Re: Query regarding Copy-on-write

[Simon Valiquette <v.simon@ieee.org>]

Jagadeesh Bhaskar P a écrit :
> 
>>and also made a minimalist OS for a MC68000 microcontroler 
>>(only basic process support without even support for a filesystem). 
> 
> 
> 
> I too want to learn something like a minimalist OS. Where to start
> digging?
> 

   I'm not too sure.  In my case, I started mixing assembly language and 
Pascal about 15 years ago while quite young.  It really helps :o)



   I know there is things likes Nachos, OSP or Minix (yes, that's the 
one used by Linus) for learning how to write operating systems.  I 
personnally prefer a real OS like Hurd, but if you have a teacher or 
someone to assist you, I guess they can be usefull.


   To write a real OS, you need to understant how your hardware is 
working and to have the documentation book to know how to program it and 
manage it's interruptions.  Beeing efficient in assembly language is a 
must, even if you do most of your coding in C language, as it helps you 
to understand your computer.

   A book that might help you saving time, and that I found both very 
informative and interesting is this one:

   "Operating systems" from William Stallings, Prentice Hall.

   It won't tell you how to code everythings, but it will explain the 
algorithmes and ideas of differents Operating systems for doing similar 
tasks.  For example, it compares Posix threads with Linux, Windows and 
Solaris threads.  I found it quite complete; it even talk about RAID-6, 
and my book is many years old.


   Understanding as many OS as possible will certainly helps you 
understanding differents concepts and improve your skills.  OS likes 
Inferno, QNX and Plan 9 are probably good for that.


   For going back to your question, once you feel ready, you should 
probably start by trying to write a small OS.  At first, all you will 
need to write is a sheduler, a way to start programs and a way to kill 
them.  Writing something similar to /sbin/init with a couple of built-in 
commands (for starting, showing and stoping processes) will also 
simplify things.


   Eventually, you could add (or emulate) a file system.  By the way, 
the sheduler should be activated by interruptions, otherwise you will 
just have an improved version of DOS 1.0  ;o)


Simon Valiquette

---
win-nt from the people who invented edlin
(By mwikholm@at8.abo.fi, MaDsen Wikholm)

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs