Linux is a relatively new operating system that clones the UNIX operating system. It was written by Linus Torvalds and a scattered team of volunteer programmers across the Internet. The Linux kernel and many system components are released under the GNU General Public License (GPL), which dictates that the source code for those components, including modifications, must be made available under the the GPL or a compatible license whenever a compiled version is distributed.
An operating system (OS) is a special program that acts as an intermediary between the computer user and the computer hardware. Apple's MacOS and Microsoft Windows are operating systems. The OS provides an environment to make the computer system convenient and efficient to use. Among other things, the operating system delegates which program should run, manages memory, provides a file system interface, schedules hard disk access, manages the network (e.g. TCP/IP), allows programs to talk to one another, and provides security.
Monday, November 26, 2007
EMBEDDED LINUX
When someone talks about embedding Linux, they mean porting the Linux kernel to run on a particular CPU and board which will be put into an embedded device. There are many companies that sell embedded Linux solutions. These usually include a ported Linux kernel with cross-development tools, and sometimes with real time extensions. For the most part, the APIs and kernel codebase are the same for embedded Linux as desktop Linux.
Why Embedded Linux?
Of course, the "embedded devices" category covers the territory between microwave oven controllers to handheld devices only slightly less powerful than laptop computers. Where does Linux fit into this spectrum? Many are finding that a system as powerful as Linux extends surprisingly low in this range, often being the best choice not only for PDAs but also for appliances and cell phones.
Our goal is not to proselytize Linux, but it is worth mentioning a few bullet points that device manufacturers have found attractive about Linux:
Royalty-free
Strong networking support
Has already been ported to many different CPU architectures
Relatively small for its feature set
Easy to configure
Huge application base
Modern OS (eg. memory management, kernel modules, etc.)
Why Embedded Linux?
Of course, the "embedded devices" category covers the territory between microwave oven controllers to handheld devices only slightly less powerful than laptop computers. Where does Linux fit into this spectrum? Many are finding that a system as powerful as Linux extends surprisingly low in this range, often being the best choice not only for PDAs but also for appliances and cell phones.
Our goal is not to proselytize Linux, but it is worth mentioning a few bullet points that device manufacturers have found attractive about Linux:
Royalty-free
Strong networking support
Has already been ported to many different CPU architectures
Relatively small for its feature set
Easy to configure
Huge application base
Modern OS (eg. memory management, kernel modules, etc.)
RTLINUX
One of the best-known realtime Linux implementations; the development was sponsored by Finite State Machine Labs (FSMLabs), who now sell RTLinux and related products. RTLinux is available under the GPL.
RTLinux claims genuine hard realtime, via an RT kernel which runs the realtime processes, and runs the Linux kernel as its least-priority thread. Processes not requiring realtime response are written as standard Linux apps. Realtime processes are implemented either as realtime threads or interrupt handlers, and are controlled by the RT kernel. The RTLinux project claims a typical 15usec response time to an interrupt assertion on the x86 platform, with an admonishment to compare the worst-case response time (less than 30ms on a 486-33, "near the hardware limit"). Realtime threads follow the POSIX realtime conventions for pthreads. RTLinux is available on x86 (incl. SMP), PPC and Alpha; floating-point support within realtime threads requires the availability of hardware FP, currently working on the x86 and PPC architectures. There appears to be no ARM support.
RTLinux claims genuine hard realtime, via an RT kernel which runs the realtime processes, and runs the Linux kernel as its least-priority thread. Processes not requiring realtime response are written as standard Linux apps. Realtime processes are implemented either as realtime threads or interrupt handlers, and are controlled by the RT kernel. The RTLinux project claims a typical 15usec response time to an interrupt assertion on the x86 platform, with an admonishment to compare the worst-case response time (less than 30ms on a 486-33, "near the hardware limit"). Realtime threads follow the POSIX realtime conventions for pthreads. RTLinux is available on x86 (incl. SMP), PPC and Alpha; floating-point support within realtime threads requires the availability of hardware FP, currently working on the x86 and PPC architectures. There appears to be no ARM support.
what is a RTOS?????
To most people, embedded systems are not recognizable as computers. Instead, they are hidden inside everyday objects that surround us and help us in our lives. Embedded systems typically do not interface with the outside world through familiar personal computer interface devices such as a mouse, keyboard and graphic user interface. Instead, they interface with the outside world through unusual interfaces such as sensors, actuators and specialized communication links. Real-time and embedded systems operate in constrained environments in which computer memory and processing power are limited. They often need to provide their services within strict time deadlines to their users and to the surrounding world. It is these memory, speed and timing constraints that dictate the use of real-time operating systems in embedded software.Basic kernel servicesIn the discussion below, we will focus on the "kernel" – the part of an operating system that provides the most basic services to application software running on a processor. The "kernel" of a real-time operating system ("RTOS") provides an "abstraction layer" that hides from application software the hardware details of the processor (or set of processors) upon which the application software will run.
Figure : Basic Services Provided by a Real-Time Operating System KernelThe most basic category of kernel services, at the very center of Figure , is Task Management. This set of services allows application software developers to design their software as a number of separate "chunks" of software -- each handling a distinct topic, a distinct goal, and perhaps its own real-time deadline. Each separate "chunk" of software is called a "task." Services in this category include the ability to launch tasks and assign priorities to them. The main RTOS service in this category is the scheduling of tasks as the embedded system is in operation. The Task Scheduler controls the execution of application software tasks, and can make them run in a very timely and responsive fashion.
The second category of kernel services, shown at the top of Figure 2, is Intertask Communication and Synchronization. These services make it possible for tasks to pass information from one to another, without danger of that information ever being damaged. They also make it possible for tasks to coordinate, so that they can productively cooperate with one another. Without the help of these RTOS services, tasks might well communicate corrupted information or otherwise interfere with each other.Since many embedded systems have stringent timing requirements, most RTOS kernels also provide some basic Timer services, such as task delays and time-outs. These are shown on the right side of Figure 2.Many (but not all) RTOS kernels provide Dynamic Memory Allocation services. This category of services allows tasks to "borrow" chunks of RAM memory for temporary use in application software. Often these chunks of memory are then passed from task to task, as a means of quickly communicating large amounts of data between tasks. Some very small RTOS kernels that are intended for tightly memory-limited environments, do not offer Dynamic Memory Allocation services.Many (but not all) RTOS kernels also provide a "Device I/O Supervisor" category of services. These services, if available, provide a uniform framework for organizing and accessing the many hardware device drivers that are typical of an embedded system.
Friday, October 12, 2007
Friday, September 28, 2007
Chirutha - Movie review (Keka--kummu)
Ram Charan’s father, is an honest person and auto driver by profession. The kid boy RC loses his parents when his father fights down against a crime. For his survival the boy gets arrested on a murder case which he never does. After his term in jail he finds a job as a guide with a travel agent. As part of his job he’s sent to Hong Kong! There he bumps into the beauty, Prakash Raj’s daughter, who happens to be there as a tourist. He already knows the girl since he comes across her once in India.
That is the story of first half. Songs are foot tapping, which go well with young audience. Ram Charan’s performance is quite mellowed and doesn’t look like a debutante. Especially he performed high in the action scenes. Though he also looked good at dances, he couldn’t be used to the fullest since choreographer’s composition is not up to the expectations.
Puri’s son played the role of Ram Charan as kid. First half is OK with all the necessary entertainment for youth.
With twists and hero’s adventures movie comes to an end. Ram Charan worked with ease in sentiment scenes and there is a sort of punch in dialogue delivery. Choreography should have been taken care of more. It doesn’t appeal like a Puri Jagannath’s movie, in terms of screenplay. Finally, for RC, ‘Chirutha’ turns out to be a good platform to begin with.
Wednesday, September 12, 2007
Tuesday, September 11, 2007
Thursday, September 6, 2007
Chandamama movie review...
Krishnavamsi comes up with another winner. The film is a beautiful story about two young boys and girls. The film, as the titles suggests, is as beautiful as the full moon. Watching the movie is almost like spending a couple of hours out in the open on a full moon night.
There are fights, no vulgar or double meaning dialogues, no villains, and yet, the film keeps you completely engrossed till the end.
Story:
The story is about a young girl Mahalakshmi (Kajal) and her doting father Nagababu. Nagababu is a good at heart rich landlord. She finisher her studies in the city and comes home. She has a cousin sister Rani (Sindhu Menon) who is a naughty girl. Her father fixes up a good alliance for her with Dorababu (Siva Balaji), who is the son of Ahuthi Prasad, a rich landlord. And the wedding preparations are on. The film doesn’t end her, but it actually takes off from here.
Mahalakshmi has a flashback. She was in love with Kishore (Navdeep) but comes home feeling that he has cheated her. Mahalakshmi reveals this to her would-be, Dorababu. She is more worried about her father. She doesn’t want her father to know about this.
The rest of the story runs with twists and turns, with a liberal dose of comedy, action and sentiment. What happens to Mahalakshmi, Dorababu, Kishore and Rani forms the rest of the story.
Performance:
Nagababu comes up with a restrained performance as a loving father. Kajal is equally good as the young daughter who loves her father very much and she is good in the emotional scenes too. Siva Balaji’s role is tailor made for him and he has done a very good job. Navdeep plays the typical city kid with his mannerisms and cool attitude towards life. Sindhu Menon as the chirpy and boisterous cousin of Mahalakshmi is very convincing. Ahuthi Prasad plays a role of a rich landlord who while away al his time playing cards and drinking. But he gets a role that has a lot of scope to perform and he excels. He shows shades of Ravugopala Rao. His role has acutely been moulded along Ravugopala Rao’s style and mannerism. Uttej gets a decent role in the movie and he plays his part to perfection. The rest of the star cast lends good support.
Music by KM Radhakrishan is very good. Al the songs are good and the picturization is also lovely.
The film has no comedy actors but the film is full of comedy. Siva Balaji, Navdeep and Ahuthi Prasad between them give a laughter riot. Particularly Navdeep’s predicament evokes a lot of laughter.
The item song with Abhinayasri has also been filmed very tastefully without any trace of vulgarity. The antakshari game in the second half, where everyone sings a song on Chandamama is a treat to watch. The comedy scene between Ahuthi Prasad and Navdeep, where they both get drunk also evokes a lot of laughter.
Krishnavamsy shows both the rural background and the urban landscape in a very convincing manner. The village backdrop with the lush green fields and innocent villagers takes one back to the good old days.
The only time Krishnavamsy went overboard was in the song – Bugga Meeda Mudhu Pettu, Chempa Paina Muddd Pettu. Both the heroes took it as a license and go about kissing the heroines at all places, which is the only slightly embarrassing scene in the entire movie.
All in all, the film is a pleasurable experience and can be enjoyed with the entire family. The film is so refreshingly good that one may be tempted to watch it a second time too.
There are fights, no vulgar or double meaning dialogues, no villains, and yet, the film keeps you completely engrossed till the end.
Story:
The story is about a young girl Mahalakshmi (Kajal) and her doting father Nagababu. Nagababu is a good at heart rich landlord. She finisher her studies in the city and comes home. She has a cousin sister Rani (Sindhu Menon) who is a naughty girl. Her father fixes up a good alliance for her with Dorababu (Siva Balaji), who is the son of Ahuthi Prasad, a rich landlord. And the wedding preparations are on. The film doesn’t end her, but it actually takes off from here.
Mahalakshmi has a flashback. She was in love with Kishore (Navdeep) but comes home feeling that he has cheated her. Mahalakshmi reveals this to her would-be, Dorababu. She is more worried about her father. She doesn’t want her father to know about this.
The rest of the story runs with twists and turns, with a liberal dose of comedy, action and sentiment. What happens to Mahalakshmi, Dorababu, Kishore and Rani forms the rest of the story.
Performance:
Nagababu comes up with a restrained performance as a loving father. Kajal is equally good as the young daughter who loves her father very much and she is good in the emotional scenes too. Siva Balaji’s role is tailor made for him and he has done a very good job. Navdeep plays the typical city kid with his mannerisms and cool attitude towards life. Sindhu Menon as the chirpy and boisterous cousin of Mahalakshmi is very convincing. Ahuthi Prasad plays a role of a rich landlord who while away al his time playing cards and drinking. But he gets a role that has a lot of scope to perform and he excels. He shows shades of Ravugopala Rao. His role has acutely been moulded along Ravugopala Rao’s style and mannerism. Uttej gets a decent role in the movie and he plays his part to perfection. The rest of the star cast lends good support.
Music by KM Radhakrishan is very good. Al the songs are good and the picturization is also lovely.
The film has no comedy actors but the film is full of comedy. Siva Balaji, Navdeep and Ahuthi Prasad between them give a laughter riot. Particularly Navdeep’s predicament evokes a lot of laughter.
The item song with Abhinayasri has also been filmed very tastefully without any trace of vulgarity. The antakshari game in the second half, where everyone sings a song on Chandamama is a treat to watch. The comedy scene between Ahuthi Prasad and Navdeep, where they both get drunk also evokes a lot of laughter.
Krishnavamsy shows both the rural background and the urban landscape in a very convincing manner. The village backdrop with the lush green fields and innocent villagers takes one back to the good old days.
The only time Krishnavamsy went overboard was in the song – Bugga Meeda Mudhu Pettu, Chempa Paina Muddd Pettu. Both the heroes took it as a license and go about kissing the heroines at all places, which is the only slightly embarrassing scene in the entire movie.
All in all, the film is a pleasurable experience and can be enjoyed with the entire family. The film is so refreshingly good that one may be tempted to watch it a second time too.
Download Lakshmi putrudu songs(Uday Kiran....)
Download Here..
click the link below and enjoy the High quality Mp3 songs of rocking star Uday kiran..
http://www.mediafire.com/?9md2bhs02f9
enjoy well
click the link below and enjoy the High quality Mp3 songs of rocking star Uday kiran..
http://www.mediafire.com/?9md2bhs02f9
enjoy well
Tuesday, September 4, 2007
Sundara Nagaram Visakhapatnam...
Hey..The Most beautiful city in Andhra is Vizag....
Share ur experiences...
Share ur experiences...
Fans of Sada(Telugu heroine)
HI friends..
A glad welcome to all the fans of sada..
Lets have fun here..
Plz share or upload different photos of sada here...
A glad welcome to all the fans of sada..
Lets have fun here..
Plz share or upload different photos of sada here...
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