Re: [PATCH v3 3/3] hw/mips/boston: Add FDT generator

[Jiaxun Yang]

在 2021/10/3 18:45, Philippe Mathieu-Daudé 写道:
> On 10/2/21 20:45, Jiaxun Yang wrote:
> > Generate FDT on our own if no dtb argument supplied.
> > Avoid introducing unused device in FDT with user supplied dtb.
> >
> > Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> > --
> > v2: Address f4bug cmments (Thanks!)
> > ---
> >   hw/mips/boston.c | 234 +++++++++++++++++++++++++++++++++++++++++++++--
> >   1 file changed, 226 insertions(+), 8 deletions(-)
> >   static void boston_mach_init(MachineState *machine)
> >   {
> >       DeviceState *dev;
> > @@ -555,21 +771,23 @@ static void boston_mach_init(MachineState *machine)
> >                              NULL, 0, EM_MIPS, 1, 0);
> >   
> >           if (kernel_size) {
> > +            int dt_size;
> > +            g_autofree const void *dtb_file_data, *dtb_load_data;
> >               hwaddr dtb_paddr = QEMU_ALIGN_UP(kernel_high, 64 * KiB);
> >               hwaddr dtb_vaddr = cpu_mips_phys_to_kseg0(NULL, dtb_paddr);
> >   
> >               s->kernel_entry = kernel_entry;
> >               if (machine->dtb) {
> > -                int dt_size;
> > -                g_autofree const void *dtb_file_data, *dtb_load_data;
> > -
> >                   dtb_file_data = load_device_tree(machine->dtb, &dt_size);
> > -                dtb_load_data = boston_fdt_filter(s, dtb_file_data, NULL, 
> > &dtb_vaddr);
> Isn't it better to let boston_fdt_filter() here, ...
>
> > -
> > -                /* Calculate real fdt size after filter */
> > -                dt_size = fdt_totalsize(dtb_load_data);
> > -                rom_add_blob_fixed("dtb", dtb_load_data, dt_size, dtb_paddr);
> > +            } else {
> > +                dtb_file_data = create_fdt(s, boston_memmap, &dt_size);
> ... and pass kernel_cmdline & machine->ram_size to create_fdt(),
> filling the bootargs & memory nodes?
That will be done in boston_fdt_filter, which shares between FDT 
generator path
and dtb file path.

Thanks.
- Jiaxun
> >               }
> > +
> > +            dtb_load_data = boston_fdt_filter(s, dtb_file_data, NULL, 
> > &dtb_vaddr);
> > +
> > +            /* Calculate real fdt size after filter */
> > +            dt_size = fdt_totalsize(dtb_load_data);
> > +            rom_add_blob_fixed("dtb", dtb_load_data, dt_size, dtb_paddr);
> >           } else {
> >               /* Try to load file as FIT */
> >               fit_err = load_fit(&boston_fit_loader, machine->kernel_filename, 
> > s);