Re: [tip:x86/doc] x86/doc: mini-howto for using earlyprintk=dbgp

From: Yinghai Lu
Date: Thu Mar 05 2009 - 14:24:29 EST


Daniel Walker wrote:
> On Thu, 2009-03-05 at 10:00 +0000, Yinghai Lu wrote:
>
>> +
>> +Mini-HOWTO for using the earlyprintk=dbgp boot option with a
>> +USB2 Debug port key and a debug cable, on x86 systems.
>> +
>> +You need two computers, the 'USB debug key' special gadget and
>> +and two USB cables, connected like this:
>> +
>> + [host/target] <-------> [USB debug key] <-------> [client/console]
>> +
>> +1. There are three specific hardware requirements:
>> +
>> + a.) Host/target system needs to have USB debug port capability.
>> +
>> + You can check this capability by looking at a 'Debug port' bit in
>> + the lspci -vvv output:
>
> ...
>
>> + c.) Thirdly, you need a second client/console system with a regular USB port.
>
> You might want to combine a.) and c.) since there is some disconnect
> between the two. c.) doesn't explicitly say a second time that the
> client/console needs the debug port capability ..
>
> Or say
>
> a.) You will need two USB ports. One on the client/console system and
> one one the target system.
>
> b.) The client/console and target USB ports must have the debug port
> capability. You can check for this as follows,
>
> c.) ...

thanks for checking it.

can you submit patch to Ingo according to tip/master?

YH
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