Re: Identification of ARM chips
+++ Hector Oron [2010-01-23 00:49 +0100]:
> Hi,
>
> 2010/1/23 Neil Williams <codehelp@debian.org>:
> > I get confused about the different ARM types and which map to armel.
>
> What I understand is that 'armel' (EABI) is a feature on the
> instruction set that a CPU is able to execute, since armv4t
> instruction set in all processors ever since arm9 (and some arm7) are
> able to execute EABI instructions.
Even that isn't quite right. Nothing about EABI requires a particualr
CPU. However the _implementation_ in gcc/binutils requires an armv4t
or later instruction set, because EABI needs an atomic function in order
to support switching between arm and thumb instructions (IIRC), and
eabi supports this mixing of thumb and arm on a per-function basis.
It was difficult to do this for armv4 and earlier (v3) instruction-set
CPUs, and as they are all (?) pretty-much obsolete no-one made the
effort to actually do that.
So that's the long version. The short version is: you need armv4t or
later for armel. I haven't been keeping up recently but I think
everything being produced which has enough welly to run linux is at
least arm v5 these days.
I don't know most of the CPUs in the list, but lookng up the
instruction set they have will tell you if any are so ancient as to be
armel-incompatible.
Wookey
--
Principal hats: iEndian - Balloonboard - Toby Churchill - Emdebian
http://wookware.org/
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