[PATCH] arc: Add support for ARC HS extra registers in core files

[Shahab Vahedi]

Hi Claudiu,
 
> > 
> > Hi Shahab,
> > 
> > I don't really like the ARC_V2 name. All ARC variants can have extra registers
> > from r32 to r59 called extension core registers :) I would go for something more
> > generic like ARC_EXT_REG, or something like that
> > 

I have looked into this a little bit further:

As Anton mentioned, since NT_ARC_V2 is entangled with kernel's ptrace, it is
not a not a viable option to change it.

Regarding the ".reg-arc-v2" section, there can be 3 registers in there: r30,
r58, and r59. The r58/r59 pair are the accumulator registers. r30 is the tricky
one. In ARCompact (ARC 600/700), r30 used to be called ILINK2 and was not a
userspace register. In ARCv2, that has changed. It is considered a general
purpose register, hence its inclusion in ".reg-arc-v2". I am afraid that the
name of this note indeed reflects how tied it is to ARCv2.


Cheers,
Shahab