Lab instructor, 2015-2016 Course Objectives ===== It is extremely important for a student of computing to understand some of the machinedependent aspects of computers, and how they might impinge on embedded software, and on systems software. This course covers the ground from a subsystem-level description of computers (also known as "computer organization"), through programmer-visible aspects of the machines ("computer architecture"), to assembly language issues. As such, the course is a bridge between the hardware and assembly language courses on our curriculum (Digital Systems and Introduction to Computers), and the pure programming courses, such as Systems Programming and Operating Systems. As one of the goals of the course is to enable the student to quickly learn to use any newly encountered architecture, we focus mostly on principles, rather than on a particular machine. Nevertheless, as a case study (and in order to provide hands-on experience), the course will discuss one CISC machine (Intel series 80X86). Machine-specific assembly language, and advanced issues in low-level programming will be the main topic of the exercise sessions. In particular, a special new feature of this course examines malicious programming and how understanding machine code helps us prevent it or detect it. We will examine basic worm-holes, and executable file virus operation techniques, and how to help prevent their attacks. As this course centers on low level, and in order to avoid overlap, this course is now merged with the Systems Programming Lab. The Lab is based on a LINUX platform, and uses the C programming language. As in the architecture part of the course, the emphasis is on low-level programming. Goals of this lab are to introduce issues in low level programming, as well as techniques on how to learn needed information on demand, via hands-on experience. Syllabus Overview ====== Review of basic architecture Machine and assembly languages (generic) The process of assembly and linking Special assembly language programming issues Parameter passing: assembly language and "external" Return addresses and co-routines Traps and interrupts: mechanism and handling Worms and viruses: malicious code and defending against it. Architecture design considerations - CISC vs. RISC Special miscellaneous topics Operating system interface: traps and interrupts, Access to IO devices: display, keyboard, disks, real-time clocks, DMA, Communications (serial and parallel), simple error detection and correction codes (parity, Hamming), handshakes. Topics Covered in the Labs ====== The Lab will be based on a LINUX platform, and use the C programming language. The emphasis is on low-level programming. Goals of this lab are to introduce issues in low level programming, as well as techniques on how to learn needed information on demand. The following topics will be covered via hands-on experience during this course: Low level programming in C. This includes all sorts of "tricks" that emphasizes the power of low-level computing, as an aid to understanding computing systems in depth: Pointers to functions and their applications. Self modifying code and applications. Binary files of various types: structure and processing. Maintaining data structures in files (e.g. pointers to structures, Linux directories). Object and executable files (demonstrated through ELF files). Linking and Loading. Using operating systems services (system calls): Process control: creating and terminating processes, process control, signals. Will be introduced by programming a simple shell. System-level Input/Output: read, write files, file metadata, sharing files. Issues in program development: Debugging programs, and the effect of compound bugs (e.g. various types of memory leaks, compiler bugs). Patching and hacking. 