Aarch64 system registers known to binutils

[Kyrylo Tkachov]

Hi Jan,

> -----Original Message-----
> From: Binutils <binutils-bounces@sourceware.org> On Behalf Of Jan Beulich
> Sent: 16 July 2020 13:36
> To: Richard Earnshaw <Richard.Earnshaw@arm.com>; Marcus Shawcroft
> <Marcus.Shawcroft@arm.com>
> Cc: Binutils <binutils@sourceware.org>
> Subject: Aarch64 system registers known to binutils
> 
> Hello,
> 
> some time after seeing a051e2f3e0c1 ("[AArch64][gas] Update MTE system
> register encodings") I went and checked my own disassembler as well as
> gas against the doc, and I think there are a number of omissions in
> binutils. The question is whether this is intentional, and registers
> get added only as people find a need for having a (direct) way to
> access them by name, or whether omissions here are to be considered
> bugs.
> 
> Thanks for any insight,

As far as I know, it is a missing feature and personally I'd be happy to see binutils support more of them as defined in the reference material: https://developer.arm.com/docs/ddi0595/h
Note that some system registers are only accessible at certain architecture levels and extensions and should be diagnosed as such when used with unsuitable command-line options.
Some registers are also read-only or write-only and gas has infrastructure to diagnose bad uses of such registers.

Thanks,
Kyrill

> Jan