Re: [Qemu-ppc] qemu-system-ppc64 -M ppce500 always booting to qemu monitor console plus no output on serial console

[Do Vincenzo]

On 17.12.15 16:39, Alexander Graf wrote:
>On 17.12.15 14:14, Do Vincenzo wrote:
>> On Thu, 17 Dec 2015, BALATON Zoltan wrote:
>>> On Thu, 17 Dec 2015, Do Vincenzo wrote:
>>>> Ok, so the last IN occurrence is this one: 0x000000000001fad8:  b       
>>>> 0x1fad8
>>>> here's the full log of the last two IN: http://paste.ubuntu.com/14072313/
>>>> after that, the log keeps going on but without any IN.
>>>
>>> It is jumping to itself so it reached a halt condition.
>>>
>>>> Also I've tried to print what's at the 0x1fad8 address but the output is 
>>>> empty.
>>>> I've printed the log buffer with the -cpu parameter: 
>>>> http://paste.ubuntu.com/14072246/
>>>
>>> I see a kernel panic in this referring to the device tree:
>>>
>>> BUG: Failed verifying flat device tree, bad version?
>>> What that means though I have no idea but you could try searching for
>>> this.
>>>
>>> Regards,
>>> BALATON Zoltan
>>
>> Thank you for your reply.
>>
>> The error seems to come from the "/arch/powerpc/kernel/prom.c" file at line 
>> 650.
>>
>> From this patch: 
>> https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/120444.html
>> I can guess that the version of the dtb used for the guest is too old. So 
>> which dtb should I use?
>> I tried using the mpc8544ds.dtb compiled from a 4.x mainline linux but I get 
>> the same error.
>>
>> And also, shouldn't I be able to see this error on the console? Why it 
>> doesn't get printed there?
>
> That one's easy - the fdt is used to tell Linux where to print
> something. So without working device tree parsing, you don't see output,
> because Linux doesn't know where the serial console lives.

Of course! I should have figured it out by myself....

> As to why it doesn't like the fdt we generate inside QEMU, I don't know.
> Do you manage to get into U-Boot when you run QEMU without -kernel?
> Also, please give 2.5.0 a shot - compile it with its built-in device
> tree code (git submodule update --init dtc).

Yes I manage to get into U-Boot.

> To at least sanity check that *something* works at all :), please try
> and grab a known-working uImage from
> http://csgraf.de/tmp/e5500-bug/uImage. Then run it using
>
> qemu-system-ppc64 -M ppce500 -nographic -cpu e5500 -kernel uImage
>
> Alex

I tested your uImage and it works both on my laptop and on the Freescale board! 
So I guess I'm doing something wrong when generating mine. Could you please
share how did you generate yours? 

Regards,
Vincenzo Do