System Integration

1
System Integration

• Raj Rajkumar
• Professor, ECE and CS
• Director, Real-Time and Multimedia Systems Lab
• Co-Director, GM-CMU Collaborative Research Lab
• Carnegie Mellon University
• http//www.ece.cmu.edu/raj

2
Background

• Real-Time operating systems and networking
• Real-time Linux nano-RTOS
• Scheduling theory

3
Example Automotive Control
4
Example Wearable Sensors

• Acceleration, Tilt, Ambient Light, Temperature
  and Audio
• Tactile, Visual and Audio Notification
• Bluetooth and IR Communication
• ARM7 Processor
• 1Mb Flash Storage
• Extensive Power Management
• Frequency Scaling
• Peripheral Power gating

5
The Software Problem

• There is no software problem!
• I must be low on sugar
• We do have a system problem
• The same software in different contexts may be
  acceptable or not
• Depends on the systems needs
• The cost of development and verification
• The cost of failure
• The cost that the customer is willing to bear
• Depends on your system
• How is it different from the other system?

6
The Temptation

• The software has been used before without
  problems
• Therefore, it should work again in my system.

Ariane 5 launch
7
The Greed

• Generation n1 will have different problems than
  Generation 1.

Unintended feature interaction ? Feature creep
8
Its binary, right?
0111010110100110 1010101010110100 1011101001000101

• Multiple levels of operation
• Without failures
• With failures
• One or more failures
• Which failures
• Optimal operation (e.g. sampling frequency)?
• No depends on environment and where we are
• Minimize energy?
• No control energy

9
Solutions

• Decouple wherever possible
• Separate functional correctness from
• Timing correctness
• Replication for fault-tolerance
• Security
• Multiple models at different abstractions
• Capture couplings where they must be
• Capture interactions and dependencies
• Manage couplings automatically
• Generate code

10
Software Infrastructure

• Predictable real-time operating systems

Windows

• We can analyze and validate timing behavior
• Wired and wireless networking
• Multi-hop wireless networking to extend reach

11
Challenges

• Barium injection to see problems and locations
• Testing must think like the car thief and
  explore/exploit openings
• Reverse reasoning from good/bad outcome(s) to
  source(s)
• Model different aspects of system behavior
• Know thy system!

Analyze
Model(s)
Generate
12
Bio
Dr. Ragunathan (Raj) Rajkumar is a Professor in
the Departments of Electrical Computer
Engineering, and of Computer Science at Carnegie
Mellon University where he serves as the Director
of the Real-Time and Multimedia Systems
Laboratory and the Co-Director of the General
Motors-CMU Collaborative Research Laboratory. Raj
obtained his M.S. and Ph.D. degrees from Carnegie
Mellon University in 1986 and 1989, respectively.
He has been conducting research in distributed
real-time and embedded systems for over 18 years.
Since 1985, his work has focused on all system
aspects of real-time and multimedia systems
including operating systems, networking, and
middleware services. His work on priority
inheritance protocols to avoid priority inversion
problems is well known in the research and
practitioner communities. He served as the
Program Chair and General Chair of the 1997/1998
IEEE Real-time Technology and Applications
Symposia (RTAS 97 and 98), respectively. He was
the Program Chair of the SPIE/ACM Symposium on
Multimedia Computing and Networking (MMCN 03).
He is currently serving as the Program Chair of
the 2003 IEEE Real-Time Systems Symposium (RTSS
2003) and the General Chair of the 2004 SPIE/ACM
Symposium on Multimedia Computing and Networking
(MMCN 2004). He has also authored the book titled
Synchronization in Real-Time Systems The
Priority Inheritance Approach, and edited a book
titled Real-Time Operating Systems and
Services. He also is a member of the Steering
Committee of the EmSoft Working Group focusing on
software technologies for embedded systems. He
holds one U.S. patent and has authored over 75
papers in the domain of real-time and embedded
systems. His research interests include real-time
and multimedia operating systems, real-time
scheduling theory, end-to-end resource
management, and systems support for networking.
He serves on the Technical Advisory Board and is
a consultant to many companies in the embedded
real-time systems domain. Dr. Rajkumar is also a
Founder of TimeSys Corporation (www.timesys.com),
a popular vendor of embedded real-time versions
of Linux and Java.