National Institute of Science & Technology

8/14/2019 National Institute of Science & Technology

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RTLlNUX

ADITYA KUMAR PATTNAYAK ROLLNO: CS200117263

TECHNICAL SEMINARUNDER GUIDENCE OF

MR. P.K JENA

NATIONAL INSTITUTE OF SCIENCE AND TECHNOLOGY,

PALUR HILLS, BERHAMPUR.

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Aditya kumar pattnayak


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WHAT IS REAL TIME SYSTEM.

WHAT IS HARD REAL TIME.

WHAT IS SOFT REAL TIME.

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WHAT IS RTLINUX

RTLinux is a hard real-time operating system thatruns Linux as its lowest priority execution thread .

RTLinux, originally developed at the New MexicoInstitute of Technology .

It is an open-source product.

RTLinux-specific components are released underthe GPL .

Non-GPL versions of the RTL components areavailable from FSMLabs.

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WHY RTLINUX

Linux kernel is completely preemptible.

The kernel has the ability to suspend any user-

level task.

Linux kernel modified to support hard realtime .

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BARE LINUX KERNEL

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U s e r P r o c e s s e s

U n i x / L i n u x K e r

H a r d w a r e

D e v i c e D r i v e r s

S y s t e m L i a b r a r i e s

H a r d w a r e I n t e r rI / O


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RTLinux KERNEL

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U s e r P r o c e s s e s

U n i x / L i n u x K e

H a r d w a r e

D e v i c e D r i v e r s

S y s t e m L i a b r a r i e s

S o f t w a r e I n t e r r uI / O

R T L i n u x P l u g i nR T - S c h e d u l e r

a b c

R e a l t i m e t a s k

I / OH a r d w a r e I n t e r r

D i r e c t h a r d w a r e

A c c e s s


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VERSIONS

There are 3 versions for RTLinux

1. RTLinux V1

2. RTLinux V2

3. RTLinux V3

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THE BASIC API

1. RTLinux programs modeled as modules whichare loaded into the Linux kernel space.

2. main() function is replaced by a pair of

init/cleanup functions:int init_module( );

void cleanup_module( );

3. A filename.c file is converted to a module bycompiling the file.

4. Then use insmod or rmmod command to insert

or remove the module into kernel.

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STRUCTURE OF MODULES

CREATING POSIX THREADSFUNCTIONS

pthread_create(3) :- To create a new thread.

pthread_attr_getcpu_np(3):- getting general attributes

pthread_attr_setcpu_np(3):- setting general attribures

pthread_cancel (pthread thread):- cancelling a thread

int clock_gettime(clockid_t clock_id, struct

timespec *ts):-Get the current clock timinghrtime_t clock_gethrtime(clockid_t clock):-

It returns time in 64 bit number in nanoseconds.

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SCHEDULING THREADS

pthread_attr_setschedparam(3)

pthread_setschedparam(3)

sched_get_priority_min(3)

pthread_make_periodic_np(3)

pthread_wait_np(3)

pthread_make_periodic_np(3)

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INTER PROCESS COMMUNICATION

1. REALTIME FIFO

2. USING SHARED MEMORY

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INTERRUPTS

1. HARD INTERRUPTS

2. SOFT INTERRUPTS

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DIFFERENT PROJECTS UNDER

DEVELOPEMENT Space Robotics: an Experimental Set-up based onRTAI-Linux

Flash Storage in Linux-Based ResidentialGateways,

Real-time Linux in Chemical Process Control

A Digital PID Controller Using RTAI

Graphic Supervisor of Lung Ventilator Driver Architecture in a Linux World

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CONCLUSION

Realtime tasks in RTLlNUX can communicatewith Linux processes via shared memory or a file-likeinterface. Thus, real-time applications can make useof all the powerful, non-real-time services of Linux,

including: Networking ,Graphics, Windowing systems,Data analysis packages ,Linux device drivers, andStandard POSIX API.

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THANK YOU

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