Re: [Qemu-devel] [Qemu-riscv] [RFC v1 0/5] RISC-V: Add firmware loading support and default

[Andrea Bolognani <abologna@redhat.com>]

On Fri, 2019-06-21 at 14:35 +0200, Andrea Bolognani wrote:
> On Thu, 2019-06-20 at 21:43 +0300, David Abdurachmanov wrote:
> > On Thu, Jun 20, 2019 at 9:18 PM Alistair Francis <alistair23@gmail.com> wrote:
> > > OE-Core already packages OpenSBI by default, Fedora and Debian are
> > > moving to OpenSBI for RISC-V targets as well.
> > > 
> > > Any distro that supports the RISC-V toolchain (which is all
> > > upstreamed) can build OpenSBI.
> > 
> > Fedora uses OpenSBI for the last 2 or 3 months now. I don't plan to update
> > BBL builds. OpenSBI packages in Fedora/RISCV isn't finalized, but it does
> > ship *.elf and *.bin files.
> 
> Sounds good to me, thanks for confirming!

From further off-list discussion with David, I have learned that
recent Fedora images include an OpenSBI build with embedded U-Boot
payload, such that you only need to have that single file on the host
and pass it to QEMU via -kernel[1] for RISC-V guest boot to work. I
played with it over the past few days, and it works very nicely.

I think this is the result that we want to ultimately reach: a single
RISC-V "firmware" binary installed on the host through an appropriate
distro package, shared among guests, with everything else that is
guest-specific being contained in the corresponding disk image.

This is what other architectures are already doing, with SeaBIOS and
OVMF on x86_64, AAVMF on aarch64 and SLOF on ppc64 all being handled
this way: RISC-V should, where it makes sense, follow suit.

QEMU also recently introduced a JSON-based specification that can be
used to advertise guest firmwares and libvirt already supports it,
which makes firmware configuration either extremely convenient or
entirely automatic for the user: the OpenSBI support should also be
advertised this way.


[1] I guess that'd be -bios after these patches?
-- 
Andrea Bolognani / Red Hat / Virtualization