Subject: Re: where do system calls from userland start
To: Travis H. <firstname.lastname@example.org>
From: Hubert Feyrer <email@example.com>
Date: 08/25/2006 03:22:25
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On Thu, 24 Aug 2006, Travis H. wrote:
> I was going to teach someone about the kernel, and I wanted to start
> them at the system call entry point, but I've forgotten what file that
> is located in. I assume it's in the x86-specific code (for the x86
> platform, anyway); anyone know offhand?
See "Ablauf Systemaufruf - von der libc in den Kernel und zur=FCck" at=20
http://www.feyrer.de/BT/ for an example call of fork(2) on a MIPS system -=
this won't be too different on i386. Sorry this is in German language, but=
I guess you'll get the idea. If not, ask.
> Also, I recall reading about NT internals versus Unix, and someone
> mentioned that if you wanted to add a new system call or change the
> meaning of an argument or add an argument, that you got a lot of
> resistance in Unix. I'm sure there was a good reason, so why exactly
> is that the case? Does NT have a technical advantage in the way it
> handles system calls?
Well what will all the applications do that expect the old behaviour?