FemtoLinux allows real-time Linux applications to run in kernel mode for improved performance and latency. It eliminates system call overhead, supports ARM, MIPS and PowerPC, and makes it easy to port applications from RTOS environments to Linux. Benchmarks show up to 30% improvement in networking performance and 200% improvement for memory-intensive applications. FemtoLinux provides a kernel patch, library patches, and services including porting, training and development environment customization.

1. FemtoLinux
Making real-time Linux applications a reality
www.femtolinux.com
info@femtolinux.com
FemtoLinux. Making real-time Linux apps a reality.

2. FemtoLinux in a Nutshell
● Allows execution of applications in kernel mode
● Applications can access hardware and kernel resources
● System call overhead is eliminated
● Huge performance and latency improvement
● Effortless porting from legacy RTOS
● Geared towards real-time and embedded systems
● Supports ARM,MIPS and PowerPC architectures
● Fully working system
FemtoLinux. Making real-time Linux apps a reality.

3. Features
● Allows to run regular Linux processes in kernel
mode
● Some processes can run in kernel and some in user mode
● The same process can run in either kernel or user mode
● No application modifications are required
● All user mode libraries are available
● C, C++ and all other languages are supported
FemtoLinux. Making real-time Linux apps a reality.

4. Features, continued
● FemtoLinux applications have no restrictions
● Can access kernel resources
● System call overhead reduces to a function call
● Can read, write and allocate kernel memory
● Can access hardware resources
● Access HW, including CPU, registers
● Enable/disable interrupts
● Etc...
FemtoLinux. Making real-time Linux apps a reality.

5. FemtoLinux vs. VxWorks 5.x/6.x
● VxWorks 5.x has flat memory model
● Tasks communicate directly with kernel
● Low latency and low system call overhead
● VxWorks 6.x adds (optional) memory protection
● Process based programming model
● Memory protection
● Significant system call overhead
● FemtoLinux adds (optional) flat memory model to Linux
● FemoLinux processes run in kernel mode
● Similar to VxWorks tasks
FemtoLinux. Making real-time Linux apps a reality.

6. FemtoLinux can be used to
● Significantly improve embedded application
performance
● Improve embedded application latency
● Easily port RTOS applications to Linux
● Create zero-copy networking applications
● Much more!
FemtoLinux. Making real-time Linux apps a reality.

7. Porting From RTOS to plain Linux
● RTOS applications tend to be monolithic
● No separation between driver and application
● Porting to RTOS from Linux requires
architectural changes, not just API adaptation
● Huge development effort
● Kernel-user communications overhead
● Hard to support both Linux and RTOS
● Risk
FemtoLinux. Making real-time Linux apps a reality.

8. Porting from RTOS to FemtoLinux
● Similar to porting from one RTOS to another
● No architectural changes
● Faster time-to-marker
● Smaller risk
● The same code base can run on Linux & RTOS
● With thin OS abstraction layer
● Less support and QA issues
FemtoLinux. Making real-time Linux apps a reality.

9. Benchmarks
● Benchmarks performed on ARM9 based system
● 20% system call latency improvement
● Measured for frequently used gettimeofday(2) call
● 30% networking performance improvement
● Measured using standard iperf without any modifications
● Not including optional memory copying optimizations
● Up to 200% improvement applications that frequenyl
copy memory to/from kernel (most networking apps)
● Requires minor changes to application
FemtoLinux. Making real-time Linux apps a reality.

10. FemtoLinux Delivery
● Software ● Services
● Modified Linux kernel ● FemtoLinux porting to
(or kernel patches) client HW
● Modified eglibc library ● Development
(or patches) environment
● Development adaptation to client
environment – full needs
cross compiler ● Application porting to
toolchain FemtoLinux
● Training
FemtoLinux. Making real-time Linux apps a reality.

11. For more information visit our web site at
http://www.femtolinux.com or contact us by email
at info@femtolinux.com
FemtoLinux. Making real-time Linux apps a reality.