Endianness...

Endianness...

[Matthew Dharm]

What's the preferred endianness for Linux-MIPS?  I can't really go
into why I'm asking (sensitive NDA information), but I'm basically
faced with a group that wants to work in LE.  However, my
understanding was that Linux-MIPS generally ran BE.

Or can it be built either way?  I know OpenBSD runs LE.... not like
that means anything to this group, tho.

Matt Dharm

--
Matthew D. Dharm                            Senior Software Designer
Momentum Computer Inc.                      1815 Aston Ave.  Suite 107
(760) 431-8663 X-115                        Carlsbad, CA 92008-7310
Momentum Works For You                      www.momenco.com

Re: Endianness...

[nick]

To the best of my knowledge Big endian is generally the way to run.
	Nick

On Wed, 2 May 2001, Matthew Dharm wrote:

> What's the preferred endianness for Linux-MIPS?  I can't really go
> into why I'm asking (sensitive NDA information), but I'm basically
> faced with a group that wants to work in LE.  However, my
> understanding was that Linux-MIPS generally ran BE.
> 
> Or can it be built either way?  I know OpenBSD runs LE.... not like
> that means anything to this group, tho.
> 
> Matt Dharm
> 
> --
> Matthew D. Dharm                            Senior Software Designer
> Momentum Computer Inc.                      1815 Aston Ave.  Suite 107
> (760) 431-8663 X-115                        Carlsbad, CA 92008-7310
> Momentum Works For You                      www.momenco.com
> 

Re: Endianness...

[Jun Sun]

nick@snowman.net wrote:
> 
> To the best of my knowledge Big endian is generally the way to run.
>         Nick
> 

BE is better known perhaps because all SGI workstations are BE.  Generally I
found networking systems tend to use BE while consumer electronic devices tend
to use LE (which means there are probably more MIPS CPUs running in LE.)

So far I have not found much difference in terms of endianess, although
occassionaly you have to IO swap in drivers for BE machine.

Jun

> On Wed, 2 May 2001, Matthew Dharm wrote:
> 
> > What's the preferred endianness for Linux-MIPS?  I can't really go
> > into why I'm asking (sensitive NDA information), but I'm basically
> > faced with a group that wants to work in LE.  However, my
> > understanding was that Linux-MIPS generally ran BE.
> >
> > Or can it be built either way?  I know OpenBSD runs LE.... not like
> > that means anything to this group, tho.
> >
> > Matt Dharm
> >
> > --
> > Matthew D. Dharm                            Senior Software Designer
> > Momentum Computer Inc.                      1815 Aston Ave.  Suite 107
> > (760) 431-8663 X-115                        Carlsbad, CA 92008-7310
> > Momentum Works For You                      www.momenco.com
> >

Re: Endianness...

[Ralf Baechle]

On Wed, May 02, 2001 at 01:47:07PM -0700, Jun Sun wrote:

> BE is better known perhaps because all SGI workstations are BE.  Generally I
> found networking systems tend to use BE while consumer electronic devices tend
> to use LE (which means there are probably more MIPS CPUs running in LE.)
> 
> So far I have not found much difference in terms of endianess, although
> occassionaly you have to IO swap in drivers for BE machine.

The difference is mostly of religious nature even though I've been told
that various embedded apps can show noticable performance difference due
to byteswapping.  In general I prefer big endian because it tends to
trigger certain bugs in software more than little endian, such as accessing
a memory object with different sizes.

  Ralf

Re: Endianness...

[Kevin D. Kissell]

I have one machine set up each way, an Algorithmics
P5064/R5260 running LE on a 2.2.12 kernel and a
MIPS Malta/4KC running BE under 2.4.1.  There are pros
and cons.  On one hand, most of the "bleeding edge"
work is only tested on BE SGI platforms before being
checked-in, and the BE userland binary distributions
are more complete.  On the other hand, it's generally
easier to port drivers for x86-oriented peripherals to
a LE kernel.

            Regards,

            Kevin K.

----- Original Message ----- 
From: "Matthew Dharm" <mdharm@momenco.com>
To: "Linux-MIPS" <linux-mips@oss.sgi.com>
Sent: Wednesday, May 02, 2001 10:01 PM
Subject: Endianness...


> What's the preferred endianness for Linux-MIPS?  I can't really go
> into why I'm asking (sensitive NDA information), but I'm basically
> faced with a group that wants to work in LE.  However, my
> understanding was that Linux-MIPS generally ran BE.
> 
> Or can it be built either way?  I know OpenBSD runs LE.... not like
> that means anything to this group, tho.
> 
> Matt Dharm
> 
> --
> Matthew D. Dharm                            Senior Software Designer
> Momentum Computer Inc.                      1815 Aston Ave.  Suite 107
> (760) 431-8663 X-115                        Carlsbad, CA 92008-7310
> Momentum Works For You                      www.momenco.com
> 

Re: Endianness...

[Pete Popov]

Matthew Dharm wrote:
> 
> What's the preferred endianness for Linux-MIPS?  I can't really go
> into why I'm asking (sensitive NDA information), but I'm basically
> faced with a group that wants to work in LE.  However, my
> understanding was that Linux-MIPS generally ran BE.
> 
> Or can it be built either way?  I know OpenBSD runs LE.... not like
> that means anything to this group, tho.

I saw some of the replies.  I don't think it's true that BE is "the" way
to go. mips-linux runs both, le and be. We have three different LE
boards and our partners have shipped our LE port to many of their
customers. The Alchemy board I'm working on runs both, LE and BE and
I've tested both.   Depending on the peripherals you want to support,
like USB, PCMCIA, etc, little endian might be a lot easier to port to.
If on the other hand you're interested in a mips64 smp port, then BE is
probably the easiest way to go because of the current support of
mips64.  As far as binary completeness, the RedHat 7.0 port is, I think,
BE. But our HardHat Linux 2.0 will offer the same completeness for both,
LE and BE (should be on the ftp site by the end of the month).

Pete

Re: Endianness...

[Houten K.H.C. van (Karel)]

Pete Popov wrote:

> As far as binary completeness, the RedHat 7.0 port is, I think,
> BE. But our HardHat Linux 2.0 will offer the same completeness for both,
> LE and BE (should be on the ftp site by the end of the month).

My RedHat 7.0 port for LE is also nearly ready. I'm still fighting
with KDE, but I hope to upload a working root FS and rpms soon.

Regards,
Karel.


-- 
Karel van Houten

----------------------------------------------------------
The box said "Requires Windows 95 or better."
I can't understand why it won't work on my Linux computer. 
----------------------------------------------------------

endianness

[Didier Kryn]

	Dear friends, I really had a great fun with the exchanges
about endianness. It changes from the other serious messages :-)

	For sure neither big nor little endiannesses was ever
decided by Nature, but the dispute has to do with human nature.

	The reason of attachment of most of us to one of these is
just habit. I have allways used big-endian processors (years before
the advent of the PC) and I got acustomed to it. I am sure that
there also exist some supporters of PDP endianness :-)

	The reason why FORTRAN is still alive is the same: people
need a very strong reason to change their habits. But in this case,
obsolescence will solve the problem :-<

	With endianness, we've got a long-lived subject of dispute.
Therefore we may have centuries of fun reading the controversy and
looking at people enthusiastically devoting their time to the
conversion of kernels and applications from one endianness to
another :->

	Please guys, go on, I'm sure that many readers enjoy it !


Didier Kryn
College de France / LPCC, 11 Place M. Berthelot, 75231 Paris cedex 05


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