Subject: Re: HEADS UP: migration to fully dynamic linked "base" system
To: Johnny Billquist <email@example.com>
From: Jason R Thorpe <firstname.lastname@example.org>
Date: 08/26/2002 18:07:07
On Tue, Aug 27, 2002 at 02:53:51AM +0200, Johnny Billquist wrote:
> I won't go into the question wether it's a good or bad design. It has it's
> merits, but it's still a hack.
By your labeling it a "hack", you are discounting it as something that
wasn't designed with some thought put into it.
Networking wasn't part of the original Unix design. Nor was the notion
of having multiple kinds of file systems. Because they appear in Unix
now, are they a "hack"?
I'll admit that the way SunOS (and our own a.out) did shared libraries was
a hack; all the magic for starting the dynamic linker was done in crt0, and
was prone to error. But when ELF came along, they defined an interface where
the kernel provided assistance to the dynamic linker (the kernel maps the
dynamic linker, and then provides additional info to it in the form of Aux
vectors), which lives in userland.
You might say it was specifically designed to put the complicated part into
userland, rather than forcing it to live in the kernel. This keeps the
kernel's exec code relatively simple.
-- Jason R. Thorpe <email@example.com>