Fedora Remix or Debian?


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by semtex » Sun Mar 04, 2012 2:42 am
While we patiently wait for our RasPi I thought I would prepare the SD card.

I know there are lots of different options (RiscOS is quite appealing... anyone for Zarch??) but are there any significant differences between Fedora Remix 14 and the Debian system on the element-14 site http://www.element14.com/commu.....spberry-pi?

Thanks
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by semtex » Sun Mar 04, 2012 2:50 am
Ahh... I'm going to answer my own question!

I've discovered http://elinux.org/RPi_Distributions is a great resource for the different OSes. Debian ARM was used with the alpha boards but the Fedora Remix appears to be the recommended distro.
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by sorinm » Sun Mar 04, 2012 8:28 am
I`m not new in linux world. I`m using the tux since 2001 when redhat was free and mandriva was mandrake :) . I would like to see Slackware`s arm port (ArmedSlack) on my raspberry pi but we will need to wait ..

Debian is the most robust linux, it releases a new version every two years. In these two years before being released, the packages are tested and tested and patched and again tested. It`s rock solid but with a price, you won`t have cutting edge versions of the software. It`s a more server/workstation orientated distro. A very big plus is that Debian has one of the largest package repository.The apt package manager is one of the best package management systems.

Fedora is a more home/multimedia orientated distro. Until other distributions rise, Fedora will be my choice because I`ll use my Pi mainly for multimedia applications.

I`m still hoping Armed Slack will be released for Pi, Sysvinit scripts just annoy me ;)
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by pepedog » Sun Mar 04, 2012 9:22 am
Have you seen http://archlinuxarm.org/
Also seen gentoo running on a pi
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by sorinm » Sun Mar 04, 2012 9:44 am
I like archlinux because it combines almost perfectly simplicity and functionality. It`s a clean and stable distro.

When a raspberry pi image will be available I will give it a shot.
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by pepedog » Sun Mar 04, 2012 11:16 am
Archlinuxarm has had a rootfs download available since 26th of November.

The 3rd incarnation is ready on these mirrors and waiting for it to appear on downloads page. There is a torrent link but it's on my iPad.
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by sorinm » Sun Mar 04, 2012 11:33 am
I`ll download the rootfs and try when my pi will arrive. Are you planning to make a dd image with a GUI?

Armed slack also has a rootfs: ftp://ftp.armedslack.org/armed.....otfs/roots . I`m curious if will boot ..

L.E. Found your DD image :)
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by esbeeb » Wed Mar 07, 2012 4:33 pm
semtex said:


are there any significant differences between Fedora Remix 14 and the Debian system


Yes, there will be a huge difference.  Remember how the guys at Seneca College painstakingly compiled Fedora specifically for the Raspberry Pi's ARMv6 CPU?  Thanks to doing that, all those Fedora software packages will have an important-to-multimedia optimization, called "hardfloat", compiled in.  Those software packages are able to take advantage of the ARMv6's built-in "floating point"-processing hardware.

But Debian's software packages, as they currently stand, were unfortunately compiled in a more generic fashion such that "hardfloat" is NOT compiled in.  Therefore all floating-point-intensive applications (especially multimedia) will instead do their floating point calculations using software emulation, incurring a rather major performance loss (something like 40%).  The hardware-based floating point abilities of the Raspberry Pi will currently just sit there, effectively unusable, in Debian.

For more details, including a suggested course of action to fix this, please see this post.  Basically, if Debian fans realistically want Debian on the Raspberry Pi, they are going to have to stand together and work for it, and do whatever it takes to get "hardfloat" compiled into all the Debian packages.

The distros such as Arch, which do a "just-in-time" compilation of software (at installation time), will also gain the "hardfloat" optimization, although it must be pointed out that the "just-in-time" compilation can be VERY time consuming, lasting as long as DAYS, for larger software packages (including all their software dependencies).  But those distros have the up-front advantage of saving the effort of building, staffing and maintaining a "build cluster".  They "outsource" the effort of compiling onto the end user.  They don't need a team (equivalent to the guys at Seneca College), pre-compiling all the software packages for the end users.

Distros like Arch or Gentoo aren't very popular in the PC world, because all the time it takes to compile the software "just-in-time" typically only yields a performance gain of about 1 or 2% (in comparison to installing pre-compiled packages, compiled in a more generic manner).  But in the world of ARM processors, where the hardware capabilities vary A LOT from processor to processor (within the ARM product line), their "compiled-just-in-time" philosophy really shines (granted you are willing to wait as long as it takes to compile, at installation time).  Perhaps those distros have finally found their true niche, in the ARM world.
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by AlexPT » Wed Mar 07, 2012 4:39 pm
So Fedora would be the better option for multimedia and web-surfing ?

At last for now... :)
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by esbeeb » Wed Mar 07, 2012 5:34 pm
I think the two real "user-friendly" contenders for newbies to pick from (when it comes to choosing a distro for the Raspberry Pi) are looking like they're going to be the Fedora Remix and Puppy (which has a long-standing reputation of squeezing the most from 256 MB RAM).

Having said that, we can speculate all we want ahead of time, but it remains to be seen which distro actually offers the better experience, once the Raspbery Pi boards actually get into the hands of the end users.

And remember, it may take months and months and months for each distro to work out all the major bugs, as users discover them.  At this time, anyone expecting their first Raspberry Pi experience to be a "polished" one is in for a rude awakening!

In the meantime, anxiously curious end users might do well to get at least a couple of known-to-be-trustworthy, cheap SD cards on hand, so they can easily switch between trying each contending distro, when their Pi arrives.
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by esbeeb » Fri Mar 09, 2012 4:56 pm
Breaking news!

Good news for Debian fans: It would seem that the Debian ARM porters are now actively discussing (on the "Debian port to ARM" mailing list) how to go about making some kind official Debian port for the Raspberry Pi.  Unfortunately, as of yet, none of them have any Raspberry Pi hardware (or remote login access to any).  Hint: Anyone wanting to help them out by allowing them the use of their Raspberry Pi for compiling packages would probably be helpful and appreciated! :)

If and when this "official port" occurs (and it seems very likely, so it's probably just a matter of time now), then gaining "official" support by the Debian project would mean alot, and IMHO, it will be a huge advantage, effectively making it top contender as "distro of choice" for newbies on the Rasberry Pi.

Why?  Because "officially"-supported Debian ports, being "first class citizens" (in the Debian parlance), get "Security Update" software packages covered "automagically" (just like all the other "official" Debian ports).  This means that no little band of newly-volunteering Raspberry Pi users would have to try to keep up with publishing all the Security Updates in a timely and comprehensive manner, hoping that one day Debian proper would officially take over that serious responsibility.

In other words, Debian would gain the advantage (over the Fedora Remix) of having reliable, trustworthy Security Updates covered by Debian proper (who have a pretty-much excellent reputation for treating Security Updates seriously and properly).

The Fedora Remix, OTOH, as it currently stands, does not have this "first-class-citizen" status with Fedora (or "primary architecture" status, as they call it), and Fedora proper will therefore not be covering the Fedora Remix's Security Updates for at least about 9 months (ie. two releases from now), if not longer (by their own estimation). For more info, see this post, and replies.  Having Security Updates covered at the outset (of the Raspberry Pi hitting the scene, into the hands of users) does not seem to be a high priority for them, at it stands currently.

Long story short, if you're a newbie, and you care about Security Updates, and you don't want to wait for packages to compile themselves at installation time, and you want the largest selection of software packages, by far (Debian currently has well over 30,000 easily-installable software packages, which is roughly about twice that of Fedora), then I think Debian will soon be the best default choice (with Puppy being the "dark horse" which might also be worth paying attention to).
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by jojopi » Fri Mar 09, 2012 5:44 pm
esbeeb said:

Remember how the guys at Seneca College painstakingly compiled Fedora specifically for the Raspberry Pi's ARMv6 CPU?  Thanks to doing that, all those Fedora software packages will have an important-to-multimedia optimization, called "hardfloat", compiled in.  Those software packages are able to take advantage of the ARMv6's built-in "floating point"-processing hardware.

I do not think they ever claimed to have done such a thing.  And they certainly do not appear to have done so.  Of the 620 packages in the fedoremix, 540 are compiled for armv5tel and 80 are noarch.

According to the Seneca wiki, the future fedoremix 17 is also planned to be for armv5tel.

Bottom line is that none of the big distros currently support armv6 optimally, with or without float.  Not even for key packages like glibc.
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by esbeeb » Fri Mar 09, 2012 8:23 pm
esbeeb said:


In other words, Debian would gain the advantage (over the Fedora Remix) of having reliable, trustworthy Security Updates covered by Debian proper (who have a pretty-much excellent reputation for treating Security Updates seriously and properly).


Correction: I said "would gain the advantage ... of having reliable, trustworthy Security Updates covered by Debian proper", which implies that Security Updates are not covered now.  To my understanding, Security Updates ARE already well-covered in the current Debian download for the Raspberry Pi (since the packages are from the "armel" port, being officially supported).

The difference I'm highlighting here, which would take Debian from "good" to "awesome", IMHO, is that packages that ought to be compiled with hardfloat are currently not.
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by esbeeb » Fri Mar 09, 2012 8:50 pm
jojopi said:


I do not think they ever claimed to have done such a thing.  And they certainly do not appear to have done so.


I heard a vague reference (somewhere in this forum) that the Fedora Remix packages would somehow run faster than the Debian packages.  So I guess I assumed they compiled them in the obviously sane manner of ARMv6 with hardfloat.  Sorry, but after about 15 minutes of digging around, I can't find that reference.  But the response was to one of my Fedora-Remix-related questions.


Of the 620 packages in the fedoremix, 540 are compiled for armv5tel and 80 are noarch.

According to the Seneca wiki, the future fedoremix 17 is also planned to be for armv5tel.


I don't suppose you could reply with links to that?  I've asked them for clarification in the Fedora Remix distribution forum.


Bottom line is that none of the big distros currently support armv6 optimally, with or without float.  Not even for key packages like glibc.


I'm optimistic that the Debian folks will pull through with some hardfloat-compiled-goodness, after watching their discussions.
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by rmm200 » Fri Mar 09, 2012 8:54 pm
For those of us with too much time on our hands, is it feasible to rebuild the distro optimized for armv6 with hardfloat? Either Debian or Fedora Remix?

Any link on how to do this? Rebuilding 620 packages does not sound too bad, and I have a month before seeing hardware...
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by esbeeb » Fri Mar 09, 2012 9:01 pm
BTW: If the Fedora Remix is compiled for ARMv5 with hardfloat support, I'm pretty sure that's virtually just as good as ARMv6 with hardfloat support.  I've heard that to gain hardfloat support is a much more noticeable gain than compiling for ARMv6 (instead of more generically for ARMv5).

That might explain things.  We'll see.
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by ulysses » Fri Mar 09, 2012 9:20 pm
rmm200 said:


For those of us with too much time on our hands, is it feasible to rebuild the distro optimized for armv6 with hardfloat? Either Debian or Fedora Remix?

Any link on how to do this? Rebuilding 620 packages does not sound too bad, and I have a month before seeing hardware...



If you have time on your hands, and want to learn plenty about Linux, you could always try Linux from Scratch, available at linuxfromscratch.org.
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by rmm200 » Fri Mar 09, 2012 10:48 pm
Thank you very much for that link!

linuxfromscratch.org looks like a really well organized site, suitable for a good

college course.

I saw a linux kernel reference from Liz which she said is hosted on Github.

Do you have a link for that? I need that for the Pi specific drivers.
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by jui-feng » Fri Mar 09, 2012 11:02 pm
This is the raspberry kernel repository at github AFAIK: https://github.com/raspberrypi/linux
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by error404 » Fri Mar 09, 2012 11:17 pm
esbeeb said:

Hint: Anyone wanting to help them out by allowing them the use of their Raspberry Pi for compiling packages would probably be helpful and appreciated!

So Debian was an early contender for 'official' status and nobody reached out to them with some alpha/beta hardware. But they sent some to the XBMC developers? Great.

For my own purposes, I'm definitely going with Debian. Most of what I expect to use it for is not floating-point heavy, and Debian is by far my favourite distribution for headless tasks (and many headed ones). Even better if folks there plan to do an official ARMv6 port.
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by mpthompson » Fri Mar 09, 2012 11:24 pm
rmm200 said:


For those of us with too much time on our hands, is it feasible to rebuild the distro optimized for armv6 with hardfloat? Either Debian or Fedora Remix?

Any link on how to do this? Rebuilding 620 packages does not sound too bad, and I have a month before seeing hardware...


I've made some effort to look into this and even started asking questions on the debian-arm email list.  I'm pretty familiar with Linux from a programming standpoint, but a rank beginner when it comes to understanding Debian packaging what such an effort might entail.  Quite frankly, it's a bit intimidating.  However, I'm making some progress in learning 'the lay of the land' so to speak.

There are many different approaches that can be taken.  For instance, an easier approach would perhaps be to recompile a handful of key Debian packages that would benefit greatly from the VFP, but maintain the armel softfp EABI so that the packages would remain fully compatible with the existing armel distribution.  These packages could then be maintained in an unofficial repository and people who want hardware floating point could pull from that repository as needed by tweaking their sources.list file for the apt packaging tools.  The armel EABI has some inefficiencies as floating point values are passed between functions in integer registers, but there would still be a substantial improvement in performance for packages with significant floating point operations.

At the other extreme would be to take the armhf port, tweak the optimizations to support the more efficient hard float ABI, ARMv6, VFP and not support Thumb2 instructions and compile the whole port.  The challenge here is that the armhf is targetting ARMv7 and the recompiled port would have to be carefully checked to make sure no ARMv7 code snuck through the build process.  Particularly problematic would be packages that include ARMv7 Thumb2 assembly as those would be a bit of a challenge to backport to ARMv6 assembly.

Depending on the approach taken, it could be several man-weeks of work to perhaps a few man-years worth of work.  I don't yet know enough to know where the biggest bang for the effort expended would be.

If others are interested in pursuing this, perhaps we should start an email list to begin discussing this further.  I would consider help funding a build cluster to create a repository of RPi optimized Debian packages, but that would be contingent upon feeling the effort would be successful and worthwhile.
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by mpthompson » Fri Mar 09, 2012 11:38 pm
error404 said:

So Debian was an early contender for 'official' status and nobody reached out to them with some alpha/beta hardware. But they sent some to the XBMC developers? Great.
For my own purposes, I'm definitely going with Debian. Most of what I expect to use it for is not floating-point heavy, and Debian is by far my favourite distribution for headless tasks (and many headed ones). Even better if folks there plan to do an official ARMv6 port.


I have a similar predilection towards Debian.  It's simply what I know best and the community support and wealth of information on the web is tremendous.  My preference would also be to use Debian for anything I do with the RPi, but I'm seriously considering learning more about Fedora as that is where the momentum looks to be.

I'm not sure the issue is the availability of hardware as the the RPis would likely make very poor build machines for pounding through package compilation.  Rather you would want to use an array of something like the Freescale i.MX535 Quick Start board for $149 to compile optimized ARM packages:

http://www.freescale.com/webap.....e=IMX53QSB

This has 1GB memory, a 1GHz processor and SATA interfaces for efficiency in communicating with the disk.  I'm assuming that ARMv6+VFP code optimized for the RPi would run fine on this dev board.

Instead, the decision that armhf would not support ARMv6+VFP was made by the community after weighing the cost/benefits of the work required to actual make the armhf port.  I believe these decisions were made before the RPi came on the scene as the armhf has been in the works for quite a while now.
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by esbeeb » Fri Mar 09, 2012 11:51 pm
rmm200 said:


For those of us with too much time on our hands, is it feasible to rebuild the distro optimized for armv6 with hardfloat? Either Debian or Fedora Remix?

Any link on how to do this? Rebuilding 620 packages does not sound too bad, and I have a month before seeing hardware…

If you want to learn the "Debian way" of building packages, they already have high-level custom tools to automate this as much as possible.  From this recent post, 
it's explained (to Mike Thompson, who also wants to learn how to build Debian packages):

> I presume that
> Reprepro+rebuildd+sbuild is what would make the build of the RPi tuned
> respository possible.

Yes, they are build tools:

* Sbuild builds packages on buildds.
* reprepro is the package repository which has all the package lists,
and the package pool.
* rebuildd is a simple build-daemon. It's a bit dim for running a whole
distro-build system with, but it's approximately 100 times easier to
set up than wanna-build + buildd which are the standard Debian tools.

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by esbeeb » Sat Mar 10, 2012 12:13 am
mpthompson said:


Rather you would want to use an array of something like the Freescale i.MX535 Quick Start board for $149 to compile optimized ARM packages:

http://www.freescale.com/webap.....e=IMX53QSB


If anyone wanted to buy some of these to help compile Debian packages, I sure wouldn't want to stop them.

But perhaps another option to also consider is this: I wonder if "crowd-sourcing" from the Raspberry Pi community itself (once the first 10,000 units hit the scene) might be feasible to assemble a large-enough, loosely-knit farm of Debian-package-compiling machines.

After all, when the original Debian image for RPi was posted for download, about 35ish download mirrors appeared in about 2 days, without anyone even asking for help (AFAIK).  This would suggest that there are many people out there already willing to help Debian in whatever way they can.

This is just idle talk, but perhaps if reliable, easy-to-follow directions, or better yet, a script, were/was assembled and posted (as how to set up Reprepro+rebuildd+sbuild), then it would be easy for volunteers to set up their RPi's to "join the build farm". Perhaps the assembly of such instructions might be a great use of time, while we wait for those first 10,000 units to hit the scene.
And perhaps just a few of those Freescale units, in the meantime, might go a long way for someone wanting to do a real trial run of learning
Reprepro+rebuildd+sbuild, so that the instructions could be verified as working.
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by esbeeb » Sat Mar 10, 2012 12:21 am
BTW: Naturally, Debian has their own servers for building.  And, as we all know, no Raspberry Pis are in that list yet.

I wonder if RPi owners wanting to help out can somehow add their Raspberry Pi's to their machine database.  After all, for best results, I've heard the packages should be compiled on exactly the same hardware they will run on (ie. Raspberry Pis), just to be safe.  And it might take a lot of Raspberry Pis, considering that there are over 30,000 packages in Debian.  In comparison, the Fedora Remix seems to have compiled only several hundred packages, themselves.

From the "Debian Arm Port" page:


Available Hardware for Debian Developers

agnesi.debian.org (arm) and agricola.debian.org (armel) are available to Debian developers for ARM porting work. The machine have development chroot environments which you can access with dchroot. Please see the machine database for more information about these machines.

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