Re: About arm32 address translation

[Julien Grall <julien.grall@linaro.org>]

On 10/16/2013 01:02 PM, Chen Baozi wrote:
> 
> On Oct 16, 2013, at 7:44 PM, Chen Baozi <baozich@gmail.com> wrote:
> 
>> On Wed, Oct 16, 2013 at 11:41:18AM +0100, Ian Campbell wrote:
>>> On Wed, 2013-10-16 at 18:26 +0800, Chen Baozi wrote:
>>>> On Wed, Oct 16, 2013 at 11:24:47AM +0100, Ian Campbell wrote:
>>>
>>>>> That suggests that the guest's SP doesn't have a mapping in the guest's
>>>>> PTs. What's the full trace?
>>>>
>>>> See http://pastebin.com/DYL5gkAQ
>>>
>>> Yeah, not a whole lot to go on is there ;-)
>>>
>>> Converting the PC (c02c1544) to a code line with gdb or addr2line would
>>> be a good start I think.
>>>
>>> You could also consider hacking up an earlyprintk via Xen by dropping a
>>> xen_raw_console_write into vprintk_emit once the buffer is formatted and
>>> see if that gets you any useful console output.
>>
>> The hack is workable! See http://pastebin.com/iSGJnKSg
>>
>> It looks like that dom0 has got some issues on "uart3", which is "skipped" due
>> to its disabled status in DT.
> 
> Julien,
> 
> Will the DT node of uart3 be populated to dom0 but not mapped?

If it's the UART used by Xen, the UART is removed from the device tree
and a small UART is emulated by Xen (search arch/arm/vuart.c).

For what I see, Linux is unable to map the memory region (so _mpu_rt_va
= NULL) but he is trying to use it later... It's definitely an error
from Linux side and not Xen.

-- 
Julien Grall