Re: [Qemu-devel] [PATCH] hw/misc/blob-loader: add a generic blob loader

[Peter Crosthwaite]

On Mon, Jan 6, 2014 at 2:22 PM, Li Guang <address@hidden> wrote:
> Peter Crosthwaite wrote:
>>
>> On Mon, Jan 6, 2014 at 1:55 PM, Li Guang<address@hidden>  wrote:
>>
>>>
>>> Li Guang wrote:
>>>
>>>>
>>>> Paolo Bonzini wrote:
>>>>
>>>>>
>>>>> Il 02/01/2014 11:51, Peter Crosthwaite ha scritto:
>>>>>
>>>>>>>>
>>>>>>>> No, please use "realize" and avoid init.  This way you can use an
>>>>>>>> Error*
>>>>>>>> to report the error.
>>>>>>>>
>>>>>>>> Also, the actual load_image_targphys call probably should be done in
>>>>>>>> a
>>>>>>>> reset handler, not at realize time.
>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>> Ok I think that settles it. The actual blobbing needs to happen at
>>>>>> reset time. Perhaps the correct approach is to do as much as possible
>>>>>> (file-path / address sanitsation etc) at realize time, then only the
>>>>>> actual blob load happens at reset. Going on what Paolo said, I think
>>>>>> for this device ::init is actually a nop.
>>>>>>
>>>>>
>>>>> Yeah, also because init is in fact a legacy interface to realize.
>>>>>
>>>>> Paolo
>>>>>
>>>>>
>>>>
>>>> Ok, thanks!
>>>>
>>>>
>>>>
>>>
>>> Sorry, seems load blob at reset handler can't do the right job,
>>> while the same action can play very well at init or realize.
>>>
>>
>> What's the exact problem with the reset idea?
>>
>>
>>
>
> code snippet:
> static void blob_loader_reset(DeviceState *dev)
> {
>     BlobLoaderState *s = BLOB_LOADER(dev);
>
>     if (load_image_targphys(s->file, s->hwaddr, MAX_BLOB_SIZE) < 0) {
>         error_report("can't load %s\n", s->file);
>         exit(1);
>     }
> }
>
> if it is device reset handler, no result,
> kernel doesn't find and parse blob,
> if it is called at device realize phase,
> it works.
>

Need to figure out why I think. There's no fundamental problem here
AFAIK. It must be a bug somewhere.

> Thanks!
>
>
>>> any suggestion to figure out this problem?

Run QEMU in GDB and break on your new reset function to see if it is
ever called. If not have a look into QOM/qdev to see how resets work
and how that plays with -device args. If yes, have a look into
load_image_targphys and see why that's not working.

Regards,
Peter

>>>
>>> Thanks!
>>>
>>>
>>>
>>>
>>
>>
>>
>
>
>