An operating system (OS) is a basic software whose rule is to intermediate software requisitions for resources and the hardware available, manage input/output, memory allocation/deallocation, file systems, among other basic tasks a device should do.

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Can MCU ROM and RAM limitations be scaled? [migrated]

Please note: Although this specific question has to do with the 32-bit ARM SAM3X8E Cortex M3 series, it is really a generic question that should be applicable to all microcontrollers, and therefore ...
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1answer
30 views

RIOT-OS and multiple executables?

I am brand new to embedded programming and am wondering if RIOT-OS has the capabilities that my small project requires. I have 3 executables, fizz, buzz and foo. They all do separate - but very ...
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3answers
160 views

Why don't operating system start to copy files just after formatting? [closed]

I'm wondering why do OS don't start to copy files just after formatting and wait for us to answer the language questions? Or do they? Thanks!
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1answer
32 views

Move file into apropriate directory based upon first letter of second word, followed by the first two letters of the second word with Python [closed]

EDIT: Apparently the below question is too specific. Let me rephrase: I'm looking for a way to fit a letter into a list of specified ranges such that, if given the letter S and the ranges A-F, G-M, ...
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4answers
173 views

Relation between Kernel & BIOS routines [duplicate]

How does a Kernel provides different functionality to OS? Does it use the BIOS routines or use special device drivers for this, or something else? If uses BIOS how does it come to know which routine ...
22
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5answers
3k views

Why don't Windows/Linux use relational Databases (RDBMS)?

Why don't Windows/Linux use relational databases (RDBMS)? I know they use file systems to store all data but don't you think it is more efficient to use databases like we use in web sites/web apps? ...
2
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0answers
169 views

Cross-compiling Java app to run directly on ARM

Please note: although I am using ARM SAM3X8E in this example, I'm just using that as a concrete example, and the answer to this question could easily be given using any other MCU such as AVR, etc. I ...
2
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2answers
116 views

Compiling and deploying a C program to an MCU running an RTOS

Please note: Even though I'm specifically talking about an RTOS called Embox here, and even though I'm talking about AVR/ARm, I think this question can be answered by anybody whose ever done a fair ...
2
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1answer
69 views

Compiling and deploying RTOS to an MCU

Please note: Even though I'm specifically talking about an RTOS called Embox here, and even though I'm talking about AVR/ARm, I think this question can be answered by anybody whose ever done a fair ...
3
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2answers
269 views

Benefits of RTOS vs Bare Metal for MCU Programming?

Please note: This question specifically mentions two RTOSes but is more generic and can probably be answered by anybody who has written C code for embedded RTOSes before, and had their software run ...
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2answers
107 views

Is renaming an 'alias' for moving?

Is it true to say (on Windows and Unix\Linux\OS X) that renaming a file or directory is just an alias for moving? e.g. Are there any side effects to either which are not present on the other? Does ...
4
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52 views

Seeking opinions on using device tree for I/O definition

I've been working ELLCC, a clang/LLVM based development tool chain targeting ARM, Mips, Microblaze, PowerPC, and x86 targets. The tool chain is pretty complete and runs on Linux, Windows, and Mac OS ...
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1answer
83 views

What are the components of a process? [closed]

What exactly is a process and what all things is a process comprised of? I have read the Wikipedia page and I found only abstract details over there. I want to know what details are stored by a ...
0
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3answers
115 views

What is the explication for the difference execution time for the same instruction?

As you know when we run instruction in our code like long a = b; we will not have the same ticks each to be executed. first exeution it take 2ticks; second exeution it take 3ticks; third exeution it ...
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2answers
47 views

Examples of operating systems capable of serving http-requests that does not support direct slash for directory separator

My php framework uses DIRECORY_SEPARATOR constant instead of /. Can there be any other options for a directory separator?
1
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1answer
71 views

Translation Lookaside buffer - Lookup By Page Size

I am having a hard time finding documentation that explains precisely how the various TLB caches are used in modern processors. Most modern processors have separate TLBs for code/data. That in itself ...
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5answers
589 views

Do bare computer systems (without OS installed) use (executable) files?

As far as I read, files are introduced in OS books. Before an OS is installed on a bare computer system, does the computer use files? In particular, executable files have formats in OSes, e.g. ...
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3answers
299 views

Programming in Linux (C++) [closed]

So I don't know If this is the right place to ask this. I am new to programming, I am not very in to it (I know classes,arrays,functions..etc(Basic Things)). I was programming with Visual Studio 2013 ...
14
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3answers
853 views

Why aren't “fat binaries” more widely used for cross-platform applications?

As far as I know, so-called "fat binaries"--executable files that contain machine code for multiple systems--are only really used on Apple PCs, and even there it seems like they only used them because ...
3
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2answers
853 views

How do you usually compile C/C++ source code ? (Large code bases) [closed]

It's been quite some times since I began learning C and C++ but I've been very limited only to the Windows platform and the Visual Studio environment. Recently, I wanted to look into some open source ...
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1answer
74 views

What are the languages, objects, data types, operations and features for lower levels in a multilevel model of a computer system?

From Structural Computer Organization by Tanenbuam In a certain sense, a computer with n levels can be regarded as n different virtual machines, each one with a different machine language. We ...
2
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2answers
2k views

How does a DMA controller work?

From Section 5.1.4 Direct Memory Access in Modern Operating Systems by Andrew S. Tanenbaum, Herbert Bos, 2014, To simplify the explanation, we assume that the CPU accesses all devices and memory ...
3
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2answers
192 views

are multithreading, multiprocessing, multitasking implemented at instruction set or OS?

On a computer with a single cpu core, must a multithreading program be implemented based on an OS? Can it be implemented in the instruction set and run without an OS? Can multiple programs run in ...
27
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3answers
2k views

Kernel mode web servers: A clever optimization or a security nightmare?

I was reading a Hacker News thread where one user posts a link from 2011 explaining that IIS is much faster than most other (*nix) web servers. Another user replies, explaining that IIS gets that ...
3
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4answers
352 views

Does it make sense to say if an OS is Turing complete

The book "Modern Operating systems", says The Operating System is an Extended Machine. So I wonder if an OS is a model of computaion, and whether it makes sense to say if an OS is Turing ...
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1answer
91 views

What differences are between “play-by-play”, design and implementation of an OS? [closed]

From two books' review Daniel Bovet and Marco Cesati. Understanding the Linux Kernel (2nd Edition or newer): Note: this book has some tendency to function as a play-by-play of what happens ...
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4answers
171 views

Why is there little use of filesharing as compression (outside of libraries)?

Recently I was looking for a program that will run as a daemon and find files that have the same size/type, check if they're the same, then make both a hard link to a single copy if they are. And I ...
1
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0answers
85 views

Concurrent Processes - Monitors and Reader/Writers

So this is a general question about the use of monitors in the Reader/Writers problem. I know the monitor procedures for the Readers/Writers problem are used for mutual exclusion to a critical ...
0
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1answer
169 views

What metadata do files contain? [closed]

I know when a file is created date information such as date created, last modified, last opened, is automatically updated as meta data on that file. Is there other meta data though? Specifically, is ...
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4answers
1k views

Why was Fortran never used to develop an Operating System?

I'm not a Fortran developer myself, but I'm about to use it a little and found myself wondering why, if it is much older than C but equally as performant as C, was it never used to develop any ...
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0answers
43 views

Semaphore : one for each shared resource?

Normally semaphores are implemented as integer variables. The value of a semaphore represents initially the number of processes that are allowed to access the shared resource at the same time, which ...
-2
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1answer
324 views

What are steps in making an operating system in C ? [duplicate]

I am trying to make an my own OS. This is for educational purpose only, so that I get to understand the internals as well as get a good idea of low level programming. I have some prior application ...
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1answer
98 views

How do processes communicate? [closed]

What transports/pipes/interops are available that most or all languages support across OSs? Not necessarily, network, but interprocess. Or is interprocess communication OS specific? I mean, for ...
3
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3answers
2k views

How to operate a computer without an operating system?

How a computer can be used when there is no operating system? What tools or knowledge do I need to do it? Do I have to give all the commands in binary to use computer hardware resources like a ...
62
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11answers
8k views

Why is software OS specific?

I'm trying to determine the technical details of why software produced using programming languages for certain operating systems only work with them. It is my understanding that binaries are specific ...
0
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3answers
133 views

What are the limits of using OS X when it comes to compiling and running CLI-based tools and scripts that were written with Linux in mind?

I run little scientific scripts and C tools on OS X from time to time. For the C tools, I just download the source and compile using the provided Makefile. I usually don't have any problems when using ...
5
votes
1answer
383 views

How do programming languages integrate with OS runtimes

For example, Objective-C, Swift and Ruby (i.e. RubyMotion) integrate with the Cocoa framework. Is this done via linked libraries? I assume they call functions in existing binaries instead of simply ...
3
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1answer
164 views

Why do we need fork to create new process

In Unix whenever we want to create a new process, we fork the current process i.e. we create a new child process which is exactly the same as the parent process and then we do exec system call to ...
1
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6answers
536 views

Why can we not insert into files without the additional writes? (I neither mean append, nor over-write)

This occurs as a programming language independent problem to me. I have a file with the content aaabddd When I want to insert C behind b then my code needs to rewrite ddd to get aaabCddd Why ...
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2answers
300 views

Multi-level paging tables

Referring to the image here: From http://en.wikipedia.org/wiki/File:X86_Paging_4K.svg Could somebody please explain something for me? I don't get exactly how this works. As I understand it the ...
0
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1answer
226 views

Scheduling between child and parent process

When child processes are created using the fork system call what is there scheduling priorities..are they same? if so will always a child process run first and then parent...or is there a manipulation ...
3
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5answers
646 views

Virtual machine for a high level programming language vs an operating system

It struck me recently that a virtual machine for a high level programming language is very much like an OS. It manages resources, e.g. stack, heap, etc. similar to how an operating system manages ...
-1
votes
1answer
158 views

How do memory-clean apps work? [closed]

In terms of operating system architecture, what does a memory-clean software to get rid of all data that fill the virtual memory? I assume that it simply saves all RAM data into a file, but how does ...
1
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1answer
125 views

How do programs generally get information from the OS?

In many languages there are libraries, either built into the language itself or built separately outside of the language, which allow information to be taken from the operating system at some level. ...
4
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2answers
111 views

How should an embedded OS be combined with user code?

As a side-effect of an embedded project I've been working on, I've developed a small operating system for an ARM processor. While the OS and my user code are in separate directories and have clean ...
0
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2answers
421 views

Little and Big endian confusion

Just to make sure if I understand this correctly. Is this right that little endian processors read the memory addresses from highest to the lowest address and where as a big endian processors suppose ...
0
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3answers
214 views

If mutual exclusion is not implemented, how would we detect a race condition?

Suppose we are in a distributed environment, and mutual exclusion is not implemented yet. So how would we be able to detect race conditions? When I researched, use of non-blocking algorithms was ...
0
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0answers
115 views

Why user threads are mapped to Kernel threads

Since user threads are mapped to kernel threads, why don't we create all threads as kernel threads that is a process with zero user thread. Doesn't mapping of user thread to kernel thread create ...
-1
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1answer
224 views

Linux kernel development

I am trying to understand the linux kernel and there is one thing that is puzzling me for quite a while. As linux is used across variety of platforms (like smartphones,desktop,supercomputers etc) and ...
3
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2answers
4k views

How Stack and Heap is allocated for threads under the same process in Windows?

Stack for different thread is different.but what about Heap. If Heap is different for different threads, then how they share objects?