[U-Boot] [PATCH 00/13] log: Add a new logging feature

[Wolfgang Denk]

Dear Simon,

sorry for jumping in so late...

In message <20170916212331.170463-1-sjg at chromium.org> you wrote:
>
> At present U-Boot has a logbuffer feature which records output in a memory
> buffer for later display or storage. This is useful but is not at present
> enabled for any board.

Background explanation:  When this was implemented, the buffer
handling was fully compatible with the Linux kernel logbuffer.
And U-Boot was able to reserve memory (at the top of the RAM) that
could be shared between U-Boot and Linux, so you could for example 
write U-Boot POST results into the log buffer, and read it using
standard syslog tools in Linux.  Or keep the panic messages of the
previous crash and read it after reboot.

IIRC this was in production use only on Power architectre systems,
and it broke (and nover got fixed) when the Linux log buffer was
reworked.

> This series introduced a new logging system which supports:
> - various log levels from panic to debug
> - log categories including all uclasses and a few others
> - log drivers to which all log records can be sent
> - log filters which control which log records make it to which drivers

You don't mention it here, but would it be possible to keep
compatibility with the Linux logbuffer implementation in mind?

So we could re-implement this shared logbuffer thingy in case
someone finds it useful?

Thanks!

Best regards,

Wolfgang Denk

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