is lt array name gt and the two parameter
5. 2 1 2 Features SDL is a modeling language which helps designers express and verify their design ideas in an adequate way This means that the language is expressive and unambiguous it has platform independent operational semantics and adequate support for modularization The objectives of SDL are 1 formal description technique 2 easy to understand both for creators direct users and viewers non constructors of specifications graphical representation 3 object oriented language independent of design paradigm e g functions or object oriented 5 independent of implementation language operating system and hardware Since SDL has evolved into a complete language and gradually achieved the objectives SDL greatly improves the success rate in software building And both the standard text representation can greatly improve the portability of different graphical representation built with different SDL tools The SDL has formed its own design methodology It is shown in Figure 2 1 Other Source Code or Object Code OS Lib Yes Figure 2 1 SDL Design Methodology Leiming Chen 5 May 2007 Code Generation from Cinderella SDL to Embedded Platforms SDL adopted object oriented method in implementing and this can improve the productivity quality and reusability Auto code generation is one of the important approaches to achieve the demands It can raise the level of abstraction at which developers can work becaus
6. int tank nr void init tank io void endif TANK IO H Generated Code tanker c include lt stdlib h gt Leiming Chen 62 May 2007 Code Generation from Cinderella SDL to Embedded Platforms include lt sdl 10 h gt include lt string h gt include tanker h typedef unsigned int natural typedef enum false true boolean typedef unsigned int integer typedef unsigned char character typedef char charstring 20 typedef float duration typedef float time typedef float real Pid initialisator sensormonitor tankstyring SIGNAL tid_for_sjekk init_ts init_sm tank_blitt_tom tank_blitt_full tank_blitt_kald tank_blitt_varm void initialisator_code void void sensormonitor_code void void tankstyring_code void int main void tid for sjekk NEW SIGNAL 0 init ts NEW SIGNAL sizeof natural init sm NEW SIGNALQ sizeof Pid sizeof natural tank blitt tom NEW SIGNAL 0 tank blitt full NEW SIGNAL 0 tank blitt kald NEW SIGNAL 0 tank blitt varm NEW SIGNAL 0 initialisator CREATE Gnitialisator code initialisator pri initialisator size STARTO return 0 Peete EE tanker system block Start E FE oleo oe k os ls ls k k le le REREKEKEKEKE EEK Hi trglisator process Start tk EH ol k k ls ke kk k k k void mut tank io void void initialisator code void Pid ts_prosess natural temp1 natural temp2 Leiming Chen 63 May 2007
7. 9 2 Utube Work c 49 ABBREVIATIONS E 51 REFERENCE fic cccssccississnctecctsoctsscsssetsnsdscssonsssassensdscstonsescssensdecssenssecssensdscseensescsesssacssenseacssenscacsseases 52 Appendix A User Manual ss sssssssesssssssesssosssssssssssosssssssssss ssososssosssoss ssssosssssssoss osssssssossssvs ssssss 54 Execution Steps tildado dani ita da iaa 54 BE ee e ap 54 ren Dt EEN 55 Appendix B Example Tanker ecooeveoseveesevveevvesnnvennnveennveenenvesnnvensnvessevessenvennnnesnavessnnsesnsnesennesenee 56 Manually Written Cod rt aea EE dci 56 Generated Codeine 62 IV Code Generation from Cinderella SDL to Embedded Platforms Chart List Chart 3 1 Existing Code Generators Comparison rsnnnvrrvrnvnnrnnrvrrvvnnnnrnarnrevnvnrvarvrevvevesnrsvrenvennee 19 Chart 7 1 Process DT 44 Chart 7 2 Comparison between Generated and Manually Written Codes 1 45 Chart 8 1 Comparisons between CGFR and Existing Code Generatorg sess 47 Chart 8 2 Comparisons among Alternatives srrrnnnnrnrnvrrvnnrnnnnrrvrnvnnnnenvrrvvnrnernervrsvvnrvesnasvrevvnnnennne 48 Table List Table 3 1 C micro Generated Files eene eerte tenete tino tnnt etin tina noinen 13 Table 3 2 C Advanced Basic Generated Files 14 Table 4 T erg ale 21 Table 5 1Transformation symbols nete tentent cederet teret ori rite p eie 23 Figure list Figure 1 1 Work Principle for COPRAL 2 Figure 2 1 SDL Design Methodology AAA 5 Figure 2 2 System Env
8. Continuos Procedure Call Signa Figure 2 4 SDL symbols General A process instance is created either initially or dynamically with a start symbol When a process instance has been created the execution of the process body starts by the execution of the transition that follows the start symbol The states can determine how the process instance reacts to an input The process states are the only locations where inputs can trigger the transitions Triggers An input is the acceptance of a signal by a process in a certain situation state When a signal is accepted it is also consumed An input symbol connects a state to the actions which the process shall take after consuming the signal mentioned in the input symbol How to store the values is also conveyed with signal inside the input symbol In some cases handling of some signals has higher priority than handling of other signals Signals which take priority in a state are placed inside priority input symbols If a state has both ordinary inputs and priority inputs the first signal in the input port mentioned in a priority input is consumed even if it is not the first signal in the input port Sometimes it is convenient to avoid dealing with a signal while in a certain state Signals which should not be dealt with in a certain state are mentioned in a save symbol They are retained in the Leiming Chen 8 May 2007 Code Generation from Cinderella SDL to Embedded Platforms input
9. break case fyller INPUT tank blitt full END LIST SAVE NONE receive WAIT_SIGNALO if receive tank blitt full kran_av tank_nr varme_paa tank_nr current_state varmer break case vedlikeholder INPUT tank_blitt_tom tank blitt kald END LIST SAVE NONE receive WAIT_SIGNALO if receive tank blitt tom kran_paa tank_nr current_state fyller else if receive tank_blitt_kald varme_paa tank_nr current_state varmer break case venter_paa_tom INPUT tank_blitt_tom END LIST SAVE NONE receive WAIT_SIGNALO if receive tank_blitt_tom kran_paa tank_nr current_state fyller Leiming Chen 68 CMay 2007 Code Generation from Cinderella SDL to Embedded Platforms break case venter_init_data INPUT init_ts END LIST SAVE NONE receive WAIT_SIGNALO if receive init ts GET_SIGNAL_DATA amp tank_nr varme_av tank_nr kran av tank nr current state venter paa tom break default break void varme_av natural tank_nr switch tank_nr casel lamper amp varme 1 break case2 lamper amp varme 2 break OUTPUT LED_WRITE ENV amp lamper void varme_paa natural tank_nr switch tank_nr case 1 lamper I varme 1 break case 2 lamper I varme 2 break OUTPUT LED_WRITE ENV amp lamper void kran_av natural tank_nr
10. it shows variable undeclared if the first letter of state name is lower case errors will be identified when compiling the generated files it shows state name undeclared if variable not declared in the text area used errors will be identified when compiling the generated files it shows variable undeclared if continuous signal exist shows continuous warning if two processes or procedures share the same name in different block errors will be identified when compiling the generated files it shows process name_code redefined When the generated files can not be compiled correctly they can check this error handling and check where the problem is Leiming Chen 55 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Appendix B Example Tanker Manually Written Code tanker c include lt stdlib h gt include lt sdl_io h gt include tank_io h Pid Initialisator SIGNAL Tank_blitt_varm Tank_blitt_kald Tank_blitt_full Tank_blitt_tom Init_TS Init_SM void Initialisator_kode void void SensorMonitor_kode void void TankStyring_kode void void main void init tank 100 Tank blitt varm NEW SIGNAL 0 Tank blitt kald NEW SIGNAL 0 Tank blitt full NEW SIGNAL 0 Tank blitt tom NEW SIGNAL 0 Init TS NEW SIGNAL 1 sizeof unsigned int Init SM NEW SIGNAL 2 sizeof Pid sizeof unsigned int Initialisator CREATE Initialisator_kode 10 200
11. void tank full natural tank nr boolean aktiv switch tank_nr case I aktiv switchRead amp tank_1_full 0 break case 2 aktiv switchRead amp tank_2_full 0 break default aktiv false break void tank tom natural tank nr boolean aktiv Leiming Chen 66 May 2007 Code Generation from Cinderella SDL to Embedded Platforms switch tank nr case I aktiv switchRead amp tank 1 tom 0 break case 2 aktiv switchRead amp tank 2 tom 0 break default aktiv false break RC a process end EE HE e k kk kk k k Pesce kkk kkk kk CaN k styring process Start EH k k kk eoo eee void varme_av natural tank_nr void varme_paa natural tank_nr void kran_av natural tank_nr void kran_paa natural tank_nr void tankstyring_code void natural tank_nr enum varmer fyller vedlikeholder venter paa tom venter init data current state venter init data SIGNAL receive current state venter init data while 1 switch current_state case varmer INPUT tank_blitt_tom tank blitt varm END LIST SAVE NONE receive WAIT_SIGNALO if receive tank blitt tom varme_av tank_nr kran_paa tank_nr current_state fyller else if receive tank_blitt_varm varme_av tank_nr Leiming Chen 67 May 2007 Code Generation from Cinderella SDL to Embedded Platforms current state vedlikeholder
12. At the same time their generated codes can only work with their own supporting libraries So if we choose to use other code generators the REFLEX can not work and the payment for them is a bit heavy Now the better option left is to develop a new and free SDL C code generator It can take the supporting library REFLEX into consideration and generate the corresponding C code If this code generator works it can greatly ease the workload for students and teachers in HIA and reduce the time between system design and implementation I have some research experience in model driven technology This project of code generation just belongs to this field I have learned SDL last semester in the course formal methods It seems SDL is an easy and friendly tool All the related knowledge I posses can support this project 4 2 Decision Making Cinderella SDL is a very useful and user friendly SDL tool it almost provides all the features contained in SDL 92 semantics Cinderella Company also has academic relationships with HIA the students can use Cinderella SDL free in courses I have used Cinderella SDL last semester So I am familiar with it Based on these Cinderella SDL is chosen as the SDL system building environment The Cinderella API is a feature which allows you to invoke external programs from Cinderella SDL This way Cinderella SDL can be extended and customized to accommodate special needs Cinderella SDL itself provides a very usefu
13. Diagram The external syntax for input and transitions after input is shown in Figure 5 17 and Figure 5 18 state name trigger Figure 5 17 External Syntax Diagram1 input transition Figure 5 18 External Syntax Diagram2 Before the process begins create a temporary signal variable to use for storing signal receiving temp sig SIGNAL receive trans INPUT signal identifier1 signal identifier2 endlist receive WAIT_SIGNAL Leiming Chen 32 May 2007 Code Generation from Cinderella SDL to Embedded Platforms GET SIGNAL DATE amp variablel amp variable2 if receive signal identifier1 transition trans else if receive signal identifier2 transition trans else transition trans If the situation happens in procedure the result is like trans INPUT signal identifierl signal identifier2 endlist WAIT SIGNAL GET SIGNAL DATE amp variablel amp variable2 transition trans Save The save symbol is another trigger the syntax diagram of save is shown in Figure 5 19 and the external relation diagram is shown in Figure 5 20 SAVE signal identifier Figure 5 19 Save Syntax Diagram input Save Figure 5 20 External Save Syntax Diagram trans SAVE signal identifier1 signal identifier2 endlist SAVE none 5 5 4 Free Actions The free actions can be separated into two types act
14. Embedded Platforms ABBREVIATIONS RTOS Real Time Operating System UML Unified Modeling Language PR SDL Textual Phrase Representation GR SDL Graphic Representation SDL Specification and Description Language AVR A family of RISC Microcontrollers from Atmel API Application Programming Interface CGFR Code Generation for SDL REFLEX MDA Model driven Architecture QVT Queries Views Transformations ConTraSt A Configurable SDL Transpiler and Runtime Environment SITE SDL Integrated Tool Environment 51 Leiming Chen May 2007 Code Generation from Cinderella SDL to Embedded Platforms REFERENCE 1 SDL history from SDL forum visited Feb 2007 URL http www sdl forum org SDL index htm 2 SDL notation from Wikipedia visited Feb 2007 URL http en wikipedia org wiki Specification and Description Language 3 Telelogic maker of Tau an SDL Design Tool visited Feb 2007 URL http www telelogic com 4 Cinderella SDL Design Tool visited Feb 2007 URL http www cinderella dk 5 SanDriLa SDL Design Tool visited Feb 2007 URL http www sdl sandrila co uk 6 SDL Integrated Tool Environment visited Feb 2007 URL http www2 informatik hu berlin de SITE index html en 7 Code generations from Wikipedia visited Feb 2007 URL http en wikipedia org wiki Code generator 8 MDA from Wikipedia visited Feb 2007 URL http en wikiped
15. can change the user defined the property values in the header file The two plug ins can be put under Cinderella SDL and integrated with it The C source code of the code generators and plug in DLL files can be found on cvs http kildekode hia no in the CGFR folder 8 2 Comparison with Existing C Code Generators Due to the complexity and time constraints the details of SDL elements are not fully expanded The whole system is transformed into one single C implementation file with a user defining header file this is not as good as other C generators since they all have their own generating structure for users to choose And there are several elements in transformation are not considered Only the kernel properties are chosen to be transformed Here we will make a comparison between CGFR and existing C generators The detail information is shown in the chart 8 1 The aspects taken into consideration are integrity 1 simplicity s structure t and user friendly f Leiming Chen 46 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Bl C Advanced Chart 8 1 Comparisons between CGFR and Existing Code Generators 8 3 Comparison with Manually Written Target Code The generated target code can be compiled well It shows that the generated code is correct in logic and semantics However compared to manually written code it is a bit different First is the simplicity Because this tool will transform all the
16. do not suppose to check or change The DLL file which generates header file is config dll the name of the implementation code DLL file is CGFR dll In order to make the CGFR work the steps below should be followed 1 Put the two DLL files into the Cinderella SDL plug in folder Start Cinderella SDL click tools menu a menu list will be found There is a plug in item In the plug in item two items will be found One is called config the other is called CGFR First click the config item a header file will be found at the same location as the SDL file Then click the CGFR item the implementation file will be found at the same location PUB In order to change the process priority and stack size users need to access to the header file change the corresponding items with the identity of the same process name 7 In order to change the timer standard access to the header file change the timer standard item 8 To implement the generated code copy them into the platform and execute them User Notifications Because in the CGFR there are many properties not considered So users of the CGFR need to follow the instructions in order to generate the right code for implementation The listed of constraints need to be noticed are users are not supposed to draw any type constructs users are not supposed to draw any service constructs users are not supposed to draw any operator constructs process can have parameters but they do
17. one following these categories The source syntax diagram with necessary explanations comes first then transformed target C code format with the properties specified in syntax diagram In the transformation specification some of the symbols may be used for structuring the flexibility and simplicity They are listed in the table 5 1 gg the function of the element lt gt name of the element SEY hold keywords DOKN number of the elements is 0 or more Ga number of the elements is 1 or more gt properties belong to element Table 5 1Transformation symbols 5 3 Structural Elements Transformation In this section all the structural elements will be introduced according to the range size which they can in charge of The sequence is system block process and procedure Leiming Chen 23 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 5 3 1 System The syntax diagram of the system is shown in Figure 5 1 system lt system name gt det lem block elem Figure 5 1 System Syntax Diagram The system contains a system heading defining lt system name gt The system also may contain textual definitions in the def elem which stands for definition elements The def elem will be introduced in definition element section The block elem stands for block element which will be introduced later The name of the system is lt system name gt so the generated files ar
18. port The retained signals are available for input in a consecutive state This allows also some priority on signal handling in a receiving process The construct of continuous signal can trigger transitions by some conditions being fulfilled than by the reception of signals It is especially powerful when combined with the imperative operators The continuous signal symbol connects a state to the actions taken if the condition is true In some cases it is useful to combine the power of continuous signals and input for modeling of conditional consumptions of signals This construct is called enabling condition This construct and continuous signal are often used with import and view in order to model the effect on control flow Transition Once a process has been triggered it can perform a series of actions before it enters a next state waiting for a new trigger A sequence of actions constitutes a transition An action can affect other processes or be internal Some of the transitions may not be considered here Task and decision allow data to be manipulated locally and to be utilized for influencing the behavior of the process Task is used to manipulate local information Decision allows the execution of a process to be influenced by data values The execution of the system depends on the existence of initial process but in addition dynamic process creation can be used to represent dynamic population A procedure is a paramete
19. specification in SDL PR to an object oriented C representation The transformation from one high level language to another allows for the configuration of supported language features giving it the name a configurable transpiler The intention is to obtain the object oriented structure and thereby increase the readability and traceability of the generate code This code is compiled together with an SDL runtime environment which was derived by manually transforming the formal semantics of SDL 2000 into C preserving both structure and behavior This provides continuous traceability from the SDL specification to the executing system including its runtime environment Application Areas ConTraSt takes SDL PR file as the source file It means any SDL specification file with text format can be transformed using ConTraSt The application area for ConTraSt is mainly for simulation of the systems To execute the generated C files on real time embedded platform some requirements need to be specified For example the implementation language needs to be C Supporting Libraries High level languages have the same view of the object oriented structure Temporally ConTrasT does not have special supporting libraries to base Generated Files Only C files are generated since the high level transformation posses the object oriented structure User Setting Automatic code generation makes the whole code generation process does not req
20. the behavior des elem starts and set a temporary state for later use enum state Enum state namel state name2 current state state name I e When the process transitions come to a state symbol according to the switch structure based on all the states in the process the direction will be a case fork combined with the state name switch state switch current state case state namel trigger trans break case state name2 trigger trans break Leiming Chen 31 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Default break Procedure Sate The state symbol in procedures has the same syntax diagram used in process However the state symbol itself will not be transformed into target code The state symbol will be used to trigger next transitions State trigger trans 5 5 3 Trigger There are several kinds of trigger symbols In this project input and save will be considered and taken The functions supplied here all belong to trigger trans Input It is different in SDL and target C code In target except input symbol additional functions need to be specified in target codes They are signal waiting function and signal parameters getting function All these functions work together can do the same function in RTOS as in SDL The syntax diagram for input is in Figure 5 16 INPUT signalidentifier variable Figure 5 16 Input Syntax
21. the case of C advanced an application The C advanced C basic SDL to C Compiler handles the majority of SDL concepts according to the definition of SDL 92 Application Areas The same as C micro C advanced C basic can also read the SDL diagram from the drawing panel and extract the elements to transform There are a number of application areas for C advanced C basic SDL to C compiler functional simulation and debugging of protocol specifications debugging of system designs described in SDL generation of applications including embedded system applications with real time characteristics performance simulations and simulation of the behavior behind a user interface prototype Supporting Libraries Unlike C micro library which has a complete SDL kernel for embedded platforms the runtime library for C advanced C basic is used for normal C simulation It is not so high optimized for embedded systems Generated Files Except the implementation C files the C advanced C basic SDL to C Compiler can generate a number of support files These files are in the table 3 2 system header file configure normal characteristics environment header define the environment functions signal file store signals implementation file implementation details Table 3 2 C Advanced Basic Generated Files User Setting The C advanced C basic SDL to C Compiler recognizes a number of directives given mainly in SDL comments Some of the impor
22. updates in 1984 1988 1992 1996 and 1999 Object oriented features were included in the language in 1992 This was extended in the latest version SDL 2000 to give better support for object modeling and for code generation 1 Stability of the SDL language is an important attribute to users and SDL 92 was effectively a superset of SDL 88 Therefore any SDL that conforms to SDL 88 was also with a few exceptions valid SDL 92 However SDL 92 has many advantages in the way that systems can be structured using object features of the language and the most popular tools now support SDL 92 features 1 For SDL 2000 the opportunity was taken to remove some features that were not strongly supported by tools Object modeling in SDL was strengthened and better support given for programming directly in SDL In particular the data model was revised to give such features as global data and referenced data objects The structuring features blocks and processes were harmonized into an agent concept Support for ASN 1 was strengthened so that the use of ASN 1 Leiming Chen 4 May 2007 Code Generation from Cinderella SDL to Embedded Platforms modules with SDL no longer requires any change main body of the language 1 Since 1999 there have been a few maintenance issues of the defining documents but SDL 2000 itself has not really changed The language is being reviewed again starting in 2004 and the major influence is likely to be UML2 0 1
23. 0 including exception handling Code generation errors are reported in the Cinderella SDL in the explorer view Application Areas Different from the ConTrasT Cinderella SDL can take both graphical and textual SDL specification in Cinderella tool and transform it into target C The main application area is simulation Supporting Libraries High level languages have the same view of the object oriented structure it does not need special supporting libraries to base Generated Files Only C files are generated since the simulation does not need special support User Setting Automatic code generation makes the whole code generation process does not require any user special settings Summary SITE also allows for the generation of code that produces MSC when executed The MSC generation feature is decorated with implementation that links back to the SDL model to facilitate execution tracing The SITE code generator supports the environment models like CORBA COM and DLL plug ins However like other C generators to execute the codes on real platforms need to require the platforms have C library support SITE plug in in Cinderella SDL is a commercial version it can transform graphical SDL system There is also a free academic version which can transform textual specified SDL system Leiming Chen 18 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 3 5 Comparison among Existing Code Generators A
24. 23 5 3 1 e EE 24 532 Bokse 25 5 3 3 uro te 26 5 3 4 See e 27 5 4 Definition Elements Transformation sess 28 5 4 1 Signal E e ele EE 28 5 42 Data Definido resis DRE 28 5 4 3 V nable Declaration eie rette re ere re eege eege 30 Code Generation from Cinderella SDL to Embedded Platforms 5 5 Behavior Elements Transtormaton ener 30 5 5 1 MA a a Meese Seis HOP 30 5 5 2 AE 31 5 5 3 VIDS SOT u r 32 5 5 4 Pre ACHON Suie enan e eet eege een deeds 33 5341 Acton S a RR RO RD E RR EE 33 5 3 4 2 TEADSIODSBIQ 5 enit heros nace east ii 35 5 6 e sedeat uum 36 Chapter 6 Transformation Technique e c eere cerne eere eerte sette set tn setae etta esteso se tno seus 39 6 1 Generali a e PRG RR RUE Op ERROR ED RR n NR E der 39 6 2 Overview oFtbecAPL e ette rere erem ee em EE 39 6 3 Element Extract tete tec tee c e e 40 6 4 A n D PC 42 Chapter7 C ug l 43 7 1 Results of Different Stages etre retenti reri y eee rores 43 7 2 Test iExample 2 d ni e her tt CUR A e elegant ori o ege 44 Chapter S A 46 8 1 Major Findings annonsesalg 46 8 2 Comparison with Existing C Code Generators esee 46 8 3 Comparison with Manually Written Target Code 47 8 4 Altemativess tees t a rum ptum ELLE D NIAI n Ee 47 Chapter 9 Conclusion and Future Work e ecce ee eese eene eren esten eee tn esten esteso se eno setas 49 9 1 CONCLUSION Zeien enter EET 49
25. Code Generation from Cinderella SDL to Embedded Platforms SIGNAL receive templ 1 temp2 2 init tank 100 CREATE tankstyring code tankstyring pri tankstyring size ts prosess OFFSPRING OUTPUT init ts ts prosess amp temp1 CREATE sensormonitor code sensormonitor pri sensormonitor size OUTPUT init sm OFFSPRING amp ts prosess amp templ CREATE tankstyring code tankstyring pri tankstyring size ts prosess OFFSPRING OUTPUT init ts ts prosess amp temp2 CREATE sensormonitor code sensormonitor pri sensormonitor size OUTPUT init sm OFFSPRING amp ts prosess amp temp2 STOPO void init tank 1o void natural lamper lamper 0 OUTPUT LED_WRITE ENV amp lamper REREREKEKEE EK Hi tralisator process end HE HE ls dde de kkk ol oe oe e k Je Sensormonitor process Start oo ol kk ol ls ls le void tank_varm natural tank nr boolean aktiv void tank full natural tank nr boolean aktiv void tank tom natural tank nr boolean aktiv void sensormonitor_code void Pid min_tank natural tank_nr boolean er_aktiv boolean tank_var_varm boolean tank_var_tom boolean tank var full TIMER tid for sjekk NEW_TIMER enum venter venter init data current state venter SIGNAL receive current state venter init data while 1 switch current_state case venter Leiming Chen 64 May 2007 Code Generation from Cinderella SDL to Embedded Platforms
26. SDL 2 1 1 History SDL is a Specification and Description Language It is standardized as ITU International Telecommunication Union Recommendation Z 100 The purpose of SDL is Provide a language for unambiguous specification and description of the behavior of telecommunications systems The key features of the language are 1 the ability to be used as a wide spectrum language from requirements to implementation 2 suitability for real time stimulus response systems 3 presentation in a graphical form 4 a model based on communicating processes extended finite state machines Although SDL is widely used in the telecommunications field it is also now being applied to a diverse number of other areas ranging over aircraft train control medical and packaging systems SDL is a general purpose description language for communicating systems The basis for description of behavior is communicating Extended State Machines that are represented by processes Communication is represented by signals and can take place between processes or between processes and the environment of the system model Some aspects of communication between processes are closely related to the description of system structure An Extended State Machine consists of a number of states and a number of transitions connecting the states The machine starts in a transition leading to an initial state The language has been evolving since the first Z 100 Recommendation in 1980 with
27. al enabling condition view 99 cn OOV EA LES spontaneous signal This system service is not complete and several places need to be modified However it supplies a basis supporting libraries for codes generated from SDL diagrams Leiming Chen 11 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 3 Analysis of Some Existing Code Generators The auto code generation from models has been in use for several years There are some code generators exist However most of them are commercial tools and they are not free In this chapter a detailed analysis of these tools will be given In order to have a systematic structure and related subjects of these tools the related areas which will be concerned are 1 application area 2 supporting libraries 3 generated files 4 user setting 3 1 C micro SDL to C compiler C micro SDL to C compiler is developed by Telelogic Tau for code generation It can analyze SDL systems and generate C programs from them The generated code can be compiled on C micro RTOS which is a library with a configurable SDL kernel The C micro Library and the SDL Target Tester target library are not available as a pre linked library but are delivered as source to enable scaling of the kernel The C micro SDL to C compiler handles SDL concepts according to the semantics of the SDL 92 Application Area The Telelogic Tau itself contains the drawing panel in which SDL diagram system ca
28. bedded platform 2 Imported and exported features In target C program to posses variables in different functions is a bit tricky to implement 3 Continuous signal and enable condition Not critical in describing systems We keep other elements and transform them with proper treatments The element mapping from source SDL attributes to target C code will be introduced in next chapter Leiming Chen 22 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 5 Transformation Description 5 1 Introduction To transform source SDL diagram into target C code a detailed mapping from SDL diagram contained features to C functional codes need to be specified In this chapter a detailed description of transformations will be supplied Every element which has been analyzed and considered to be taken is transformed with a detailed description including where it is used and which form it should be like in target C 5 2 Element Mapping According to the element analysis from last chapter all the units in a SDL diagram can be divided into three main categories structural element definition element and behavior element Except the normal categories there is a very common type used in SDL It is expression The expression is used almost in all the elements existing in the SDL so it is separated as an important part and will be given its own transformation section The mapping of each element will be given one by
29. belonging are things we need to check The range size they in charge of have been tested with full correctness The definition elements are not fully distributed according to the scope unit However the interpretation among them has no difficulty It is correct 100 Coming to behavior elements using outgoing functions can supply the passed symbols There are some problems unsolved in this stage Join and connector have not been taken into consider Decision loops are the tricky part to be extracted in right manner It will effect the format of generated code 90 of this stage has been completed Leiming Chen 43 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Tool test After the plug in has been generated it is put into Cinderella plug in folder The name is given CGFR It can generate target file every time it is invoked The working promise is 100 Compile test When the codes are generated they are compiled under WinAvR C compiler At first none of the generated files can be compiled After changing of some attributes all the generated files can be compiled without errors The plug ins have grown into 2 One is CGFR one generates header file with name config The correctness is 100 Implementation test REFLEX has some problem in solving the input signals due to the confusion of different version control Many examples can not be executed on AvR chip with REFLEX based functions In order to
30. create plug in for users and to use the Cinderella SDL API to transform the diagram into codes is much easier than read diagrams directly So it is a good choice to choose Cinderella SDL as running environment to generate the implementation code for based on the REFLEX libraries In this paper Cinderella SDL is used as a runtime environment to transform and compile the system models derived from the formal semantics of SDL 92 into C code with the developed real time operating system for AVR micro chip The name is given as CGFR which means code generator for SDL REFLEX This transformation retains the specified system structure and generates understandable code that is a bit similar to the SDL PR syntax This together with the created real time operating system for embedded platform provides system execution The basic principle for CFGR is in Figure 1 1 SDL REFLEX specification Generatec predefined diagram C program library CGFR q C system E WA p Executabl e program Figure 1 1 Work Principle for CGFR Users of the CGFR are supposed to be the students in HIA for academic study They are supposed Leiming Chen 2 May 2007 Code Generation from Cinderella SDL to Embedded Platforms to have the basic knowledge of SDL and C language 1 3 Thesis definition Cinderella is a tool to display high level SDL specifications In order to execute these specifications they have to be turned i
31. e lt system name gt c and lt system name gt h The lt system name gt c file should contain some basic information such as header files and basic type definitions I system name c include lt stdlib h gt include lt sdl_io h gt include lt string h gt include lt system name gt h typedef unsigned int natural typedef bool boolean typedef unsigned int integer typedef unsigned char character typedef string charstring typedef float duration typedef float time typedef float real def elem del block elem del block elem iden process SIGNAL def elem signal dcl block elem signal del block elem ini process int main void def elem signal ini Leiming Chen 24 May 2007 Code Generation from Cinderella SDL to Embedded Platforms block elem crt process START return 0 j block elem trans I lt system name gt h I ifndef system name h def system name h block elem set process pri block elem process elem set process size define timer standard 100 5 3 2 Block The block elem has the referenced syntax diagram of Figure 5 2 block lt block name gt def elem process elem x procedure elem a Figure 5 2 Block Syntax Diagram The structure of the block elem is almost the same as system The block elem contains a block heading defining the block name The block elem also may contain textual definitions in the def e
32. e exact mapping between the source and target Following this mapping the transformation can be executed fluently After the code generator CGFR has been created the generated codes can be compiled without any errors and implemented on the AvR platform successfully A detailed user manual is provided in the appendix A as well According to complexity functionality and dependency of the C codes needed in our project CGFR can manage designed systems with basic elements Our solution makes it possible for software designers to change the configurations according to their needs 9 2 Future Work As SDL is planned to be a profile of UML 2 0 some of SDL concepts is to be removed and redefined So there is substantially much work to redefine the SDL REFLEX as well as the corresponding code generation we would like to invite programmers to join for further development Based on our work following issues can be interesting for further research 1 adaptation of new SDL elements into REFLEX a more steady REFLEX supported RTOS new Cinderella SDL API functions other ways to simulate the constructs in SDL AE obtain the object oriented structure in transformation Leiming Chen 49 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 6 more elements properties can be added 7 more user defined directives can be added 8 aSDLPR file parser and compiler Leiming Chen 50 May 2007 Code Generation from Cinderella SDL to
33. e of the moving trend towards model based development of tools Now SDL has grown into one of the most successful formal techniques used with widespread usage throughout the software and the telecommunication industries Part of the reasons for its general adoption is its intuitive graphical notation and excellent tool support The tool support typically offers capabilities to analyze design implement and subsequently test systems often using combinations of interrelated notations together with SDL such as Message Sequence Charts 2 1 3 SDL Elements Simply speaking an SDL system can be viewed as process instances which communicate by sending signals to each other or to environment Each single process can be described as an autonomous finite state machine working concurrently with other processes cooperating with them or environment through signals A state is the only location where input can trigger a transition in SDL The process performs transitions depending on the inputs Before the process finally moves to a new state or same state many transitions may occur However SDL has grown into a complete language and many new notations have been introduced into SDL to make it more object oriented The basic components of SDL are categorized and listed below 1 architecture system block 2 behavior processes 3 communication signals and channels 4 data abstract data types Here we will introduce the basic ele
34. ed gc and manually written codes mc from three aspects number of the files nof simplicity s and comparability c Bec Bl nc nof S C Chart 7 2 Comparison between Generated and Manually Written Codes Leiming Chen 45 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 8 Discussion 8 1 Major Findings Before all the work start we made a systematic analyze of some existing code generators By catching the most attractive points in these generators we get to know most of the significant features a code generator needs to take care Then we changed our focus on REFLEX The REFLEX supports some of the SDL notations which can be transformed from SDL directly We tried to find these functions and list them for further usage When comes to the real transformation we try to gather all the elements and classify them into several groups Some of them are essential in describing a system they are kept and transformed with full interpretation In opposite some of them which are not so critical are omitted in order to simplify the project Finally we developed a new code generator which can generate C codes from SDL system diagram specification The codes can be implemented on AvR micro chip with the support from the micro kernel REFLEX The name of the generator is given as CGFR We also designed another plug in Config which generates the supporting header files for implementation code Users of CGFR
35. eerte ener 32 Code Generation from Cinderella SDL to Embedded Platforms Figure 5 17 External Syntax Dagram conc cnncanonnccnncnn ns 32 Figure 5 18 External Syntax Dagram conc onncanennconccnn ns 32 Figure 5 19 Save Syntax Diagram recette titer teret in ree He reete 33 Figure 5 20 External Save Syntax Duagram esee eene nennen 33 Figure 5 21 Output Syntax Diagram essent ener nen rennen enne eene 33 Figure 5 22 Task Syntax Diara ete NEEN EE ERR UNS 34 Figure 5 23 Task Syntax Duaeram non nonncanonnconncnn ns 34 Figure 5 24 Set Syntax Diagram esee nene nen rennen nennen enne 34 Figure 5 25 Reset Syntax Diagram sees nennen en enne ennene p S Keni nennen 34 Figure 5 26 Procedure Call Syntax Diagram sese 34 Figure 5 27 Create Syntax Diagram sicisicecsscecesessieccsssnteersesnteconssoveecsesesseesioivevseselsseesiovvensesicevees 35 Figure 5 28 Decision Syntax Diagram sess eene neen eere 35 Figure 5 29 Decision Question Syntax Diagram esee eene 35 Figure 5 30 Decision Answer Syntax Diagram eese nennen 35 Figure 5 31 Label Syntax Diagramm 35 Figure 5 32 Join Syntax Diagram eoesvorvrrnnrnnnvrrvrennevnsvrnvvevnnsvesvrrvvevnnnvesvrsvvevvnsvasvrsvvevvenvasvrsvvevnenen 36 Figure 5 33 Connector Syntax Diagram sees eene eene 36 Figur 5 34 Stop Syntax Diagram epe eh et Peor ret b uus repentino epe pL Eed 36 Figure 5 35 Return Syntax Diagram tete tet
36. elements and structure within the regulations so even sometime the code can be simplified it would not do such a thing Second is the flexibility It is easy and flexible to define variables and some informal texts in SDL and this can be well transformed manually because system designers know how it comes But to fit for the transformation some additional constraints need to be set like designers need to specify all the variants in text area and etc However in general the similarity of the generated code is very high except for some defined structure as we mentioned in simplicity features 8 4 Alternatives Although we think that the method we used is the most direct and shortest way there are some other ways to generate code from SDL specifications Here we list them as alternatives for further discussion The first method we want mention is parsing the PR SDL specification and generate target C code from that Because PR SDL specification has unique format for one system even their GR form is a bit different it can expand the usage range Independent tool is needed because the source file has no running environment to be based on The other way is to use other existing code generators which are under construction of special development groups These tools are very complete and mature They handle many aspects and the codes generated have been tested and verified for many times However they are commercial version Le
37. ement can be classified into three groups start state trigger and free actions The syntax diagram is shown in Figure 5 12 We will follow this structure to give instructions start action state trigger free action Figure 5 12 Behavior Element Syntax Diagram 5 5 1 Start The start symbol can be found both in process and procedure units Although the symbols between them are a bit different the principle and the internal syntax are the same They can be Leiming Chen 30 May 2007 Code Generation from Cinderella SDL to Embedded Platforms transformed equally The syntax diagram for start is in Figure 5 13 start transition Figure 5 13 Start Syntax Diagram The start symbol itself is transformed to nothing However in the process initiation the start symbol will trigger other transitions until it comes to a state or a stop symbol Start transition trans 5 5 2 State Although the state symbols in process and procedures are the same the way to treat them is different So they need to be classified into two sections Process state The syntax diagram of state symbol is shown in Figure 5 14 and the external syntax diagram is state name Figure 5 14 State Syntax Diagram state name x triggers Figure 5 15 External State Syntax Diagram shown in Figure 5 15 The process states have several places to be set First all the distinguishing states in a process should be enumerated before
38. ements belong to process or procedure Quals To traverse the behavior symbols with the same properties in a scope unit the function traversesymbols symbolfunc 1 1 is used But this function need diagram of the Qual the function q diagram is called to exchange the Qual element to Diagram The function traverseoutgoing is used to check the next symbol this symbol reaches This function is called by symbols If a certain symbol is found for example start or state symbols then this function can be used to check the next symbol The nesting will be used to check the symbols automatically one by one until it comes to a certain situation There are many kinds of behavior element symbols start state trigger and free action Every kind has their own way to select the basic attributes The state symbol has a state name list to be accessed the statenamelist returns the list of state names that is specified in the state symbol If Leiming Chen 41 May 2007 Code Generation from Cinderella SDL to Embedded Platforms starred is TRUE the list of names are those specified in parenthesis after the asterisk character The inputvarlist returns the list of signals specified in the input The signallist returns the list of signals specified in the save symbol In output symbol the outputsiglist returns the list of signals specified to be sent in the output symbol Another function reachable also needs to be invoked to check the destination
39. fter we have analyzed some existing code generators a comparison among them is made This is shown in chart 3 1 We compared these tools from five aspects portability p executable e integrity i structure s and user friendly f le dalda a alad La nt i HC micro MC advanced basic 60 L ConTraSt SITE A0 f 20 F Chart 3 1 Existing Code Generators Comparison Leiming Chen 19 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 4 Design Consideration 4 1 Motivation SDL is a one of the most successful modeling language which helps designers express and verify their design ideas in an adequate way SDL adopted object oriented method in implementing and this can greatly improve the productivity quality and reusability Auto code generation from SDL is one of the approaches to achieve these conveniences In the master topic 30 of 2004 a real time operating system for embedded platforms was built in C This operating system can provide SDL primitives such that an easy transformation from SDL to this operating system is possible Until now the students and teachers in HIA need to draw the SDL system diagram and at the same time write same C code to implement on AVR platforms It doubles the workload for them so the need for a C code generator is urgent and necessary There are already some C code generators exist however as we mentioned before most of them are commercial
40. h allows you to invoke external programs from Cinderella SDL This way Cinderella SDL can be extended and customized to accommodate special needs Typical such add ons can be 1 Various kinds of post analysis tools which checks that certain company specific or methodology specific rules are obeyed 2 Filters which flattens the SDL specification some way for example in order to overcome limitations imposed by other tools 3 Code generators There is a very simple way to invoke the API It is to build a SDL plug in which is written in C and further to be compiled to a DLL file Cinderella SDL can invoke this plug in and adopt the functions to obtain elements from the SDL based diagram 6 2 Overview of the API The Capi is the topmost class representing the API It consists of two parts The internal representation of the concrete syntax and the derived properties for the entities in the internal representation Syntaxtree is the internal representation of the SDL specification Propertiestree is the information derived from the internal representation Propertiestree should be regarded as a representation of the SDL entities on a normalized convenient form In order to take a SDL diagram into parsing the corresponding API tree of the diagram needs to be initialized The Syntaxtree contains the internal representing derived from the concrete syntax Together with Propertiestree the Syntaxtree constitutes the contents of API tree whic
41. h is the root class defining the whole API Inside Syntaxtree spellmap is the list of spellnumbers assigned to the names of the specification This can be used to extract elements using their spellnumbers The Propertiestree contains the properties which are derived from Syntaxtree during analysis Together with Syntaxtree the Propertiestree constitute the contents of API tree which is the root class defining the whole API The most important part of Propertiestree is the dictionaries of the entities defined in the SDL specification There is one dictionary for each Qaulifierelementkind Each dictionary consists of a list of Quals each representing an entity of the given Qaulifierelementkind A Qual contains information about all relevant information for an entity Leiming Chen 39 May 2007 Code Generation from Cinderella SDL to Embedded Platforms The Propertiestree has two important functions The selectqualdict return the first Qual in the dictionary indicated by the Qaulifierelementkind parameter To traverse the whole dictionary apply Qual next until NULL is reached or use traversedict The traversedict Qaulifierelementkind int func Qual applies the function func on each Qual contained in the dictionary indicated by the Qaulifierelementkind If the function returns FALSE the traversal will stop There are some crucial attributes in the API tree they are Qual Diagram and Symbol Any SDL entity that can be defined in a
42. have the verification of the result we redesigned a small and simple supporting header function and use the AvR self brought circuit switch input signals to take place of input signals By doing so we are completely successful in implementing the generated code of an example tanker The result of the generated code has the same effect as the manually written one However due to the time constraints we have not implemented other generated codes The stage can only count 60 Based on the tests we have a line chart 7 1 is made to show the process of the test e compling error s implementation error Feb March April May Chart 7 1 Process trend 7 2 Test Example The example tank is tested and it is fully operational So we will give a brief introduction to this example and the compare manually written codes and generated codes Full code generation and manually comparison are also provided in appendix B Leiming Chen 44 May 2007 Code Generation from Cinderella SDL to Embedded Platforms The tank is auto water warmer It can sense empty full and temperature automatically then it will adopt corresponding actions If the tank is empty water will be injected If the tank senses full water will be stopped and warmer starts to work If the temperature comes to a certain grade it will stop heating and sleep until water cooled or empty Compare chart 7 2 between codes generat
43. he function sur will be used to check if the scope element belongs to another element Definition Element Extraction The elements contained in definition element are signal data type and variable They need separate ways to be selected The signal definition can be extracted from the properties tree directly because the elementkind can be set to SIGNALQUAL So a Quallist of signals in the diagram is selected We just need next function to access them one by one The data type definition can be declared with scopes in any level The elementkind can also be set to SORTQUAL A sortlist will be extracted from the syntax tree However in this project we prefer to extract the data type definition element in scope unit The text symbol for each scope unit needs to be parsed the definitionlist function will return a definition element list The data type definition and variable declaration can be extracted from the definition element list The alt syntypedef alt newtypedef alt synonymdef alt_vardef alt timerdef and alt prsymbol are used to extract different definition elements The next will also be invoked to select the next definition element Behavior Element Extraction Behavior elements are represented as symbols Every behavior element kind has a corresponding symbol kind The function kind can be used to switch the parsed symbol kind This will let every element kind receive proper treatment All behavior el
44. he system creation Processes are the actors of SDL systems An SDL process represents an extended finite state machine Processes can be defined with an initial and a maximum number of instances SDL processes can communicate by means of asynchronous message passing with other processes The SDL process may contain a list of elements and their properties It includes process name Leiming Chen 7 May 2007 Code Generation from Cinderella SDL to Embedded Platforms formal parameters local variables time and timers and the graphical representation of a FSM The behaviors of the process are described in the graphical representation of the FSM In SDL the FSM is extended with data processing Process instances can be created and terminated dynamically A process is activated by means of an arriving signal At the end of a transition the next state is entered Each SDL process maintains a set of intrinsic variables which are of the predefined data type PId Process Identity In the graphical representation FSM provides all details of the behavior of the process FSM is composed of certain process symbols They are shown in Figure 2 4 General Triggers Transition element ie d Process NM EM Input Lo Creation C N Kees State D j Output im y 1 Priority Input EN P Process d Termination Nextstat Decision extstate m P Save Comment lt
45. ia org wiki Model driven architecture 9 QVT from Wikipedia visited Feb 2007 URL http en wikipedia org wiki QVT 10 AVR from Wikipedia visited Feb 2007 URL http en wikipedia org wiki Atmel AVR 11 UML from Wikipedia visited Feb 2007 URL http en wikipedia org wiki Unified Modeling Language 12 How to build DLLs visited March 2007 URL http www codeproject com dll DLL EZ Build EZ Usage asp 13 Bruce Eckel Thinking in C 2nd Edition 2003 14 A Olsen O F rgemand B M ller Pedersen R Reed and J R W Smith Systems engineering using SDL 92 1994 ISBN 0 444 89872 7 Leiming Chen 52 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 15 Cinderella SDL Cinderella SDL API document 16 Telelogic Tau Telelogic Tau 4 2 User s Manual 17 Torstein Wroldsen St le Tveitane A Real Time Operating System for embedded platforms 2004 18 Ingmar Fliegel Rudiger Grammes and Christian Weber2 A Configurable SDL Transpiler and Runtime Environment 2005 Leiming Chen 53 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Appendix User Manual Execution Steps The CGFR is designed as plug ins for Cinderella SDL The plug in is in DLL format There are two DLL files in the CGFR one generates user defined header files like setting priority and stack size for process the other is the real implementation C code which users
46. iming Chen 47 May 2007 Code Generation from Cinderella SDL to Embedded Platforms A comparison chart 8 2 clearly shows their advantage and disadvantages in three aspects cost advantage ca functionality advantage fa and portability advantage pa BIPR Generator DExsting Generator Chart 8 2 Comparisons among Alternatives Leiming Chen 48 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 9 Conclusion and Future Work 9 1 Conclusion In this thesis we discussed and developed a new C code generator CGFR The micro kernel REFLEX will provide the SDL notations support to implement the codes under the real time operating system for AVR micro chip Based on the model driven technology which can enhance the software building we proposed and developed several possible solutions to build the code generator We began our research from analyzing some existing code generators such as C micro C Advanced Basic ConTraSt and Cinderella SITE It is very important for us to study the methods and bright points and adopt them to our project To extract all the necessary elements and their properties out we changed our focus on Cinderella SDL API It is an easy API to use and test All the corresponding functions to the elements will contribute later in the transformation By further studying the API functions we expanded the element range and let them fit into the transformation requirement At last we built th
47. ion and transition end The output set reset task procedure call and create belongs to action The decision join and connection next state return and stop belong to transition end All the functions here belong to transition trans 5 5 4 1 Action Output The syntax of the output is shown in Figure 5 21 OUTPUT signal identifier variable to destination via all path item Figure 5 21 Output Syntax Diagram Leiming Chen 33 May 2007 Code Generation from Cinderella SDL to Embedded Platforms The output in target codes needs to specify the destination process The destination has the format of the destination Pid so it is specified as destination trans OUTPUT signal identifier destination amp variablel amp variable2 Task The task has two formats shown in Figure 5 22 and Figure 5 23 variable expression Figure 5 22 Task Syntax Diagram1 informal text Figure 5 23 Task Syntax Diagram2 trans variable expression informal text Set Reset The se has the format in Figure 5 24 SET timeridentifier expression Figure 5 24 Set Syntax Diagram The reset has the format in Figure 5 25 RESET timeridentifier Figure 5 25 Reset Syntax Diagram trans SET expression timer standard timer identifier RESET timer identifier Procedure call The call specifies the name of the procedure and the parameters In Figure 5 26 procedure na
48. ironment Interaction eeseeseseeseeseeseeeeee rennen enne 7 Figure 2 3 SDL Scope Unit Structure sees nne nre eere 7 Figure 2 4 SDL SYMBOLS inisiasi iiss tite e Eo en eres eo np i heet edo 8 Figure 2 5 Work Principle for Reflex 10 Figure 4 1 SDL Element Structure 22 Figure 5 1 System Syntax Diagram cette tereti rere iter nee eret pene 24 Figure 5 2 Block Syntax Diagram sess eae EEEE E ESTESE a enne 25 Figure 5 3 Process Syntax Dagram conc cnnononn conc on ncnnonnconncnn ns 26 Figure 5 4 Procedure Syntax Diagram esee entere RU ie e na EE CUN Lee ERROR 27 Figure 5 5 Procedure Parameter Syntax Diagram sese 28 Figure 5 6 Signal Syntax Diagram sees eene en etre nennen enne 28 Figure 5 7 Syntype Syntax Diagram non ncn none nnnonncnn ns 29 Figure 5 8 Synonym Syntax Diagram eene nene nennen nennen enne 29 Figure 5 9 Newtype Syntax Dagram conc conoce nn conncnn ns 29 Figure 5 10 Variable Syntax Diagram essent nennen nen eene 30 Figure 5 11 Timer Syntax Daeram rennen eene enne nete nne 30 Figure 5 12 Behavior Element Syntax Diagram sees 30 Figure 5 13 Start Syntax Di gram iisteitee ter terere eere e Eli eroi 31 Figure 5 14 State Syntax Diagram ssorvrrvrnrnnrvrnvrnrnnennsnrnvrernnevesnrrvvennnsvesvrsvvevvesvasvrsvvevvesvasvrevvesvenen 31 Figure 5 15 External State Syntax Diagram conc ener 31 Figure 5 16 Input Syntax Duageram conc on een
49. l plug in folder for users who want to develop their own function program These plug in files are written in C and compiled into DLL extension Leiming Chen 20 May 2007 Code Generation from Cinderella SDL to Embedded Platforms files They can use internal Cinderella API functions to extract all the needed components out It is easier than reading in the SDL text specification and parses it directly So I chose to use C to program and compile the program into DLL extension file as plug in After we have made all the things clear we made a workflow table 4 1 for future work Stage 1 Study Cinderella API and the examples Stage 2 Practice to extract all elements needed Stage 3 Adopt the structure in extraction Stage 4 Compile the generated codes Stage 5 Test code on AVR micro controller Table 4 1 Workflow 4 3 Elements Classification and Analysis In SDL the elements are classified as architecture behavior communication and data four sections However in element transformation this classification is proper In order to give a clear and systematic structure of the SDL elements we try to categorize all the basic and important elements into three main types 1 Structural element These kinds of elements have their own scope diagrams 2 Definition element Elements specified in text symbol 3 Behavior element Elements specified in behavior description area The structural element consists of system block p
50. le name Figure 5 32 Join Syntax Diagram label name transition Figure 5 33 Connector Syntax Diagram trans goto label name label name transition trans Stop The syntax diagram of stop symbol is shown in Figure 5 34 transition stop Figure 5 34 Stop Syntax Diagram trans transition trans STOP Return The syntax diagram is shown in Figure 5 35 expression Figure 5 35 Return Syntax Diagram trans expres sion expr 5 6 Expression The expressions which have been taken into account are infix expression parenthesis expression operator application imperative application and conditional expression They will be introduced separately Infix expression The syntactic form used is the infix form as shown in Figure 5 36 dhrnamic operator monadic operator expression Figure 5 36 Infix expression Syntax Diagram expr Leiming Chen 36 OMay 2007 Code Generation from Cinderella SDL to Embedded Platforms expression dynamic operator expression monadic operator expression Parenthesis expression The syntax diagram is in Figure 5 37 expression Figure 5 37 Parenthesis expression Syntax Diagram expr expression Operator application The syntax diagram is in Figure 5 38 operator identifler expression Figure 5 38 Operator application Syntax Diagram The format depends on kind of the operator identifier belongs t
51. lem process elem defines process elements in a block elem There may be procedure elem exist as well They belong to procedure elements The block in target code does not have practical effect However it will give boundary signs such as SR to inform program readers where codes come to There are a list of block element functions will be transformed del def elem del iden_process process elem iden signal del def elem signal del init process Leiming Chen 25 May 2007 Code Generation from Cinderella SDL to Embedded Platforms process elem ini crt process process elem SCIT set process pri process elem set pri set process size process elem set size trans CR sk sl oko A IEC A A k EEK ERK Dock name Start FE 7 ess s o k k k oe oe le le le le o k ol ol K oe k ls le le to procedure elem implen process elem implen ppal e DTock namez end Bee EERIE ACARI CRAIC IC keck 5 3 3 Process The syntax diagram of process elem is shown in Figure 5 3 process lt process name gt det elema behavior des elem procedure elem Figure 5 3 Process Syntax Diagram A process heading defines the lt process name gt The process elem also may contain textual definitions in the def elem In process scope the behavior des elem stands for behavior elements which will be introduced in behavior eleme
52. lla SDL to Embedded Platforms if er aktiv amp amp Itank var full OUTPUT Tank blitt full min tank tank var full er aktiv tank varm tank nr amp er aktiv if er aktiv if Itank var varm OUTPUT Tank blitt varm min tank else if tank var varm OUTPUT Tank blitt kald min tank tank var varm er aktiv break void TankStyring kode void int tank_nr enum Venter init data Venter_paa_tom Fyller Varmer Vedlikeholder tilstand Venter init data SIGNAL mottatt while 1 switch tilstand case Venter_init_data INPUT Init TS END LIST SAVE NONE WAIT SIGNAL GET SIGNAL DATA amp tank nr varme av tank nr kran av tank nr tilstand Venter paa tom break case Venter paa tom INPUT Tank blitt tom END LIST SAVE NONE WAIT SIGNAL Leiming Chen 58 May 2007 Code Generation from Cinderella SDL to Embedded Platforms kran paa tank nr tilstand Fyller break case Fyller INPUT Tank blitt full END LIST SAVE NONE WAIT_SIGNALO kran_av tank_nr varme_paa tank_nr tilstand Varmer break case Varmer INPUT Tank blitt varm Tank blitt tom END LIST SAVE NONE mottatt WAIT SIGNAL O if mottatt Tank blitt varm varme_av tank_nr tilstand Vedlikeholder else if mottatt Tank_blitt_tom varme_av tank_nr kran_paa tank_nr tilstand Fyller break case Vedlikeholder INPUT Tank_blitt_kald Tank_blitt_to
53. m END_LIST SAVE NONE mottatt WAIT SIGNAL O if mottatt Tank blitt kald varme_paa tank_nr tilstand Varmer else if Tank_blitt_tom kran_paa tank_nr tilstand Fyller Leiming Chen 59 May 2007 Code Generation from Cinderella SDL to Embedded Platforms break tanker_io c include tank_io h include lt sdl_io h gt define define define define define define define define define define tank_1_tom tank_1_full 0x01 0x02 tank 1 varm 0x04 tank 2 tom tank 2 full 0x10 0x20 tank 2 varm 0x40 kran 1 varme 1 kran 2 varme 2 0x01 0x02 0x10 0x20 static unsigned char lamper void tank tom int tank nr boolean aktiv switch tank_nr case aktiv switchRead amp tank 1 tom 0 break case 2 aktiv switchRead amp tank_2_tom 0 break default aktiv false break END tank_tom void tank_full int tank_nr boolean aktiv switch tank_nr case aktiv switchRead amp tank_1_full 0 break Leiming Chen 60 CMay 2007 Code Generation from Cinderella SDL to Embedded Platforms case 2 aktiv switchRead amp tank 2 full 0 break default aktiv false break j END tank full void tank varm int tank nr boolean aktiv I switch tank nr case aktiv switchRead amp ta
54. me procecure parameter Figure 5 26 Procedure Call Syntax Diagram trans procedure name procedure parameterl procedure parameter2 Create Leiming Chen 34 May 2007 Code Generation from Cinderella SDL to Embedded Platforms The process instance is created in the same block as the process in which the create request is interpreted The syntax diagram is shown in Figure 5 27 process identifier Figure 5 27 Create Syntax Diagram trans CREATE process identifier process identifier_pri process identifier_size 5 5 4 2 Transition End Decision The external syntax diagram of decision is shown in Figure 5 28 decision ars wer transtiont Figure 5 28 Decision Syntax Diagram The syntax diagram of decision is shown in Figure 5 29 expression Figure 5 29 Decision Question Syntax Diagram Figure 5 30 Decision Answer Syntax Diagram The answer is shown in Figure 5 30 Assume all the options have the range trans if expressionl range true transition trans else if expression2 range2 true transition trans else transition trans Join and Connection The syntax diagram is shown in Figure 5 31 Figure 5 31 Label Syntax Diagram There are two types out connector and in connector Their symbols are shown in Figure 5 32 and Figure 5 33 Leiming Chen 35 May 2007 Code Generation from Cinderella SDL to Embedded Platforms transition lab
55. ments in SDL step by step In order to provide a complete specification of a given system a SDL system specification needs to be given A SDL system is the outermost agent that communicates with the environment The environment of the system is everything in the surroundings that communicate with the system in an SDL like way in Figure 2 2 Leiming Chen 6 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Environment SDL System 4 Figure 2 2 System Environment Interaction A system is a set of blocks block sets and channels Blocks and block sets are connected with each other or with the environment of the system by means of channels A channel is a one way or two way directed connection It is characterized by the signals that it may carry A SDL system must define the interfaces to communicate with other components It has a hierarchical structure A complete system must contain at least one block A block must contain at least one process or block and blocks and processes must not be mixed in one block It is shown in Figure 2 3 BasicSystem BasicBlock BasicProcess Figure 2 3 SDL Scope Unit Structure A block is a container of processes or of blocks Processes of a block are contained in process sets that are connected by signal routes A block is created as part of creation of the enclosing block or system All blocks are created as part of t
56. ming Chen 9 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 2 2 REFLEX 2 2 1 Overview SDL REFLEX is created as the micro kernel of a real time operating system The micro kernel provides the most essential functions to write programs for embedded computer systems The kernel is especially designed to implement systems described in SDL SDL REFLEX is primary implemented for Atmel s AVR 8 bit RISC microcontroller family and is written to compile with the GNU ANSI C compiler for AVR v 3 3 The working principle for REFLEX is shown in Figure 2 5 Operating system C programs support REFLEX Figure 2 5 Work Principle for Reflex SDL REFLEX is a small portable and efficient pre emptive microkernel for real time operating system It has been designed specifically for resource constraint embedded systems SDL REFLEX controls access to system resources and schedules program processes according to process priority By introducing the process concept the internal system operation is coordinated and synchronization can be performed between processes The processes communicate with each other through signals A signal is actually a message which is sent from one process to another in order to inform the receiver of an event or to send some data Each process has its own FIFO queue for incoming signals in which received signals are stored When a signal is consumed it is remo
57. model driven languages SDL has been evolving to a fairly useful description language offering a multitude of different object oriented features over the past 30 years However not all features are necessarily required to specify SDL systems and especially in embedded systems the resulting waste of resources can be avoided With SDL 2000 a formal semantics based on Abstract State Machine ASM was introduced eliminating the ambiguities that come with the informal language definition Additionally the precise mathematical formalisms of ASMs which are used to describe the formal semantics provide a rigorous basis for Leiming Chen 1 May 2007 Code Generation from Cinderella SDL to Embedded Platforms compilers and runtime environments 1 2 Problem Description Manually writing code with the drawn system in SDL doubles workload so automatic code generation from SDL is necessary because it can greatly ease the complexity and time consumed on this There are already some code generators for embedded systems exist however none of them is designed for AvR micro chip family Since an existing micro kernel SDL REFLEX has been developed to support SDL notations in AVR chip family the need for code generators which can generate code based on the REFLEX libraries is urgent SDL is supported by several commercial tools HiA has academic relation with Cinderella Company Furthermore Cinderella SDL is an easy and useful SDL tool it provides the self
58. n SDL specification has a Qual associated A Qual consist of a number of fields which are common to all entities such as name and defining scope unit It also contains a part which is specific to the entity kind For example the entities which can have a behavior graph associated operators processes process types procedures services and service types have a GraphD in the Qual which contains information about states and transitions The Diagram class represents the diagram No distinction is made between a diagram and a diagram page Those terms both refer to an object of class Diagram A Diagram retains information about e g the kind of diagram the heading symbols of the diagram the contained symbols the semantic descriptor Qual for the scope unit and the corresponding reference symbol for the diagram Even though every diagram page of a scopeunit has the same heading according to SDL separate heading symbols exist for each diagram page This is in order to allow scaling and positioning of the symbols in individual pages The function traversesymbols int func Symbol int allpages int skipheading TRUE traverse all symbols of the diagram For each symbol the argument function func is called If func returns FALSE the traversal will stop and traversesymbols returns If the argument allpages is TRUE all pages of the diagram will be traversed If skipheading is TRUE traversesymbols will skip the heading symbols of page s Symbol rep
59. n be drawn The C micro SDL to C compiler extracts all the properties from the SDL diagram can transform it into C The application areas for the C micro SDL to C Compiler are generation of applications including embedded system applications with real time characteristics and generation of target debug applications The generated code combined with the C micro library is highly optimized which is unavoidable for microcontrollers and real time applications Supporting Libraries The C micro library consists of a configurable SDL kernel together with all the necessary SDL data handling functions The collection of C functions and C modules make up the so called SDL machine The C files which are generated by the C micro SDL to C Compiler can only be used in connection with the C micro Library and the SDL Target Tester It is not possible to validate and simulate the SDL system with the C code generated by C micro as this code is only suitable for Leiming Chen 12 May 2007 Code Generation from Cinderella SDL to Embedded Platforms target applications Generated files There are several steps that must be carried out before the generated implementation files can be compiled and linked together with the C micro Library Together with generated implementation file all the generated files are listed in the table 3 1 below configuration file configure SDL characteristics environment header file define the environment functio
60. nk 1 varm 0 break case 2 aktiv switchRead amp tank 2 varm 0 break default aktiv false break END tank varm void kran paa int tank nr switch tank_nr casel lamper l kran 1 break case2 lamper l kran 2 break OUTPUT LED WRITE ENV amp lamper END kran paa void kran av int tank nr switch tank_nr casel lamper amp kran_1 break case 2 lamper amp kran 2 break OUTPUT LED WRITE ENV amp lamper END kran av Leiming Chen 61 May 2007 Code Generation from Cinderella SDL to Embedded Platforms void varme paa int tank nr switch tank_nr case I lamper I varme 1 break case 2 lamper I varme 2 break OUTPUT LED WRITE ENV amp lamper END varme paa void varme av int tank nr switch tank_nr case l lamper amp varme 1 break case2 lamper amp varme 2 break OUTPUT LED WRITE ENV amp lamper END varme av void init tank 1o void lamper 0 OUTPUT LED_WRITE ENV amp lamper END init_tank_io tanker_io h ifndef TANK_IO_H define TANK_IO_H typedef enum false true boolean void tank tom int tank nr boolean aktiv void tank full int tank nr boolean aktiv void tank varm int tank nr boolean aktiv void kran paa int tank nr void kran av int tank nr void varme paa int tank nr void varme av
61. not effect transformation result the outermost scope can only have one system export and import properties of variables should not appear the first letter of state name should have lower case signallist and signalset should not appear Qe ge ES ON A ARO ss data types are restricted to string and array every variable used in the process or procedure scope need to be specified in textarea na o continuous signal should not be used na N informal texts should follow C format These restrictions need to be followed in drawing the system model in SDL They will show no errors in SDL representations however in transformation they need to be considered as Leiming Chen 54 May 2007 Code Generation from Cinderella SDL to Embedded Platforms restrictions Error Handling In Cinderella these constraints will show no error warnings so when users step into the constraints above the corresponding error handling will analyze these points and give warnings to users These warnings will be presented on the message box of the Cinderella The corresponding warnings users may find in running are 1 2 3 4 5 if type constructs exist show type warning if service constructs exist show service warning if operator constructs exist show operator warning if more than one system exist show system warning export and import errors will be identified when compiling the generated files
62. ns symbol file store symbolic information group file process names implementation file implementation details Table 3 1 C micro Generated Files User Setting The users can set the directives of the generated C code and some other properties of the system It is possible for user to set up full user defined or no separation directives in the organizer s Make dialogue interface Priorities can be assigned to processes and signals using directive PRIO Summary The C micro SDL to C Compiler is a user friendly tool Users can define a structure and the properties of the generated files It take most of the properties into consideration except the restrictions of the C micro itself Many options can be chosen from the users which affect the analysis of the SDL system Furthermore a lot of error checks are performed automatically before code generation starts This makes it possible to improve written SDL specifications before any run time testing must be done The main short coming of using C micro is the cost per license It is not free Leiming Chen 13 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 3 2 C advanced C basic The C advanced C basic SDL to C Compiler is also developed by Telelogic Tau for code generation It can translate your SDL system into a C program that you can compile and link together with a runtime library to form an executable program such as a simulator a validator or in
63. nt A process graph area defines the behavior of a process in a process elem The procedure elem may exist in this scope The process scope may contain procedure element so the generated code will show as a range with the same signs of block element The process element itself will be transformed to a C function without return values There is also a list of functions in process element iden PID lt process name gt ini void lt process name gt code void Leiming Chen 26 May 2007 Code Generation from Cinderella SDL to Embedded Platforms EE lt process name gt CREATE lt process name gt code lt process name gt pri lt process name gt stacksize implen fA AH AAA ee Aer sar E E ERICA TIAA I A IACI AC procedure elem ini void lt process name gt def elem var dcl def elem dcl behavior des elem enum state behavior des elem temp sig behavior des elem start behavior des elem switch state procedure elem implen PAR ARIAT TI p rocess name gt edP set pri define lt process name gt pri 5 set size define lt process name gt stacksize 100 5 3 4 Procedure The syntax diagram for procedure elem is shown in Figure 5 4 procedure lt procedure name gt fpar procedure parameters def elem behavior des elem Figure 5 4 Procedure Syntax Diagram A procedure heading defines
64. nto C code In the master topic 30 of 2004 a real time operating system for embedded platforms was built in C This operating system provides SDL primitives such that an easy transformation from SDL to this operating system is possible This task is to use this SDL operating system and to generate code directly and automatically from the Cinderella SDL tool and or the Eclipse SDL plug in produced at HiA The restrictions in the operating systems have to be taken into account and a mostly direct transformation is to be generated If possible the code generation is to be given in a high level formalism like QVT 1 4 Delimitation In this project we try to build a code generator which can generate code automatically from the SDL diagram designed system The code will be implemented with the support of REFLEX The support functions of REFLEX are not in our concern If some functions do not support the implementation or even are not exist we need to find other ways to solve not to change REFLEX The instructions in user manual shows how to compile and execute the generated code on AvR micro chip however the tool itself will not make the generated files executed automatically This tool is a pure code generator without any extra support Users who want to use it need to implement or change other steps by themselves Leiming Chen 3 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 2 Background 2 1 Overview of
65. o The operators need to be changed are or and and They will be changed to II amp amp and strcat expr expression operator identifier expression strcat expressionl expression2 Imperative operator The situations considered in imperative operator is shown in Figure 5 39 PID expression now any actrve expression call procedure identfier Figure 5 39 Imperative operator Syntax Diagram expr Pid SELF SENDER PARENT OFFSPRING bool ACTIVE TIMER timer name procedure name procedure parameterl procedure parameter2 Conditional expression The syntax diagram is in Figure 5 40 if expression then expression else expression fi Figure 5 40 Conditional expression Syntax Diagram expr Leiming Chen 37 May 2007 Code Generation from Cinderella SDL to Embedded Platforms iflexpressionl fexprssion2 else expression3 Leiming Chen 38 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 6 Transformation Technique The last chapter gives a detailed element mapping from source SDL diagram properties to target C code In this chapter we will illustrate how to make the transformation work In this introduction the structure in analyzing elements will be kept 6 1 General This project takes Cinderella SDL as running environment so the API of Cinderella SDL is invoked The Cinderella API is a feature whic
66. oOLEN 2 To a nA E T E e o Oniversity Code Generation from Cinderella SDL to Embedded Platforms by Leiming Chen Thesis in partial fulfilment of the degree of Master in Technology in Information and Communication Technology Agder University College Faculty of Engineering and Science Grimstad Norway May 2007 Code Generation from Cinderella SDL to Embedded Platforms Abstract SDL Specification and description language is increasingly adopted by many companies and researchers Its simplicity and object oriented structure can greatly ease the workload for them However the lack of concretization makes SDL not applicable when it comes to real world implementation AvR is a micro controller which can be a platform to carry out real world implementation The micro kernel REFLEX of the AvR operating system adopted many SDL features Here I present a new code generator which can transform SDL systems into executable C programs It is built specially for SDL REFLEX which is a micro kernel for the real time operating system of AVR We analyzed some existing code generators like C micro C Advanced Basic ConTraSt and Cinderella SITE Then we gathered their advantages and promoted them into our solution All the components which are helpful in building systems have been analyzed and classified only necessary elements are kept in the transformation We also provide the corresponding techniques used in the tran
67. of the signal The question returns the expression which is specified inside the decision symbol Expression Extraction Expressions also have several kinds the same as symbols every kind has its own functions can be invoked to check the wanted attributes First the alt kind function is used to move the expression to the right type Then different functions can be called directly For example in infix expression three functions lexpr infixop and rexpr will separately get the expressions and operators The most basic and useful function is based on Id class The class Id represents the information that is associated to an identifier It consists all the information in the indivisible component especially for name function to get name of the component 6 4 Principle Then the techniques used in the transformation belong to model driven techniques It parses the attributes of the SDL diagram represented system and takes them by building the syntax tree of the system The work principle can be shown in Figure 6 1 Designer defined SDL syntaxtree syntaxtree SDL graphical Designer defined representation representation Figure 6 1 Work Principle for SDL API Leiming Chen 42 May 2007 Code Generation from Cinderella SDL to Embedded Platforms Chapter 7 System Test 7 1 Results of Different Stages To obtain the correctness of the different steps in this project we try to divide the time into several periods and ve
68. pt a more visual automated and reliable development process Its capability for generating code from object models offers additional help for keeping pace The model driven methods can help developers analyze and understand a system in a great extent In model driven technology an important proportion to reduce the complexity of the rapid development is using software automation tools Design automation in general needs a formal system description to capture both functional and non functional requirements and then model based code generation can produce application target code automatically from graphical models of system behavior or architecture Since a lot of advantages have been found in using this development tools are moving to model based development gradually to raise the level of abstractions However until now the model driven methods have a common bottleneck lies in software automation Because of this shortcoming the benefit of object modeling can barely live though the entire products life circle without the automatic code generation The pressure from customers tends to sharp the trend of changing the source code directly resulting in out of date models Generating code from object models still retains less use Model based code generation continues to be a long term trend in development tools However as time goes on the enduring nature suggests that model based code generation is inevitable As one of the most successful
69. re ner eet eese aerea e soo teer e eo E oe en e kns pons eaae re eee a eo GeE 1 1 1 Generali asini deere ee a DR eee E 1 1 2 Problem Desci puois dure sena eS EEE eben eee dee ies 2 1 3 RRE el e E 3 1 4 DIE Ee EE 3 Chapter 2 ASA oen Co Up esto rouen Co tope ege a nep e oes ssis covered oe HUS 4 2 1 Overview ORS DL nitet tetti nitet aiite nien 4 2 1 1 lei EE 4 2 1 2 SAUS Aid dd ds 5 2 1 3 SDL Elements iii ai 6 2 2 REFLEKS 10 2 2 1 IERENS Ode eet eer 10 22 Kemer Beatures iio eniti ete ettet ae n ea 10 Chapter3 Analysis of Some Existing Code Generators eee eeee creen eerte eene 12 3 1 C micro SDL to C compiler nissernes eirin sirs ipi asier seres 12 3 2 C dvaneed E ner ede c E e i ER ees 14 3 3 COM sata 16 3 4 Cinderella SITE ra e a e a 18 3 5 Comparison among Existing Code Generators esee 19 Chapter 4 Design Consideration eee eee e cree creen seen e eene ee tn setas etta esten seen esteso seus 20 4 1 IM OU ALON o tectus the RTS 20 4 2 Decisi n Making casi iit do eR Eh RT EE 20 4 3 Elements Classification and Analysis ssrronnrnnrnrrnrrvnnrnnrnrnvrevnnrnernrsvrernnevesvrsvvesvennee 21 Chapter 5 Transformation Description crece eene eren eerte e ette netto netta esten ese tne se eno seus 23 5 1 else te te ser 23 5 2 Element Mappttie ie RD ep n a tp en FP 23 5 3 Structural Elements Transtormapon conan conan nncnnnnos
70. resents an SDL symbol The function uniqueid is the unique identity of the symbol within the linked file or specification in which it occurs The identity is persistent to save and open The traverseoutgoing int func Symbol Symbol traverse all symbols having the symbol as originating endpoint For each symbol the function func is called with the symbol as parameter The traverseincoming int func Symbol traverse all symbols having the symbol as destination endpoint For each symbol the function func is called with the symbol as parameter The Symbol has some class members which can be used to specify for a particular symbol 6 3 Element Extraction The order for element extraction is structural element extraction definition element extraction behavior element extraction and expression extraction Structural Element Extraction The function selectdictqual elemtkind invoked By setting the elementkind the properties for this kind of structural element can be extracted one by one To extract the scope units system block Leiming Chen 40 May 2007 Code Generation from Cinderella SDL to Embedded Platforms process and procedure the elementkind needs to be set to SYSTEMQUAL BLOCKQUAL PROCESSQUAL and PROCEDUREQUAL Every time invoking the function one Qual is extracted out The next function is used to select the next one In the transformation the belonging relationships of different scopes need to be checked T
71. rify the results achieved at that time Component extractions This is the first stage After the analysis of the elements of the SDL system necessary components are classified and marked with highest priorities The structural element definition element and behavior element are tested one by one The system block process and procedure can be extracted with full properties it possesses The name contained unit unit belongs to and parameters are extracted 100 correct The definition elements taken into account are signal definition data type definition and variable declaration Signals can be selected easily with full properties Data type define three basic new data types they have limitations in showing presenting some properties in target C code The variable declaration enjoys the full interpretation as signals In this section separate extraction can be achieved 100 However predictable risk of property failing exist Almost all the behavior element symbols can be extracted with rather exact precision Two kinds of symbols have problem The destination of the output signal and relationship between decision question and option answer are still under construction The completeness is 90 Structural extractions After we know how to extract information from a single unit the connection among them and the reassembling the structure in target code are the trickiest things Within structural elements their relationships of
72. rized part of a behavior graph with its own local scope This implies that control can only return from a procedure by means of the return construct The procedure can be used as an action or part of expression with procedure call symbol A stop symbol indicates completion of a process instance The process instance ceases to exist after executing a stop The signal instances in its input port are thereafter discarded Signals are the primary communication mechanism in SDL They may carry data by means of parameters All signals to and from the environment are declared at system level Signals can be defined inside a block thus only visible in the block If there are several possible receivers of a signal the signal will be delivered to an arbitrary receiver SDL data is based on abstract data types An abstract data type defines a type of data object by its functional properties i e by a set of operations applied to it In SDL data types are called sorts Variables can only be declared in processes and there are no global variables In SDL inheritance and generics are supported If you want to define a new data type you should set the constants and a set of values operators and axioms There are many predefined data types in SDL After all the basic elements have been introduced it is easy to find that SDL is a rather suitable and complete language to describe systems It can greatly ease the software building engineering Lei
73. rocess and procedure diagram elements In definition element field signal definition data definition and variable declaration will be found Behavior elements are used to specify the behaviors of process It contains symbols which composite the behaviors of the process They are classified as start state trigger and free action There are still some detailed categorizations left We will shoe the whole element structure in Figure 4 1 Leiming Chen 21 May 2007 Code Generation from Cinderella SDL to Embedded Platforms element A Strutual element Definition element Behavior element A A A d emn start system Signal definition state syste block block Data type definitior State trigger block input block process i i H process Variable declaration I SES transition process decision procedure procedure Join and connector A L Newtype definition stop output task return create Setireset cal Figure 4 1 SDL Element Structure Syntype definition Synonym definition procedure In order to simplify the difficulty of the projects some of the features are not taken into consideration they are listed below 1 Constructs They are not so critical in building a system especially for em
74. s are index data type index dt and element data type element dt newtype arr ay name index data type element data type endnewtype lt array name Figure 5 9 Newtype Syntax Diagram The index data type no stands for the range number of the index data type normally the index data type is syntype data dcl typedef element data type array name index data type no Leiming Chen 29 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 5 4 3 Variable Declaration The variable declaration includes two categories variable definition and timer definition Variable Definition A variable is defined by a variable definition A number of variables may be declared in a single variable definition construct The syntax diagram is shown in Figure 5 10 del lt variable name gt data type identifier expression 3 Figure 5 10 Variable Syntax Diagram var_dcl data type identifier variable name expression Timer Definition A timer definition is the declaration of a timer instance in a process or service In the timer definition the lt timer name gt forms the defined timer The syntax diagram is shown in Figure 5 11 Timer lt timer name gt Figure 5 11 Timer Syntax Diagram var del Timer timer name NEW_TIMER 5 5 Behavior Elements Transformation Behavior description provides all details of the behaviors of processes As we mentioned before the behavior el
75. sformation One test example which is frequently used in literature has been executed on AvR platform The name of the example is tank We give the name CGFR code generator for SDL REFLEX to the generator and Config to the supporting header generator They can be integrated under Cinderella SDL as plug ins Keywords code generator embedded platform plug in transformation CGFR SDL Code Generation from Cinderella SDL to Embedded Platforms Preface This thesis was written for Agder University College Faculty of information and communication technology The work has been carried out in the period January 2007 and May 2007 First of all we would like to thank Professor Dr Andreas Prinz our supervisor at Agder University College for excellent supervision and guidance throughout the project period The thesis has been developed in co operation with Cinderella Company in Copenhagen Denmark In this context we will also thank our supervisors Anders Olsen Paul B Anderson and Torstein Wroldsen Finally we would like to thank Head of Studies Stein Bergsmark for his contributions Grimstad May 2007 Leiming Chen Code Generation from Cinderella SDL to Embedded Platforms Table of Contents E ee d I A LE E II Table of OC III Chart E V Table List qu V Fipure list RO V Chapterl Introduction eere eeree eret tetro ee
76. tant ones are listed here selecting File Structure for Generated Code Directive SEPARATE specifying Names in Generated Code Directive NAME assigning Priorities Directive PRIO Summary Leiming Chen 14 May 2007 Code Generation from Cinderella SDL to Embedded Platforms The C advanced C basic SDL to C Compiler is also user friendly and easy to use Users can define the structure of the generated code and some other properties as well There are some other features for them The partitioning concept is a way to divide one SDL system into several applications As a special case this also means that it is possible to simulate and validate selected parts of a system The difference between partitioning and separation should be noted The partitioning feature is a way to select the parts of an SDL system which should be handled while the separation feature is a way to select the file structure for the generated files However C advanced C basic is not designed specially embedded platforms the generated codes can compile smoothly if connected with libraries Since the resource consuming and stack size which are of crucial importance to RTOS are not considered it is not 100 suited for embedded platforms Another shortcoming is that it is not free as well Leiming Chen 15 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 3 3 ConTraST ConTraSt is a configurable C code generator that provides a mapping of SDL
77. te eere nte evene peres 36 Figure 5 36 Infix expression Syntax Diagram conc cnnennconconn ns 36 Figure 5 37 Parenthesis expression Syntax Duageram eene 37 Figure 5 38 Operator application Syntax Diagram seen 37 Figure 5 39 Imperative operator Syntax Diagram seen 37 Figure 5 40 Conditional expression Syntax Diagram esee 37 Figure 6 1 Work Principle for SDL AP 42 VI Code Generation from Cinderella SDL to Embedded Platforms Chapter 1 Introduction 1 1 General From the very early stage of the computer technology until now tremendous accelerations have been made by software engineers regarding the development time and language complexity for the different programming languages Nowadays in order to survive in this fast paced and competitive world manufacturers are forced to deliver more complex and complete systems in less time with fewer staff and higher quality This increases the responsibility for software designers to design and deliver these systems as efficient as possible At his time the abstraction of languages has increased from assembly language to high level languages up to graphical models and the abstraction has moved from the system solution space toward the application problem space This trend can increase productivity fulfill the need for constructing larger applications and understanding complex systems In this climate model driven development is used to ado
78. the procedure name and procedure parameters The procedure elem also may contain textual definitions in the def elem A procedure graph area defines the behavior of a procedure in a behavior des elem Unlike process element procedure element can have return value in its transformed C function The syntax diagram of procedure parameters is shown in Figure 5 5 Leiming Chen 27 May 2007 Code Generation from Cinderella SDL to Embedded Platforms procedure parameter return return data type Figure 5 5 Procedure Parameter Syntax Diagram ini procedure parameter gt return data type procedure name procedure paramters gt procedure parameterl procedure parameter2 implen Ah RRR RRR EEE EERE REE ERE lt nrocedre namez start tll ol ol oe oe le ls le le k k k k kkk K k procedure parameters return procedure name procedure paramters pars def elem dcl behavior des elem start BREE RRR ER ERR EE EAR ERE REE ERE lt nrocedre namez en Ke 5 4 Definition Elements Transformation The text symbol contains def elem local to the scope it belongs to It has three categorizes signal definition data definition and variable declaration 5 4 1 Signal Definition The syntax diagram for signal definition in the def elem is shown in Figure 5 6 signal lt signal name gt signal parameter Figure 5 6 Signal Syntax Diagram signal del SIGNAL lt signal name gt
79. uire any user special settings Summary The feature in transformation is to exploit and retain the given object oriented structure of SDL PR allowing for a successive traceability from an SDL specification to its C representation This is achieved by the inheritance of C classes each representing one specific SDL 96 object Most of these objects such as plain data types or signals can be described by simple classes with parameters while processes with corresponding types are represented by the use of template classes Therefore a complete SDL system specification can be transformed into Leiming Chen 16 May 2007 Code Generation from Cinderella SDL to Embedded Platforms an object oriented C representation hierarchical composition of classes is used to implement the visibility of definitions and variables which also allows for the application of identifiers with scope information As a C transpiler ConTraST can simulate the SDL system with its runtime environment in an efficient way However to execute the codes on real platforms need to require the platforms have C library support The ConTraSt is a free code generator Leiming Chen 17 May 2007 Code Generation from Cinderella SDL to Embedded Platforms 3 4 Cinderella SITE Cinderella SITE is a code generator that generates ANSI C from SDL It is closely integrated with the Cinderella SDL Cinderella SITE supports most of SDL 96 plus selected parts of SDL 200
80. ved from the FIFO queue All the actions a process performs are usually responses to received signals All interaction with the SDL REFLEX microkernel is through a set of system services 2 2 2 Kernel Features Down below is a list of the system services mapping that has been designed to reflex the behavior of SDL These are only the most prominent features Leiming Chen 10 May 2007 Code Generation from Cinderella SDL to Embedded Platforms CREATE gt CREATE process_code process_priority process_stacksize INPUT gt INPUT signall signal2 SIGNAL gt SIGNAL number of arguments argumentl OUTPUT gt OUTPUT signal destination argumentl TIMER gt NEW_TIMER SET gt SET duration TIMER RESET gt RESET TIMER ACTIVE gt ACTIVE TIMER STOP gt STOP SAVE gt SAVE signall signal2 START gt START PID gt SELF SENDER PARENT and OFFSPRING SOOO AO oUm A ID 1 na Rh o N In addition to the previously mentioned functions which are described in SDL there are more functions in SDL REFLEX which isn t described in SDL but is critical to completely implement the behavior of SDL 1 WAIT SIGNALQ 2 GET SIGNAL DATA parameterl In this REFLEX supporting service there are several SDL features are not supported they are listed below system structure communication channels signal routes constructs package type service context parameters imported exported continuous sign

Code Generation from Cinderella

Contents

Download Pdf Manuals

Related Search

Related Contents