[U-Boot] [RFC] Make U-Boot log great again

[Bin Meng]

Hello,

On Fri, Mar 23, 2018 at 1:44 PM, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi,
>
> On Sat, Feb 17, 2018 at 3:49 AM, Robert Nelson <robertcnelson at gmail.com> wrote:
>> On Fri, Feb 16, 2018 at 1:01 PM, Sam Protsenko
>> <semen.protsenko at linaro.org> wrote:
>>> Hi guys,
>>>
>>> TL;DR This is a suggestion about fixing U-Boot log, which has got
>>> worse recently.
>>>
>>> Right now U-Boot and SPL logs are cluttered with bogus warnings like
>>> these (on X15 board, but I'm pretty sure it should appear on many
>>> others):
>>>
>>>     Loading Environment from FAT...
>>>     *** Warning - bad CRC, using default environment
>>>     Failed (-5)
>>
>
> Do we plan to fix this "Failed (-5)" message? It's very confusing.
> Like previous U-Boot just printing "*** Warning - bad CRC, using
> default environment" is enough I think.
>

The v2018.07 release still has this "Failed (-5)" message on boot.
When do we plan to fix this?

>> This one seems to cause the most confusion with end users.  They like
>> to think it's a real bug, when in reality, "saveenv" and friends was
>> just never run from within u-boot or a separate environment partition
>> wasn't pre-programmed.
>>
>> It's one of those bugs, users asked 10 years ago when the Beagle first
>> launched, yet users still ask from time to time..
>>
>>>
>>> Those are the consequences of next commit:
>>>
>>>     fb69464eae1e ("env: Allow to build multiple environments in Kconfig")
>>>
>>> Because of this commit, I can see following changes in my .config file:
>>>
>>>     +CONFIG_ENV_IS_IN_FAT=y
>>>     +CONFIG_ENV_FAT_INTERFACE="mmc"
>>>     +CONFIG_ENV_FAT_DEVICE_AND_PART="0:1"
>>>     +CONFIG_ENV_FAT_FILE="uboot.env"
>>>
>>> which led U-Boot to try and load the environment from different
>>> sources. I agree that it's good thing to do and can be useful, but the
>>> problem is that the code for loading the environment wasn't changed to
>>> handle errors properly.
>>>
>>> How I suggest to handle that case:
>>>
>>>  1. If we have two sources for the environment (e.g. FAT partition on
>>> SD card and some raw partition on eMMC), we shouldn't print error
>>> messages if we were unable to load the environment from one source
>>>  2. We should probably print some human-readable information that we
>>> didn't find the environment there, let's skip and look for next source
>>> (but don't print those warnings/failed messages)
>>>  3. And only print the error message in case when U-Boot environment
>>> wasn't found at all (on all possible sources).
>>>
>>> I don't have enough time to fix this by my own right now. But let's
>>> discuss how to approach this issue in a best way possible. And if
>>> someone wants to step forward and do that -- would be really nice. If
>>> no -- I can look into that later. But let's collect some opinions
>>> here, first.
>>
>> I've also found, when you are dealing with multiple sources, it's nice
>> to print "where" you came from.
>>
>> Otherwise, I've been known to make things way to verbose, but it's
>> easier to debug years later, when your adding a new family, or
>> overhauling when/how "overlays" are handled...
>>

Regards,
Bin