Re: [Qemu-devel] [PATCHv3 1/2] sun4m: Add Sun CG3 framebuffer and corresponding OpenBIOS FCode ROM

[Mark Cave-Ayland]

On 19/02/14 13:35, Leandro Dorileo wrote:

Hi Leandro,

> > +static void cg3_realizefn(DeviceState *dev, Error **errp)
> > +{
> > +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> > +    CG3State *s = CG3(dev);
> > +    int ret;
> > +    char *fcode_filename;
> > +
> > +    /* FCode ROM */
> > +    memory_region_init_ram(&s->rom, NULL, "cg3.prom", FCODE_MAX_ROM_SIZE);
> > +    vmstate_register_ram_global(&s->rom);
> > +    memory_region_set_readonly(&s->rom, true);
> > +    sysbus_init_mmio(sbd,&s->rom);
> > +
>
>
> I think this initialization code could be done in a SysBusDeviceClass init 
> operation,
> don't you think?

I think it's possible since these MemoryRegions don't depend upon 
properties, but I leave that to Andres who seems reasonably happy with 
the patchset in its current form.

> > +    fcode_filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, CG3_ROM_FILE);
> > +    if (fcode_filename) {
> > +        ret = load_image_targphys(fcode_filename, s->prom_addr,
> > +                                  FCODE_MAX_ROM_SIZE);
> > +        if (ret<  0 || ret>  FCODE_MAX_ROM_SIZE) {
> > +            error_report("cg3: could not load prom '%s'", CG3_ROM_FILE);
>
>
> What happens if we fail to load the rom file? is the framebuffer supposed to 
> work?

I guess the framebuffer would still "work" although nothing would be 
able to find its address because the node wouldn't exist in the device tree?


ATB,

Mark.