> Ubuntu got in touch with us to say ‘how can we stop you saying that Ubuntu runs on Raspberry Pi?’ Which I thought was pretty brutal, actually. So, yeah: they don’t support our chip, they’re not interested in supporting our chip, they’ve been quite vocal about trying to stop us from saying Ubuntu, so we stopped saying Ubuntu.
Way to go, Canonical...
You want to make Ubuntu the Linux desktop, yet you can't be arsed to support one of the cheapest and easiest solutions to run it on?
The Raspberry Pi is a brilliant way to introduce children and adults alike to linux, and Ubuntu doesn't deem it worthy of supporting that effort...
In their defense, ARM11 is a 10 year old chip. I don't think they want to support such an old legacy. Does Windows 7 support Pentium 2?
Still, I'm hoping Raspberry Pi moves to Cortex A7 as soon as it's available, which is based on the ARMv7 architecture, and Canonical might support it then.
Debian has two ARM ports: one that supports ARMv4 and newer, and a second that supports ARMv7. It looks like Fedora is pursing the same approach. If they have the expertise and resources to do this, surely Canonical could do it too if they thought supporting older ARM devices would benefit them.
The PII is 15 years old at this point, 10 years ago was Northwood p4 and the Athlon XP for AMD
Those chips started at 1.6 and 1.33GHz respectively, and Windows 7 requirements start at 1GHz. RAM might be a dicier issue (W7 requires 1GB) and I don't know the state of the chipset drivers, but technically W7 probably supports x86 chips from 10 years ago.
i586 has stayed backwards-compatible (although performance isn't the same if you don't know what you're targeting), ARM hasn't. The raspberry pi's ARMv6 is very different from a Cortex's ARMv7. The kernel also needs patches to know how to initialise an ARM device, and those patches need to be forward-ported.
Canonical is in a tough spot. They've put a lot of resources into developing a new desktop environment and branding that as Ubuntu. That desktop isn't going to run on a 700mhz ARM11 with 256MB of RAM.
I think Canonical suffers from NIH syndrome. They've displayed that tendency in the past. And they're on their way with their own ARM stack with the Boot-from-Android thing announced and I assume a few other things in the pipeline, so Raspberry Pi is competition they probably would prefer to do without.
What's Canonical playing at? Surely the Raspberry Pi represents a golden opportunity to steal massive amounts of mind share. They could establish themselves as the computing environment amongst the next generation of computer users.
"Ubuntu got in touch with us to say ‘how can we stop you saying that Ubuntu runs on Raspberry Pi?’ Which I thought was pretty brutal, actually."
As a HW engineer he overlooked hidden software complications with ARMv6 chipset. The ARMv6 chipset is old, its virtually tagged/indexed caches have a plethora of cache aliasing issues that reflect to workarounds in linux kernel and shared libraries in userspace. You have to maintain an entire ARMv6 distro for this arch. I would personally not use anything non ARMv7, because all these issues are resolved in ARMv7.
So its quite natural Ubuntu did not want to allocate a team of 100k/year engineers for raspberry pi, and protect its brand also.
For the curious, if you map the same physical address to 2 virtual addresses, and both happen to be in the cache, you have 2 virtual entries in the cache for the same address, so which one to flush back to RAM is ambiguous. Its a problem specific to virtually addressed caches. Solution: a lot of restrictions to avoid aliasing and you flush the caches too often to avoid aliasing etc.
Thanks for explaining. Ubuntu's approach makes sense then. Wonder how much more expense v7 would have been.
I see the problem with Raspberry Pi being the software and the SDK. It is a very elegant and appealing piece of hardware but that only gets them there half way. The other is the manuals, the sdk, some kind of recipe exchange or cookbook for basic things.
Also, it looks like Arch Linux has stepped up to replace Ubuntu.
Once it has USB, Ethernet, and HDMI it is not your uncle's bare 8 bit micro-controller anymore. Yeah developers could sit and each write a different version of HDMI driver, but wouldn't be too much fun. One would expect there to be a nice SDK and libraries to access and make use of all those hardware features.
If I remember correctly, one of the chips they had in mind when designing the board was no longer in production, or the price had gone up.
Actually, I looked it up and yes, one of their components had been replaced and they had to design for the new version.
http://www.raspberrypi.org/archives/615
-edit: sorry, after re-reading it, it doesn't seem like they designed for the new one, they just had to wait while the factory found enough of the old version. But that's why it was delayed.
Par for the course in the hardware world, one of the reasons why I'm very happy my soldering iron has retired.
The probability of a chip being eol'd for <insert random reason here> is inversely proportional to the number of pin compatible replacements made by alternate sources.
And that makes perfect sense: If something is essentially guaranteed to sell well, competitors would produce it as well. If something is not selling well enough to produce compatible replacement, then it is likely marginally profitable to produce or not at all.
Way to go, Canonical...
You want to make Ubuntu the Linux desktop, yet you can't be arsed to support one of the cheapest and easiest solutions to run it on? The Raspberry Pi is a brilliant way to introduce children and adults alike to linux, and Ubuntu doesn't deem it worthy of supporting that effort...