Hi Wolfgang, Heinrich, Heiko,

On 20/03/2020 09:08, Wolfgang Denk wrote:
Dear Heinrich,

In message<a1b7a877-e950-b09a-a0f6-2c9c9cb7e...@gmx.de>  you wrote:
To me this sounds very much like what you are adding here (plus a
few features more).  Does it make sense to unify such code?
It seems you are relating to
https://lore.kernel.org/lkml/844oyrqvvb....@sauna.l.org/t/
No, I'm not.  I was talking of my own code from many, many years
ago.

ramoops in Linux is exactly doing what was suggested in 2009. You can
find the Documentation/admin-guide/ramoops.rst
We had this in U-Boot long before that time.  It was a key
requirement when we added POST support in 2002.

git grep -GHrn 'shared log' finds nothing in U-Boot. So if any part of
the old implementation in U-Boot exists, could you, please, point us to
the coding.
The shared log buffer support was added by commit 56f94be3ef63:

commit 56f94be3ef63732384063e110277ed89701b6471 (tag: LABEL_2002_11_05_1735)
Author: Wolfgang Denk <wdenk>
Date:   Tue Nov 5 16:35:14 2002 +0000

     * Add support for log buffer which can be passed to Linux kernel's
       syslog mechanism; used especially for POST results.

     * Patch by Klaus Heydeck, 31 Oct 2002:
       Add initial support for kup4k board

The code was mainly in common/cmd_log.c, but this got heahily
rewritten and is now in cmd/log.c ; apparently this got lost (like
the original copyright, sic!) when Simon modified / rewrote this
driver.

For history, try: git log --follow -- common/cmd_log.c


If the original design never made it into Linux and there is an
established Linux interface since 2011, I would plead to eliminate any
remaining non-compliant coding from U-Boot should it exist.
I understand what Linus has is one-way, only focussing on crash
dump, i. e. it does not allow to pass information from U-Boot to Linux?

Yes, currently it is not possible to pass information from U-Boot to Linux.
But, PStore does not only store crash dump, but also console, ftrace and user space logs.

It may be possible to add a "bootloader" storage space to PStore.

Best regards,

Frédéric Danis

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