Hello,
I just wanted to make a question What knowledge would it take to make A operating system if you could tell me Cause I am starting to get into building program it may take A long time but dont worry one day your data will be safer then ever I am hoping to do a couple of things in here against bug/virus Encryption and hard ways to get past stuff... If someone would be willing to help me out...
Danka sir!
For the original C (and similar for Unix) they did bootstrapping, for example they built a small version (some features) of the C compiler using assembly, then they wrote a better C compiler (not all features of C) using the C compiler they had made with assembly ("the chicken and egg" problem :o), then they wrote an even better C compiler and compiled with the C compiler they had gotten from the previous step etc. After several iterations they had a full C compiler
Since now we have C compilers and OS to use, you can use Windows for the production OS and some Intel compiler or any compiler and assembler for the target CPU you use and compile on Windows. The Windows CE / Pocket PC tools work like that
To find linux sourcecode search for "Fedora core" on the network (I think it's available by Red Hat, it's the core of Red Hat Linux). Else for classic Unix (not linux) see BSD (Berkeley Software Distribution) Linux that MacOS-X uses at its core
However it's too advanced topic to get searious with, just poke arround to get some idea of the size of such a project (the drivers parts is the harder one maybe, plus you have to use algorithms for optimizing disk access etc. and some are patented and you either license them or invent your own - Similar goes for file formats and file systems like NTFS [MS recently patented it I think])
I don't think I'm oversimplifying the problem any when I say that you'll need to know just about everything. I'd suggest you start by reading as much as you can on topics like x86 assembly language and PC architecture. Keep in mind that any resources you find specifically related to designing/writing operating systems (I'm sure there are a few) are going to be aimed at highly sophisticated programmers, not beginners. Also try to keep in mind that the OSs that are widely available now (Windows, Linux, and whatever Macs use) required teams of thousands working steadily for years to get them into their current state.
OS is an abbreviation for Operating System. Hence MS-DOS (Microsoft Disk Operating System) and similar...
Just curious, no big deal but why did you write A operating system? Ah, forgive me, you probably speak English as a Second Language. I'm a HS English teacher so I get nosy about odd errors in grammar and syntax.
To write an operating system, and then to compile it, debug it, compile it, debug it, until its ready to eat, if you will, requires:
1. Use a "low-level" programming language: as close to hardware instructions as you can get; Assembler, for example. (Unless things have changed in CPU technology SO MUCH that there is no longer an instruction set as I used to know it--never take any one, single persons word--especially whom you do not know much about. Ask around.
Butt Assembly Language or "C++" (I learned on Kernigan and Ritchie's "C", I presume C++ is also relatively low level, but it is a true programming language. Issuing code to execute a program, a million years ago, would look like:
mov AH,0
int 21,H
Here's another byte to chew on:
All of the following are the same hex number in Assembler, 10h, 10H, &H10, &h10
The info to take home is simply that all hex numbers end with an H (or h), or &H (or &h). H/h is a suffix. &H,&h is a prefix.
Same difference.
You know of course that PCs have different model, manufacturer, and BIOS, so perhaps you ought to just let a high-level language do the work for you, and translate (parse) your code into a specific CPU-readable operating system. I believe you should always start at first principles. Do you know that transistors have P/N junctions and depending on the amount of electricity sent through them, since they are neither dielelctric (say, rubber) or conductors (e.g., copper) but semiconductors (Sililcon dioxide or "doped" boron or phosphous? potassium?). Semiconductors' characteristics change depending on how much juice they get. Thus they're rock bottom switches, and do all the arithmetic and logic. All this might mean nothing to you if programs like Visual Basic .NET can write an O.S., which it probably can. Good luck. Where're you from (before here?).
dg
