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Hi,
I could do with some help in understanding how the different kernels know what CPU they are talking to etc. if i have a windows or Linux disk,i can install them on different computers with different CPU types etc. how do they know what they are talking to ? do they have a place in memory where all the different CPU drivers live and it runs through trying them until it work ?!
I could do with an explanation which carries on from where the bios has finished running its POST test and now loads the OS?? this is where things get fuzzy for me
Thank you for your help 
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The problem is that you are asking for a few books worth of explanation...
In nutshell - The Lounge is not for such...
In more details - OS has a hardware specific core and other parts (mostly in C) are compiled to fit the CPU architecture, so when you install the same OS on different platforms, you are actually installing different binaries...
Skipper: We'll fix it.
Alex: Fix it? How you gonna fix this?
Skipper: Grit, spit and a whole lotta duct tape.
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hey,
hey i understand, just looking for some pointers in right direction
so are you saying the OS is read from the disk and compiled there and then to work with that specific architecture? that kinda makes sense
thank you
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No, the OS source is compiled and linked according to its target system. The final binaries will then be written to an installation disk. But that installation disk will not load if you try it on the wrong hardware.
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No! OS does not compile nothing. All is there pre-compiled and installed for the specific platform...
See here: Ubuntu 16.10 (Yakkety Yak) Netboot[^]
Also all packages are pre-installed for different platforms and you have to install the right one from the repository (if you install via the OS, it will set the platform to the same as its own): Ubuntu – Details of package 0install in yakkety[^]
Skipper: We'll fix it.
Alex: Fix it? How you gonna fix this?
Skipper: Grit, spit and a whole lotta duct tape.
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It's still not very clear sorry, do you know anywhere i can read up on this or what exactly i need to search for? thank you
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I can't see what more to say...
If you have access to a GCC compiler, than write a simple 'Hello World' in C/C++ and as GCC to compile it for different platforms...
After that check the result with some hex editor, to see the differences...
When a Linux distro (like Ubuntu) prepared, they compile it 7 times (at least) each time for a different platform. When you are to download an installer, you pick the proper for your platform... It will install the proper (pre-compiled) binaries fitting to your platform, and defines the update channels and the package sources to point to the repositories of that platform...
Skipper: We'll fix it.
Alex: Fix it? How you gonna fix this?
Skipper: Grit, spit and a whole lotta duct tape.
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ahh ok now i understand, the os is precompiled for the given CPU architecture and stored on disk, the PC then writes this to disk with the Master Boot Record. The when the computer is turned on the bios does its tests, runs the POST test and then loads the OS entry point and then it hands control to the kernel, who handles system calls from various applications running on the OS
Is that correct ?
Thank you very much for your time
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Real simple:
The installed operating system matches the hardware upon which it is installed.
The onboard components match the CPU and it's capabilites. You'd have no luck if you could somehow install an intel CPU on an AMD mother board.
When you boot the system, it really doesn't have to ask as it has no choices in its world.
| Ravings en masse^ |
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| "The difference between genius and stupidity is that genius has its limits." - Albert Einstein | | "If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010 |
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Each desktop and laptop computer contains a tiny shard of the Eye of Magaam, which allows the Eytbit sprites that live within the machine to see just long enough into the future to know which versions of the executables will cause serious problems, if implemented.
In recent years, this has resulted in two major problems:
0. microsoft decided to redefine the Eytbit sprites as single-colour squares, with no Pareetibit to govern them, so inappropriate and damaging executables and libraries are sometimes linked, during implementation.
1. The Eye of Magaam is a finite resource, and not enough people properly recycle their PCs and laptops, so it is fast running out -- which is why people say that the PC and laptop era is coming to an end.
HTH
I wanna be a eunuchs developer! Pass me a bread knife!
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One man knows about fish... one man knows about plants.
One man doesn't know about plants... One man doesn't know about fish.
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Well, you just eat your broccoli as well as your fish [edit] or spam [/edit], or no pudding for you!
I wanna be a eunuchs developer! Pass me a bread knife!
modified 22-Mar-17 9:49am.
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I was kind of hoping you were real enough to understand.... now I know your just shell of a man 
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Shortest answer: go to osdev.org and start reading. This was great place that helped me start developing several level-0 applications (not full OS, though).
Short answer: For most of the things, there is no way to know at Runtime. For OS level this notation *-amd64, *-x86, *-arm64 means a little more than "compiled using that option". There are different system registers and other differences described in a ~1000+ pages manuals for each processor. Due to pre-processor you can make a slightly different version for each CPU architecture at compile time.
Honest answer: Take a look at the code of working linux/windows kernel. You will notice that programmers creating operating systems find that part a little fuzzy, too. Just accept it and live with it.
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Ok so in windows the install comes with various HALs, hardware abstraction layer, which is written specifically for a particular CPU, At install the type of CPU is detected by logic and the right HAL installed.
NT 4 used to support 4 CPU s I recall. It's less these days.
Linux probably wotks in a similar way.
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...when you travel. UK flight ban on electronic devices announced - BBC News[^]
OK, it's only inbound and a few countries at the moment, but ... my Nexus 7 is too long, too wide - and I wouldn't want to read a book on anything smaller. And you know as well as I do that security restrictions don't get eased, they get toughened up. 
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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More security theatre.
If you have an important point to make, don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time - a tremendous whack.
--Winston Churchill
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Singapore is laughing, Changi is not on the list of restricted airports so transiting through Doha or Dubai just became dramatically less attractive to a significant sector of the market.
Never underestimate the power of human stupidity
RAH
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That was the intent (well, curtailing gulf carriers to protect US carriers without incurring a WTO case was the intent)
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So if I want to fly - after my vacation in Anatolia - to the UK (to visit OG) I can't take my tablet on the plain, but flying directly from home I can?!
I think that security experts have to decide what is the threat? The men or the machine?
Skipper: We'll fix it.
Alex: Fix it? How you gonna fix this?
Skipper: Grit, spit and a whole lotta duct tape.
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Kornfeld Eliyahu Peter wrote: I think that security experts have to decide what is the threat take out the head from the butt think
FTFY
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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Come on! Don't be hard on them... Making decision is hard enough alone... doing it while thinking?!? 
Skipper: We'll fix it.
Alex: Fix it? How you gonna fix this?
Skipper: Grit, spit and a whole lotta duct tape.
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Back in 2006, when I was commuting between UK & Hungary, there was no hand luggage allowed at all. You were allowed to take through your ticket, passport and money.
In those days I was still smoking and the procedure was after check in, go airside, buy a pack of tabs and to the bar! People would shockingly TALK! There were never matches or lighters left at Smiths, but that was no worry as people who had bought them left them for others to use. oving around the airport was easy, no bags everywhere and even though there were the same number of flights, you could find seating, weird.
From the experience, I can say that the less people can take in the cabin, the better.
veni bibi saltavi
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Nagy Vilmos wrote: here were never matches or lighters left at Smiths,
Indian Airports have solved it elegantly, there is a heating resistance device on the wall of the smoking room.
Nagy Vilmos wrote: From the experience, I can say that the less people can take in the cabin, the better.
It makes it much faster and comfortable. The problem comes when companies have a policy, don't let your laptop out of your sight.
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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Nagy Vilmos wrote: People would shockingly TALK!
:shudders: now that was bad! Have you ever listened to people talking?
* CALL APOGEE, SAY AARDWOLF
* GCS d--- s-/++ a- C++++ U+++ P- L- E-- W++ N++ o+ K- w+++ O? M-- V? PS+ PE- Y+ PGP t++ 5? X R++ tv-- b+ DI+++ D++ G e++>+++ h--- ++>+++ y+++* Weapons extension: ma- k++ F+2 X
* Never pay more than 20 bucks for a computer game.
* I'm a puny punmaker.
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