Re: [PATCH] xen/arm64: Make sure we get all debug output

[Dirk Behme <dirk.behme@gmx.de>]

On 04.02.2016 18:07, Dirk Behme wrote:
> On 04.02.2016 18:00, Ian Campbell wrote:
>> On Thu, 2016-02-04 at 17:49 +0100, Dirk Behme wrote:
>>> From: Dirk Behme <dirk.behme@de.bosch.com>
>>>
>>> Starting in the wrong ELx mode I get the following debug output:
>>>
>>> ...
>>> - Current EL 00000004 -
>>> - Xen must be entered in NS EL2 mode -
>>> - Boot failed -
>>>
>>> The output of "Please update the bootloader" is missing here.
>>>
>>> Make sure this is output, too. With this, we get
>>>
>>> ...
>>> - Current EL 00000004 -
>>> - Xen must be entered in NS EL2 mode -
>>> - Please update the bootloader -
>>> - Boot failed -
>>>
>>> as intended.
>>
>> Ah, this is because gas does not concatenate strings in the same way
>> as C,
>> i.e. in C:
>>     "A" "B" "C"
>>
>> becomes 'A', 'B', 'C', '\0'
>>
>> while in gas it becomes 'A', '\0', 'B', '\0', 'C', '\0'
>>
>> I'd like to modify the "...is missing here" above to go a bit further:
>>
>>      ...is missing here, because string concatenation in gas, unlike
>> in C,
>>      keeps the \0 between each individual string.
>>
>> Would that be OK with you? (I can do it on commit if you are happy
>> with it)
>
>
> Sure, fine with me :)


Could this be applied, then?

Best regards

Dirk


>>>
>>> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
>>> ---
>>>   xen/arch/arm/arm64/head.S |    4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
>>> index 9ed9a93..19fa2bb 100644
>>> --- a/xen/arch/arm/arm64/head.S
>>> +++ b/xen/arch/arm/arm64/head.S
>>> @@ -309,8 +309,8 @@ common_start:
>>>           b.eq  el2 /* Yes */
>>>
>>>           /* OK, we're boned. */
>>> -        PRINT("- Xen must be entered in NS EL2 mode -\r\n" \
>>> -              "- Please update the bootloader -\r\n")
>>> +        PRINT("- Xen must be entered in NS EL2 mode -\r\n")
>>> +        PRINT("- Please update the bootloader -\r\n")
>>>           b fail
>>>
>>>   el2:    PRINT("- Xen starting at EL2 -\r\n")
>>
>