[colug-432] Fwd: Re: Debian on Pi

[Rick Troth]

> Does hard / soft float refer to, or lack of, a math coprocessor (fpu)?

Well ... *my* post does.  Not sure about the nature of ARM hard/soft float.

> Your reference to a 486 SX in regards to no math-co
> brought back a happy memory of populating a small socket with a Intel 387.

Exactly.
So this olde Compaq Presario that I have sports a "486 SX", distinct
from the "486 DX" of the time which *did* have the math co-processor.
(I believe in 486 packaging, the math co-processor was physically
integrated, no separate socket.)  I use the old beater for occasional
IPv6 experiments or demos.

It seemed relevant to the ARM/RPi discussion because supporting "soft"
387 was isolated to the kernel.  The pain of re-compiling dozens or
hundreds of apps as the Debian crew did ... ewww...  But as a
compatibility fiend, I very much appreciate the effort.

-- R; <><





On Mon, May 6, 2013 at 12:47 AM, FiL Farris <philipfarris at gmail.com> wrote:
> Does hard / soft float refer to, or lack of, a math coprocessor (fpu)?
>
> Your reference to a 486 SX in regards to no math-co brought back a happy
> memory of populating a small socket with a Intel 387.
>
> On May 6, 2013 12:17 AM, "Rick Troth" <rmt at casita.net> wrote:
>>
>> I'd like to hear more about this.
>>
>> Sounds like supporting "hard float" was/is way more complicated with ARM
>> than the hard/soft float support back in the pre-Pentium days.  I still have
>> a 486 "SX" which requires math emulation.  But on INTeL x86 series HW,
>> that's a boolean flag when building the kernel.  No need to re-compile the
>> apps.  (Unless I have missed something profound.)
>>
>>
>> -- R; <><
>>
>>
>>
>>
>> On May 5, 2013 12:11 PM, <lhowell at speakeasy.net> wrote:
>>>
>>>
>>> >The primary difference between the Raspbian and Debian images is that
>>> > Raspbian is hard-float and Debian is soft-float.  Debian will work fine, but
>>> > at the cost of a performance hit.  The Pi ARM11 hardware does well for what
>>> > it is, but needs all the help from the OS it can get so I'd choose HF.  I
>>> > followed the creation of Raspbian vian discussions on the debian-arm mailing
>>> > list, which was a six month effort as the Debian "wheezy" source for 35000+
>>> > packages was rebuilt for the ARM11 v6 ABI instead of the normal ARM9 v7 ABI.
>>> > Much of the time was spent fixing hard-float issues.  The Cambridge team was
>>> > very time constrained and chose the more expedient path of building with
>>> > soft-float.
>>> >My wife gave me two Pi's for Christmas.  One is my media server running
>>> > the Pi version of openELEC (openelec.tv) and I used to other one to pass the
>>> > Kalamazoo winter evenings experimenting with different OS images.  If you
>>> > want a minimal headless OS I suggest looking at
>>> > http://www.pi-point.co.uk/raspbian-minimal/ which is the standard Raspbian
>>> > HF image with about 75% of the packages stripped.  You can start small and
>>> > add whatever you like from the Raspbian repo.
>>> >SD cards are a sticky issue, and a discussion for another time.  The Pi
>>> > demands quality cards.  I've had good luck with SanDisk Mobile microSDHC 4GB
>>> > cards (4.99 at MC).  I don't worry too much about the class rating.  That
>>> > rating criteria is for handling relatively large files on cameras, not the
>>> > much smaller files on an embedded device like the Pi.
>>> >
>>> >Larry
>>> >
>>> >
>>>
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>>
>>
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-- 
-- R;   <><