1、THE ARCHITECTURE FOR THE DIGITAL WORLD,Philippe.R,Embedded Linux for ARM Architecture,Summary,System overview Strategy Technical challenges GNU roadmap Board support Linux vendors Resources,Main Components,Milo (BIOS equivalent) Initialises the board Start kernel execution Based on AFS 1.4.x Kernel

2、Configurable includes drivers and modules Applications Filesystem image (cramfs) Reside in Flash or cross-mounted directory via NFS Imported packages Hardware Integrator AP or CP ARM Core + Logic modules,Linux Kernel,Support for ARM cores with MMU ARM 720, 92x, 102x, 113x Most options are configurab

3、le using graphical tool Pre-defined configurations for selected boards Two main versions: 2.4.x (currently 2.4.19 rmk6) 2.5.x leading to 2.6 kernel (planned end 2003) Availability: base kernel source (open source and DevZone) ARM additional patches rmki (open source: ) ARM

4、specific patches (DevZone),Applications,Filesystem containing system utilities and applications Packages can be selected at build time using configuration tool Import packages publicly available (i.e. Debian) ARM DevZone contains: Pre-built images Tools and packages to build filesystem images,Develo

5、pment Environment,Based on Linux host platforms Use GNU cross compiler (also available on ARM DevZone) ARM Development tools can be used to: Load Kernel images using ARM Debugger with ICE tools Symbolic debug of kernel images or drivers (using breakpoints, trace etc.) GDB used to debug applications,

6、Linux Strategy,Based on open source and standards Contribute new code back to open source Provide support for ARM evaluation boards Add support for new ARM cores (e.g. ARM10 x, ARMv6) Develop and validate new functionality (energy management, security) Used internally for

7、system validation (cores and boards) Partner support via ARM DevZone,Linux Strategy,Work with OEMs creating products using Linux Work with Embedded Linux companies Offer comprehensive support for kernels, applications and development environment ARM DevZone used as focal point of contact ARM connect

8、ed community program,ARMv6 support,Full ARMv6 support with 2.6 kernel Includes kernel optimisations to exploit ARMv6 architecture 2.4 kernel patch to run legacy code Early availability via patches on DevZone Aligned with 2.6 kernel release and hardware availability Used with GNU development toolchai

9、n supporting new v6 instructions (binutils initially),Technical challenges (1),Reduced memory footprint Modular kernel Library size Multiple choices of libraries such as GNU C library. Support for non-MMU cores Linux only runs on cores with Memory Protection Unit uCLinux Adapted version of Linux to

10、run on non-MMU cores Uses different libraries,Technical challenges (2),Thumb support Reduced memory footprint Security Support for encryption Use of specialised hardware features Power management Advanced Configuration and Power Interface (APCI) Intelligent Energy management (IEM)(hardware and softw

11、are support),Technical challenges (3),Symmetric Multi-Processor Synchronization issues Memory coherence Toolchain support Expose kernel resources to the debugger Halted System Debug Running System Debug System profiling Kernel profiling Use Trace Macrocell capabilities,GNU Roadmap,GCC 2.95.3 Stabilized version APCS PE Coff/ Elf Dwarf GCC 3.2.x ATPCS ARM Architecture 5T (VFP) Xscale Next release based GCC 3.x Support ARM Architecture 6,Board support,Main Linux vendors,Montavista