[Arm-netbook] RedSleeve - New ARM Linux Distro

[Gordan Bobic]

Barry Kauler wrote:
> On 3/25/12, Gordan Bobic <gordan at bobich.net> wrote:
>> Hi guys,
>>
>> Just in case anyone here is interested in taking it for a spin, the
>> distro is now on proper alpha release. I am calling it alpha purely
>> because the packages aren't signed yet - other than that, I have been
>> using it for the past few months on my AC100 and various Kirkwood based
>> devices. The reason the announcement hasn't been made sooner is because
>> I had to strip out all the branding from the upstream distro that RS is
>> based on (because the upstream doesn't exist for ARM).
> 
> You have it running on the DreamPlug, which is an ARMv5 CPU I think.

Indeed.

> For me personally, I am setting the minimum at ARMv7, as even the
> cheapest smartphones these days have that. It has become the
> entry-level for Android phones. And of course the Cortex A8 also has
> the NEON multimedia instruction set, which is not part of the base
> ARMv7 spec.

Not quite true re: smartphones. My ZTE Blade has an ARMv6 in it, and the 
performance is perfectly OK.

> So, I am planning on using Ubuntu 12.04 Precise Pangolin ARM port.
> 
> Just my personal response, others might want to set the bar lower.

The problem is that there are a LOT of ARMv5 and ARMv6 devices out 
there, and targetting ARMv7 soft-float doesn't actually gain you all 
that much. Hard-float ARMv7 does gain you some extra performance, but 
only on FP-heavy applications.

There is also the fact that in the tool chain used on el6 hasn't good a 
sufficiently bug-free hard-float support, so targeting ARMv7 HF isn't an 
option. The primary point of the distro was to have EL6 for ARM. I don't 
see HF as a being particularly high on the requirements list, especially 
since some of the benefit comes from NEON - which doesn't exist on some 
ARMv7 CPUs.

So if you go down that route, you have to have at least three distros: 
armv5tel, armv7hl, and armv7hl+neon. That means three times the amount 
of work for what isn't going to be a great deal of benefit at the 
moment, at least while dropping armv5tel support isn't a viable option.

Gordan