[U-Boot] [PATCH 03/13] apalis/colibri_t20/t30: integrate recovery mode detection

Stephen Warren swarren at wwwdotorg.org
Thu Jul 9 17:51:34 CEST 2015


On 07/09/2015 09:02 AM, Stefan Agner wrote:
> On 08.07.2015 22:57, Stephen Warren wrote:
>> On 07/07/2015 12:04 AM, Marcel Ziswiler wrote:
>>>
>>>
>>> On 6 July 2015 18:38:21 CEST, Simon Glass <sjg at chromium.org> wrote:
>>>
>>>> Out of interest, is this just a message for the user? Why is it useful?
>>>
>>> Well, we or customers might do other interesting things on entering
>>> rcm like stopping autoboot or automatically start ums.
>>
>> But that's not what this patch does; it simply prints a message. It
>> doesn't seem terribly useful.
>>
> IMO, it really is useful: The boot ROM takes other initialization steps
> when using RCM recovery mode vs. full NAND/eMMC boot. We have had issues
> in the past where the Linux kernel hangs or shows issues just because
> something (e.g. USB, NAND or eMMC) was/or was not initialized by the
> boot ROM first. Of course those are bugs, and need to be resolved in the
> end. But it can be helpful to reproduce issues when one sees whether the
> recovery mode has been used or not...

Surely you can remember whether you pressed the reset button or used 
tegrarcm/... to push U-Boot onto the device in recovery mode?

If it really is that useful, then I'd suggest not making this 
board-specific, since it's a SoC-defined concept, not a board-defined 
concept.


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