Re: [RFC PATCH 0/5] gdb/aarch64: Support for FPMR

[Ezra Sitorus <ezra.sitorus@arm.com>]

> Hello Ezra,

Hi!

> Thank you for these patches.
> 
> <Ezra.Sitorus@arm.com> writes:
> 
> > From: Ezra Sitorus <ezra.sitorus@arm.com>
> >
> > The Floating Point Mode Register (FPMR) determines the behaviour of FP8
> > instructions. This patch series adds support for this register into gdb.
> >
> > This has been tested using Shrinkwrap, which allows me to run Linux on a
> > model of an Arm system with new features. You can find more information
> > here: [1].
> 
> Is there something specific one has to do to enable FPMR on
> Shrinkwrap/FVP?
> 
> I tried building an Armv9.5 configuration:
> 
> $ shrinkwrap build --overlay=arch/v9.5.yaml ns-edk2.yaml
> 
> and then running it with upstream kernel v6.16-rc7 which I think should
> support FPMR, but AT_HWCAP doesn't have the FPMR bit set, and the test
> program from the allow_aarch64_fpmr_tests procedure gets a SIGILL so the
> testcases in this series report unsupported.
> 
> -- 
> Thiago

I think that kernel version is fine. To get FPMR to work, I created an overlay.yaml
file which contains this:

run:
  params:
    -C cluster0.has_fpmr: 1

Then I run with this:

shrinkwrap run ns-edk2.yaml --overlay overlay.yaml

FYI, if you want to enable other features, you can see the options by doing:

docker exec <docker container name> FVP_Base_RevC-2xAEMvA --list-params

Ezra