RTAI
Encyclopedia
RTAI stands for Real-Time
Application Interface. It is a real-time extension for the Linux kernel
- which lets you write applications with strict timing constraints for Linux. Like Linux itself the RTAI software is a community effort.
RTAI supports several architectures:
RTAI provides deterministic response to interrupts, POSIX
compliant and native RTAI real-time tasks.
Realtime Application Interface consists mainly of two parts:
RTAI versions over 3.0 use an Adeos kernel patch, slightly modified in the x86 architecture case, providing additional abstraction and much lessened dependencies on the 'patched' operating system. Adeos is a kernel patch comprising an Interrupt Pipeline where different Operating System Domains register interrupt handlers. This way, RTAI can transparently take over interrupts while leaving the processing of all others to Linux. Use of Adeos also frees RTAI from patent
restrictions caused by RTLinux
project.
Real-time computing
In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...
Application Interface. It is a real-time extension for the Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
- which lets you write applications with strict timing constraints for Linux. Like Linux itself the RTAI software is a community effort.
RTAI supports several architectures:
- x86X86 architectureThe term x86 refers to a family of instruction set architectures based on the Intel 8086 CPU. The 8086 was launched in 1978 as a fully 16-bit extension of Intel's 8-bit based 8080 microprocessor and also introduced segmentation to overcome the 16-bit addressing barrier of such designs...
(with and without FPUFloating point unitA floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
and TSCTime Stamp CounterThe Time Stamp Counter is a 64-bit register present on all x86 processors since the Pentium. It counts the number of ticks since reset. The instruction "RDTSC" returns the TSC in EDX:EAX. In x86_64 mode, RDTSC also clears the higher 32 bits of RAX. Its opcode is 0F 31. Pentium competitors such as...
) - x86-64X86-64x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...
- PowerPCPowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
- ARMARM architectureARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
(StrongARMStrongARMThe StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
; ARM7: clps711x-family, Cirrus Logic EP7xxx, CS89712, PXA25x) - MIPSMIPS architectureMIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
RTAI provides deterministic response to interrupts, POSIX
POSIX
POSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...
compliant and native RTAI real-time tasks.
Realtime Application Interface consists mainly of two parts:
- An Adeos-based patch to the Linux kernel which introduces a hardware abstraction layer
- A broad variety of services which make real-time programmers' lives easier
RTAI versions over 3.0 use an Adeos kernel patch, slightly modified in the x86 architecture case, providing additional abstraction and much lessened dependencies on the 'patched' operating system. Adeos is a kernel patch comprising an Interrupt Pipeline where different Operating System Domains register interrupt handlers. This way, RTAI can transparently take over interrupts while leaving the processing of all others to Linux. Use of Adeos also frees RTAI from patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
restrictions caused by RTLinux
RTLinux
RTLinux or RTCore is a hard realtime RTOS microkernel that runs the entire Linux operating system as a fully preemptive process.It was developed by Victor Yodaiken , Michael Barabanov , Cort Dougan and others at the New Mexico Institute of Mining and Technology and then as a commercial product at...
project.