Re: GCC default CPUs

["Richard Earnshaw (lists)" <Richard.Earnshaw%arm.com@localhost>]

On 31/10/2018 05:15, Michael wrote:
> Hello,
> 
> On Tue, 30 Oct 2018 23:09:18 +0000
> Robert Swindells <rjs%fdy2.co.uk@localhost> wrote:
> 
>> coypu%sdf.org@localhost wrote:
>> >i'm upstreaming the netbsd eabi target to gcc upstream.
>> >a question came up about our choice of platform triplets (or is it
>> >fourlets?:)), there are quite many.
>> >
>> >armv4--netbsdelf-eabi
>> >armv6--netbsdelf-eabi
>> >armv7--netbsdelf-eabi
>> >arm*--netbsdelf-eabi ??  
>> 
>> Don't we have v5 too, I think it is what is chosen if you build for
>> 'earm'.
> 
> Yes.
> 
>> Needed for things like zaurus.
> 
> And some Marvell miniserver things, and Iyonix.
> Funny thing, I'll pick up an iyonix from the post office tomorrow.
> 
> How different are v4 and v5 anyway? I remember using a shark ( as in
> armv4 ) userland for the initial RPi1 port to get X going.
> 

v5 (strictly, v5t - there is no v5) has Thumb and so can properly
support the EABI, which requires use of blx/bx at call and return
points.  v4t also has thumb, but strongarm does not implement that.
v5t improves the interworking of Arm and Thumb code by allowing the pop
instruction to switch between the two instruction sets during a return.

v5te adds (amongst other things the ability to support VFP).

R.

> have fun
> Michael