Re: [PATCH v3 0/1] Add support for generating OpenSBI domains in the device tree

[Andrew Jones <ajones@ventanamicro.com>]

On Mon, Sep 09, 2024 at 01:27:05PM GMT, Alistair Francis wrote:
> On Tue, Aug 6, 2024 at 7:05 AM Gregor Haas <gregorhaas1997@gmail.com> wrote:
> >
> > This patch series adds support for specifying OpenSBI domains on the QEMU
> > command line. A simple example of what this looks like is below, including
> > mapping the board's UART into the secondary domain:
> 
> Thanks for the patch, sorry it took me so long to look into this
> 
> >
> > qemu-system-riscv64 -machine virt -bios fw_jump.bin -cpu max -smp 2 -m 4G -nographic \
> >         -device opensbi-memregion,id=mem,base=0xBC000000,order=26,mmio=false \
> >         -device opensbi-memregion,id=uart,base=0x10000000,order=12,mmio=true,device0="/soc/serial@10000000" \
> >         -device opensbi-domain,id=domain,possible-harts=0-1,boot-hart=0x0,next-addr=0xBC000000,next-mode=1,region0=mem,perms0=0x3f,region1=uart,perms1=0x3f
> 
> This will need documentation added under docs (probably under
> docs/system/riscv) of how this should be used.
> 
> I'm not convinced this is something we want though. A user can dump
> the QEMU DTB and edit it to support OpenSBI domains if they want.
>

I also feel like this is just pushing the population of device tree
nodes from an editor of a .dts file to the QEMU command line. If some
generation is needed, then maybe we need a script, possibly one which
has the same command line inputs as proposed here. afaik, we haven't
typically taken patches which help overlay the generated devicetree
with additional nodes. For example, see [1] for one such proposal
and rejection.

[1] https://lore.kernel.org/all/20210926183410.256484-1-sjg@chromium.org/

Thanks,
drew