Re: [PATCH] hw/riscv: virt: Enable booting S-mode firmware from pflash

[Sunil V L]

On Mon, Sep 05, 2022 at 10:07:22AM +0200, Andrew Jones wrote:
> On Mon, Sep 05, 2022 at 09:59:40AM +0530, Sunil V L wrote:
> > To boot S-mode firmware payload like EDK2 from persistent
> > flash storage, qemu needs to pass the flash address as the
> > next_addr in fw_dynamic_info to the opensbi.
> > 
> > Update the kernel_entry with the flash address when no kernel
> > is specified via QEMU command line  so that opensbi
> > can jump to the flash address. This assumes flash drive unit 1 is
> > used to keep dynamic payload similar to other architectures.
> > 
> > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > ---
> >  hw/riscv/virt.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> > index ff8c0df5cd..1ee855fded 100644
> > --- a/hw/riscv/virt.c
> > +++ b/hw/riscv/virt.c
> > @@ -1284,6 +1284,18 @@ static void virt_machine_done(Notifier *notifier, 
> > void *data)
> >          start_addr = virt_memmap[VIRT_FLASH].base;
> >      }
> >  
> > +    if (drive_get(IF_PFLASH, 0, 1)) {
> > +        /*
> > +         * Assume second pflash unit (unit=1) to hold the S-mode firmware
> > +         * like EDK2. Set kernel_entry to flash address if kernel argument
> > +         * is not set and pflash unit 1 is configured.
> > +         */
> > +        if (!kernel_entry) {
> > +            kernel_entry = virt_memmap[VIRT_FLASH].base +
> > +                             virt_memmap[VIRT_FLASH].size / 2;
> > +        }
> > +    }
> > +
> >      /*
> >       * Init fw_cfg.  Must be done before riscv_load_fdt, otherwise the 
> > device
> >       * tree cannot be altered and we get FDT_ERR_NOSPACE.
> > -- 
> > 2.25.1
> > 
> >
> 
> Hi Sunil,
> 
> We should ensure we can use both edk2 and the '-kernel' option. For
> example, guest installation will typically do direct kernel boot,
> and when it's desired / necessary to boot that kernel with ACPI, then
> we'll also need edk2.

Thank you very much, Drew. Let me revise the patch and send.

Thanks
Sunil
> 
> Thanks,
> drew