[Arm-netbook] RedSleeve - New ARM Linux Distro

[Barry Kauler]

> Have you actually looked at what the realistic performance advantage is
> on something like a Tegra2 between running armv5tel and armv7hl for a
> typical desktop workload? It's not all that much. Not to mention that
> the GPU drivers and proprietary DSP libraries for most ARMs (the closed
> ones since there are no open ones) are only available for the soft-float
> target.

I would have to chase up comparisons that I have read. Can't recall
all the details off the top of my head...

I do recall that ARMv7 thumb-2 instructions offer significant
reduction in executable size (and speed) -- unlike thumb-1 which isn't
very usable.

I should add that Ubuntu 12.04 will have ARMv7 hard-float binary packages.

I intend to compile some multimedia apps with NEON turned on,
especially for my target hardware (A10).

Um, I found one of the reference docs that I had previously read:

http://wanderingcoder.net/2010/07/19/ought-arm/

...they reckon that NEON is in all the ARMv7-based chips that they
have encountered.
...no timing comparisons on that site.

My thinking is that we have to try and extract maximum speed wherever
we can with these chips, to get apps to have acceptable
responsiveness. A little bit here, a little bit there, it adds up.
Thumb-2 is one of those important "little bits".

I guess that I am being more hardware-specific than Red Sleeve. I am
thinking in terms of ARMv7 +NEON and Mali GPU -- latter has drivers, a
complete open source project for the GPU (kernel, openGL and
X11drivers) is well underway. But perhaps that's what we need to be,
fairly narrowly targeted, given the lack of standardisation (and so
much closed up/secret) of ARM-based hardware.

...which is why I reckon the planned T2 port to the A10 is going to be great.

Just my thoughts, I am still a newcomer to ARM.

Regards,
Barry Kauler