1. Embedded Linux Sandeep Sirpatil Graduate Student University of North Carolina Charlotte Feb 7, 2005

2. Contents: What is Linux? What is an Embedded OS ? Features of Embedded OS. Flavors of Embedded OS. Features Linux Development tools Market and applications

3. What is Linux? Red Hat, Debian or Suse? GNU software? Gnome, KDE or Ximian?

4. Linux is … Linux refers to the kernel maintained by Linus Torvalds and distributed under the same name The current version of kernel is 2.6

5. What makes a good Embedded OS ? Modular Configurable Scalable Wide CPU support Device Drivers Small size Etc…

6. Real Time in OS The ability of the operating system to provide a required level of service in a bounded response time. – POSIX standard 1003.1 Hard & Soft Real Time.

7. What makes a good RTOS? Multi-threaded and pre-emptible Must support predictable thread synchronization mechanisms A system of priority inheritance must exist

8. Some Embedded OS flavors VxWorks pSOS QNX Integrity Palm OS Symbian OS Embedded XP Pocket PC Linux

9. Commercial Embedded Linux & RTOS MontaVista Linux Lineo - Embedix Neoware - NeoLinux Red Hat Embedded Linux FSMLabs - Open RT Linux LynuxWorks - BlueCat RT TimeSys - Linux/Real-Time

10. Open source Embedded Linux & RTOS ART Linux KURT Embedded Debian Project uCLinux – For CPU’s without MMU RTAI Etc.

11. Special features of Linux Source code freely available Robust and reliable Modular, configurable, scalable Good support for Networking No runtime licenses Large pool of skilled developers Free software and tools

12. Core features of Linux CPU support (x86, ARM, PowerPC, MIPS,Etc. ) Busses & Interfaces ( ISA, PCI, PCMCA, VME, Parallel, SCSI, USB, IEEE1394, I2C) I/O (Keyboard, mouse, Display) Storage (ATA-ATAPI, DiskOnChip, CFI, RAM, ROM) File Systems (JFFS, FAT, EXT, NFS, Etc.) Networking (Ethernet, IrDa, 802.11x)

13. Architecture of Linux

14. RTLinux A “hard real-time” mini operating system runs Linux as it’s lowest priority execution thread Linux thread completely preemptible Real time threads and interrupt handlers never delayed by non-realtime operations Supports user level programming

15. RTLinux Architecture

16. Development tools Compiler, assembler, linker, etc.. Commercial Open Source.

17. Open Source Tool chain Kernel headers gcc – Compiler binutils – assembler,linker,debugger etc.. glibc – Libraries Patches if any

18. Package version combinations

19. Applications Industrial Controllers Mobiles, PDA, Media Centers. Telecomm and Networking Hardware Automobile Computers Robotics Vision Systems Etc.

20. The Embedded OS market 2004 Market Survey done by www.linuxdevices.com

21. Linux choices - 2004

22. Some hiccups… Competing and/or lacking standards No formalized qualification testing GPL license issues Lack of hardware device drivers

23. References http://www.linuxdevices.com http://www.embedded-linux.org http://embedded.linuxjournal.com http://embedded.com “Building Embedded Linux Systems” – Karim Yaghmour Etc.

24. Thank you!