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Questions tagged [operating-system]

Questions related to software that manages computer hardware resources, and more specifically microcontroller or microprocessor operating Systems

17
votes
4answers
3k views

What stops an assembly program from crashing the operating system? [closed]

First of all, I am a beginner, so if this question sounds silly, please point out the incorrect assumptions. From what I understand, the job of an operating system is to manage hardware and the ...
1
vote
3answers
1k views

What is the role of ISA (Instruction Set Architecture) in the comp arch abstraction stack. [closed]

I have programming background, and I recently started taking computer architecture course. Most of the lectures I see use the some sort of the layering as described in the following diagram explaining ...
0
votes
4answers
137 views

Linux on board without 3rd party modules. Where to start? [closed]

I would like to be able to design my own Linux board the way I design my own micro-controller boards. The complexity is obviously going to be higher from PCB design and assembly point of view, but I ...
-1
votes
1answer
275 views

Is it Possible to Design an Entire Operating System or App using ASIC Chips? [closed]

ASIC chips are hundreds of times faster than traditional chips. Is it possible to design an entire operating system or application using a full custom ASIC chip? Based on what I've read I understand ...
0
votes
0answers
50 views

How do distribution/transmission operators manage unbalances from LV grids?

Low voltage (LV) grids are characterized for being unbalanced due to: 1) the considerable amount of single loads, 2) unbalanced three-phase loads, and 3) unequal impedances in the cables/lines that ...
-2
votes
12answers
2k views

How exactly does the transition between Software and Hardware occur?

Well first allow me to explain what I actually meant to ask. Ok, so it is clearly known that without software, a piece of hardware is just a lifeless body, something without a soul. But I clearly ...
-2
votes
2answers
176 views

What makes a circuit bootable or capable of runnning an OS? [closed]

I posted this on StackOverflow for the premise that any programmer (not an HTML coder, who does not, strictly speaking, do programming, though HTML does require a lot of specific knowledge and bears a ...
1
vote
1answer
180 views

When would it become necessary to use an OS for an ARM MCU [duplicate]

I take it an ARM MCU can be run without an OS - at which point might it become necessary to install one? Can the mbed SDK run without the mbed-os or any other mbed for that matter?
0
votes
0answers
114 views

When should one use a RTOS (real-time OS) over a simple infinite while loop in an embedded system? [duplicate]

The Arduino uses a simple infinite while loop. It works fine for me so far. What are some situations when a more complex RTOS is needed?
3
votes
4answers
820 views

Real time operating systems

I have been asked this question: “Do you think the system will need deterministic time or real time responses?” The problem I have is distinguishing the difference between the two. I know that a real ...
0
votes
1answer
132 views

Operating system on an ARM9 MCU

I have an ARM926EJ MCU (datasheet) that I am learning how to program for a research project. I have been researching, as well as reading a textbook on Professional Embedded ARM Development in order ...
0
votes
2answers
227 views

Where can I learn? [closed]

Ok, so first I want to say that I'm only in a mere 9th grade but done let my years dictate my experience and expertise to you. So I'm looking at open courseware but I'm not sure what course to look ...
0
votes
2answers
427 views

Why can't we have counting mutexes?

I understand the difference between a semaphore and a mutex (I think). Only the task that acquired the mutex can release it. What if we had three identical ports that are shared amongst tasks and ...
0
votes
1answer
63 views

Need verification of real-time concepts

I want to check whether I understand correctly: Real-time means an action always performs in a specified amount of time and is never late for deadline - an upper bound, and sometimes a lower bound as ...
0
votes
2answers
1k views

Microchip PIC - How to recover the context saved in interrups or disable the automatic saving of the context?

I'm building a dispatcher for PIC microcontrollers to switch tasks saving their contexts. The dispatcher is triggered when an interrupt occurs. The problem is that the compiler I'm using (C18 V3.x) ...
1
vote
4answers
2k views

Function Pointer in C Language

I'm facing a little problem with function pointers in a code for the microcontroller Microchip Pic 18 Series. The code below shows the prototypes of the functions involved in the problem and a call ...
1
vote
2answers
885 views

Homebrew Computers - TTL/FPA computer that can run a POSIX OS? [closed]

The internet is filled with inspiring examples of homebrew computers, including ones made from relays and TTL gates. In the first year of Make Magazine - they describe a person who builds a simple ...
2
votes
3answers
532 views

History, reason for and implications of the 2 modes of a modern microprocessor?

The modern microprocessors I've dealt with could have 2 modes: User and superuser (and sometimes this difference was just in the manual and not actually implemented like with the Nios II which states ...
0
votes
2answers
1k views

What happens on a Cache miss?

In the present day processors more than one level of memory is present for trying for the realization of an ideal memory system and to do more work for clock cycle more than one instruction is in the ...
22
votes
5answers
9k views

When do we need an Operating System in Embedded System Design?

I have written plenty of bare metal code for PIC and x86 processors. Can someone tell me how and when should I need an operating system? Conversely, what application or situation can be dealt with ...
3
votes
2answers
243 views

Task switching on Cortext-M3 crashes after IRQ

I've used an exokernel model for my ARM OS. When a task wants to read from a UART it calls a library function, which, if there's no data, makes a SVC call to block the task (which causes the kernel to ...
0
votes
2answers
384 views

Do I need an OS in my device?

I am planning to build a device that will help transfer data from one USB storage device to another.I am planning to incorporate a touch screen interface to provide the user with more control over ...
14
votes
3answers
6k views

What are the benefits of a non-preemptive OS? and the price for these benefits?

For a bared metal MCU, Comparing to the homemade code with background loop plus timer interrupt architecture, what are the benefits of a non-preemptive OS? What among these benefits are attractive ...
0
votes
1answer
159 views

Calling ports in C on my microcontroller

I have been developing a small OS for my lpc1313fbd48. I am sending all of the C and assembly code in a binary file. I want to be able to call the ports in C and have an LED turn on for a few seconds ...
16
votes
1answer
528 views

What features distinguishes real-time from other types of os?

I'm experimenting with a small so-called real-time kernel that basically can do nothing but counting to the next prime. It uses interrupt-driven I/O. But why is it a real-time kernel? I read that ...
7
votes
3answers
203 views

How do I find energy leaks?

I'm in a process of writing software for eZ 430 Chronos watch using TinyOS. I want it to be as low-power as it is possible. Unfortunately, my measurements show power consumption of about 350uA @3.3V ...