Subject: Re: ARM Linux
To: Peter Berg <Peter.Berg@ww.tu-freiberg.de>
From: Amit Gupta <93akg@eng.cam.ac.uk>
List: port-arm32
Date: 11/12/1996 09:20:14
On Mon, 11 Nov 1996, Peter Berg wrote:

> > Looking around Acorn World I noticed that Russ King now has ARM Linux up
> > and running on a Risc PC. He has implemented StrongARM support and is
> > planning to support the ARM6 and ARM7 also. He has compiled X11R6 with 1,
> > 4 and 8bpp X servers. 
> > 
> > He has shared libraries but only in a.out format, i.e. no
> > position-independent code and no ELF. 
> 
> Can someone explain me why this isn't possible under RiscBSD ? 

My guess would be that it *is* possible but isn't the ideal way of doing
things. As I understand it, a.out involves compiling libraries at a
specific address whereas ELF involves true dynamic linking. 

> > Another possibility might be a single format for executables, compiled
> > with a common version of gcc. This would have obvious advantages when
> > compiling and maintaining ports. 
> 
> I guess this would cause some drastic changes to the gcc code and will not be 
> easy to realize. I'm not shure why they in Linux have invented the ELF format, 
> but I think they had problems with the a.out. But now nearly everything in 
> Linux is ELF now and I know no BSD system which can handle ELF binaries.

I'm not sure that ELF is a Linux-only thing; I seem to recall IRIX and
others using it too. I think it's a System V thing. 

I believe that FreeBSD (on Intel) can handle ELF binaries through its
run_elf tool. 

> I think Linux for the RiscPC comes one and a half year to late and noone will 
> drop his RiscBSD away for a system with less software available.

I don't know - in terms of software, just about anything that compiles
under BSD will compile under Linux. In terms of speed, they're probably
similar. I would guess that some folk would prefer Linux to BSD, simply
because they know it. The issue is really whether two teams should be
duplicating each others work - I don't know too much about kernel/X
programming but it would be a real shame if this happened. 

Remember that Russell is working largely on his own, and has achieved a
staggering amount IMHO. 

amit

P.S. my favourite quote from Acorn World 96 :

[Me] "So, Russell, how long did it take you to get X11R6 running on ARM 
Linux ?"

[Russ] "About a week - but most of that was compile time." 

:-)