Embedded Linux Sandeep Sirpatil Graduate Student University of

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

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

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

Linux is … n n Linux refers to the kernel maintained by Linus Torvalds and distributed under the same name The current version of kernel is 2. 6

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

Real Time in OS n n 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.

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

Some Embedded OS flavors n n n Vx. Works p. SOS QNX Integrity Palm OS Symbian OS n n n Embedded XP Pocket PC Linux

Commercial Embedded Linux & RTOS n n n n Monta. Vista Linux Lineo - Embedix Neoware - Neo. Linux Red Hat Embedded Linux FSMLabs - Open RT Linux Lynux. Works - Blue. Cat RT Time. Sys - Linux/Real-Time

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

Special features of Linux n n n n 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

Core features of Linux n n CPU support (x 86, ARM, Power. PC, MIPS, Etc. ) Busses & Interfaces ( ISA, PCI, PCMCA, VME, Parallel, SCSI, USB, IEEE 1394, I 2 C) n n I/O (Keyboard, mouse, Display) Storage (ATA-ATAPI, Disk. On. Chip, CFI, RAM, ROM) File Systems (JFFS, FAT, EXT, NFS, Etc. ) Networking (Ethernet, Ir. Da, 802. 11 x)

Architecture of Linux

RTLinux n n n 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

RTLinux Architecture

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

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

Package version combinations

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

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

Linux choices - 2004

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

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

Thank you!