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

[Jiaxun Yang <jiaxun.yang@flygoat.com>]

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);
>>