Re: [PATCH 2/2] hw/riscv: Support different address-cells for initrd

[Conor Dooley <conor@kernel.org>]

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On Mon, Oct 21, 2024 at 04:30:11PM -0300, Daniel Henrique Barboza wrote:
> 
> 
> On 10/21/24 1:09 AM, Jim Shu wrote:
> > The cells of 'initrd-start/end' should follow the '#address-cell'.
> > QEMU API could support 1 and 2 cells.
> > 
> > Signed-off-by: Jim Shu <jim.shu@sifive.com>
> > ---
> >   hw/riscv/boot.c | 14 ++++++++++++--
> >   1 file changed, 12 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
> > index ad45bd7a6a..76b099c696 100644
> > --- a/hw/riscv/boot.c
> > +++ b/hw/riscv/boot.c
> > @@ -182,6 +182,7 @@ static void riscv_load_initrd(MachineState *machine, uint64_t kernel_entry)
> >       void *fdt = machine->fdt;
> >       hwaddr start, end;
> >       ssize_t size;
> > +    uint32_t acells;
> >       g_assert(filename != NULL);
> > @@ -209,9 +210,18 @@ static void riscv_load_initrd(MachineState *machine, uint64_t kernel_entry)
> >       /* Some RISC-V machines (e.g. opentitan) don't have a fdt. */
> >       if (fdt) {
> > +        acells = qemu_fdt_getprop_cell(fdt, "/", "#address-cells",
> > +                                       NULL, NULL);
> > +        if (acells == 0) {
> > +            error_report("dtb file invalid (#address-cells 0)");
> > +            exit(1);
> > +        }
> > +
> >           end = start + size;
> > -        qemu_fdt_setprop_u64(fdt, "/chosen", "linux,initrd-start", start);
> > -        qemu_fdt_setprop_u64(fdt, "/chosen", "linux,initrd-end", end);
> > +        qemu_fdt_setprop_sized_cells(fdt, "/chosen", "linux,initrd-start",
> > +                                     acells, start);
> > +        qemu_fdt_setprop_sized_cells(fdt, "/chosen", "linux,initrd-end",
> > +                                     acells, end);
> >       }
> 
> Is this a legal format for linux,initrd-start and linux,initrd-end?
> 
> This link:
> 
> https://www.kernel.org/doc/Documentation/devicetree/bindings/chosen.txt
> 
> Defines both attributes as:
> 
> "These properties hold the physical start and end address of an initrd that's
> loaded by the bootloader."
> 
> So I'm not sure if this format you're using here is valid.

Looks like my input isn't really required here anymore, but I think
these two are actually identical in how they appear in the blob. Don't
see much reason to change it.

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