OEM&Lieferant Ausgabe 1/2018

103 ETAS GmbH www.etas.com Website guidelines typically restrict or forbid. ESDL has no optional braces, no use of statements as expressions, no assignment to loop variables, no automatic switch/case fall-through, no implicit integral promotion, no global variables, no pointers, no goto, no unions, etc. Removing all these pitfalls make ESDL intrinsically safer to use than C. All calculations in ESDL are free from common numeric problems like under- flow, overflow, division by zero, and signed overflow. Out-of-bounds array access is not possible in ESDL: the common buffer overflow problem, seen in many security reports, can- not happen in ESDL. ESDL has an extensible type system that as- signs a name to a type (like a C typedef) but with additional information about what value range is allowed and (optionally) what resolu- tion is needed. For example, in ESDL it is pos- sible to define speed as a real number with a range 0.0 to 260.0 km/h and a resolution of 0.01 km/h. Types can use units, for example meters, degrees or time, etc. Unit compatibility is checked automatically to prevent errors like adding a time to a distance. ASCET-DEVELOPER 7’s code generator uses ESDL type information to select the optimal C type for storage and to generate runtime defensive coding checks to guarantee that val- ues are always plausible. Changes can easily be made at one location in the program and can be systematically applied by regenerating the C code. An added bonus is that review and inspection is easier. And ESDL programs are not polluted with hand written range checks that can make it difficult to understand what a program is really doing. Controlling data access and enabling reuse ESDL is object-based, using classes to manage and control access to data. Objects can be used safely, securely and have known memory bounds. Unlike C++ and Java, ESDL is free from memory leakage problems because there is no dynamic storage allocation. Classes in ESDL also support product line variations without needing to “clone and own” functionality. Variation is possible for: P  Code P  Data initialization P  Memory allocation P  C storage representation (e.g., to switch between a floating-point and a fixed-point) Data consistency in a real-time environment is provided in ESDL using a thread-safe com- munication mechanism called messages. Mes- sages have a clear definition of readers and writ- ers. This prevents undeclared access to data. Conclusion In the complex development environment of increasingly connected vehicles, the flexibility of the C programming language can become a disadvantage. It is too easy for errors to creep into the code unchecked and too time-con- suming and inefficient to remove them later in the development process. When working with C, engineers often spend an inordinate amount of time working around the inadequacies of the C language. With ESDL and the ASCET-DEVELOPER 7 tool- ing, ETAS enables the production of safe and secure C code in a more effective and efficient way. ESDL removes entire categories of poten- tial error sources and ensures that it is easier to reuse software and the generated code be- tween multiple projects. With ESDL, embedded software development has reached a new level of efficiency, safety, and security. n Security gaps can be closed immediately while programming. Company Profile ServiceXpert Gesellschaft für Service- Informationssysteme mbH Frankfurter Ring 211 80807 Munich Germany Phone: +49 89 2444209-0 Fax: +49 89 2444209-99 office@servicexpert.de www.servicexpert.de/en ServiceXpert ServiceXpert, system & software house for commercial vehicle OEMs and suppliers, is established engineer- ing partner for vehicle E/E develop- ment. Thereby ServiceXpert focusses on functions and software develop- ment as well as test & integration to the entire vehicle. With specific know how ServiceXpert engineers develop innovative solutions. The Diagnostics-Centre engineers compile comprehensive diagnostic solutions from development to after-sales service. ServiceXpert assists its customers in planning, implementation and opera- tion of information management sys- tems throughout the product lifecycle. For supporting the after-sales service the company developed modular IT solutions and mobile applications. Advertisement