Re: qemu direct kernel boot on LoongArch

["Jason A. Donenfeld" <Jason@zx2c4.com>]

On Thu, Sep 05, 2024 at 04:54:41PM +0200, Jason A. Donenfeld wrote:
> On Thu, Sep 05, 2024 at 02:11:32PM +0800, maobibo wrote:
> > 
> > 
> > On 2024/9/5 下午1:25, Thomas Weißschuh wrote:
> > > On 2024-09-05 06:04:12+0000, Jason A. Donenfeld wrote:
> > >> On Thu, Sep 5, 2024 at 5:45 AM maobibo <maobibo@loongson.cn> wrote:
> > >>>
> > >>> Jason,
> > >>>
> > >>> With the latest qemu 9.1 version, elf format booting is supported.
> > >>
> > >> Thanks, I just figured this out too, about 4 minutes ago. Excellent.
> > >> And the 1G minimum ram limit is gone too.
> > >>
> > >> Now working on how to trigger resets.
> > > 
> > > With "reset" do you mean normal (non-panic) system shutdown/poweroff?
> > > Since QEMU 9.1 and a recent kernel you can use the pvpanic device for
> > > that in a cross-architecture way.
> > LoongArch uses acpi GED device to reboot machine. Now there is no FDT 
> > table description and FDT driver for acpi GED device :(
> 
> So you mean that QEMU exposes it via ACPI, but not via FDT, and the
> kernel doesn't know how to recognize it, even with ACPI?

Ahh, it looks like QEMU exposes it via ACPI, but ACPI is broken (?) when
booting directly from ELF. So it needs to be exposed via FDT instead? Or
ACPI needs to be fixed with direct ELF boot?