Re: [RFC PATCH 4/5] ppc/pegasos2: Use Virtual Open Firmware as firmware replacement

[BALATON Zoltan]

On Tue, 15 Jun 2021, Alexey Kardashevskiy wrote:
> On 6/7/21 01:46, BALATON Zoltan wrote:
> > The pegasos2 board comes with an Open Firmware compliant ROM based on
> > SmartFirmware but it has some changes that are not open source
> > therefore the ROM binary cannot be included in QEMU. Guests running on
> > the board however depend on services provided by the firmware. The
> > Virtual Open Firmware recently added to QEMU imlements a minimal set
> > of these services to allow some guests to boot without the original
> > firmware. This patch adds VOF as the default firmware for pegasos2
> > which allows booting Linux and MorphOS via -kernel option while a ROM
> > image can still be used with -bios for guests that don't run with VOF.
> >
> > Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> > ---
> >   hw/ppc/Kconfig    |   1 +
> >   hw/ppc/pegasos2.c | 622 +++++++++++++++++++++++++++++++++++++++++++++-
> >   2 files changed, 621 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
> > index b895720b28..0eb48128fe 100644
> > --- a/hw/ppc/Kconfig
> > +++ b/hw/ppc/Kconfig
> > @@ -75,6 +75,7 @@ config PEGASOS2
> >       select VT82C686
> >       select IDE_VIA
> >       select SMBUS_EEPROM
> > +    select VOF
> >   # This should come with VT82C686
> >       select ACPI_X86
> >   diff --git a/hw/ppc/pegasos2.c b/hw/ppc/pegasos2.c
> > index 07971175c9..91e5fa8fbe 100644
> > --- a/hw/ppc/pegasos2.c
> > +++ b/hw/ppc/pegasos2.c
[...]
> > +static void add_pci_device(PCIBus *bus, PCIDevice *d, void *opaque)
> > +{
> > +    FDTInfo *fi = opaque;
> > +    GString *node = g_string_new(NULL);
> > +    uint32_t cells[(PCI_NUM_REGIONS + 1) * 5];
> > +    int i, j;
> > +    const char *name = NULL;
> > +    g_autofree const gchar *pn = g_strdup_printf("pci%x,%x",
> > + 
> > pci_get_word(&d->config[PCI_VENDOR_ID]),
> > + 
> > pci_get_word(&d->config[PCI_DEVICE_ID]));
> > +
> > +    for (i = 0; device_map[i].id; i++) {
> > +        if (!strcmp(pn, device_map[i].id)) {
> > +            name = device_map[i].name;
> > +            break;
> > +        }
> > +    }
> > +    g_string_printf(node, "%s/%s@%x", fi->path, (name ?: pn),
> > +                    PCI_SLOT(d->devfn));
> > +    if (PCI_FUNC(d->devfn)) {
> > +        g_string_append_printf(node, ",%x", PCI_FUNC(d->devfn));
> > +    }
> > +
> > +    qemu_fdt_add_subnode(fi->fdt, node->str);
> > +    if (device_map[i].dtf) {
> > +        FDTInfo cfi = { fi->fdt, node->str };
> > +        device_map[i].dtf(bus, d, &cfi);
> > +    }
> > +    cells[0] = cpu_to_be32(d->devfn << 8);
> > +    cells[1] = 0;
> > +    cells[2] = 0;
> > +    cells[3] = 0;
> > +    cells[4] = 0;
> > +    j = 5;
> > +    for (i = 0; i < PCI_NUM_REGIONS; i++) {
> > +        if (!d->io_regions[i].size) {
> > +            continue;
> > +        }
> > +        cells[j] = cpu_to_be32(d->devfn << 8 | (PCI_BASE_ADDRESS_0 + i * 
> > 4));
> > +        if (d->io_regions[i].type & PCI_BASE_ADDRESS_SPACE_IO) {
> > +            cells[j] |= cpu_to_be32(1 << 24);
> > +        } else {
> > +            cells[j] |= cpu_to_be32(2 << 24);
> > +            if (d->io_regions[i].type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
> > +                cells[j] |= cpu_to_be32(4 << 28);
> > +            }
> > +        }
> > +        cells[j + 1] = 0;
> > +        cells[j + 2] = 0;
> > +        cells[j + 3] = cpu_to_be32(d->io_regions[i].size >> 32);
> > +        cells[j + 4] = cpu_to_be32(d->io_regions[i].size);
> > +        j += 5;
> > +    }
>
>
> btw I was wondering if Linux on pegasos2 could assign resources when 
> /chosen/linux,pci-probe-only is in the FDT, could not it? Or the serial 
> device does not probe and Linux does not boot?

Linux probes PCI devices by itself but MorphOS relies on the device tree 
entries so I need at least the reg properties for that then it will map 
the BARs but I think it won't scan the bus otherwise. You still seem to 
add PCI devices in spapr too, at least I think I've got the idea for this 
function above from there.

Regards,
BALATON Zoltan