[Skiboot] [RFC PATCH 10/10] console: add log scraping OPAL call

[Stewart Smith]

Oliver O'Halloran <oohall at gmail.com> writes:
> Adds an OPAL call that parses the OPAL log, finds important messages
> (log_level below PR_WARN) and copies them up to the OS. This is intended
> to make firmware error messages more visible to system administrators
> since it allows the OS the report them in the usual places rather than
> a OPAL specific log file (e.g. /sys/firmware/opal/msglog under linux).
>
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>


So, I've had a renewed bit of thinking on what we should do here, and
something we could do without too much effort to make a decent
(and progressive) improvement(s) to getting messages out to users.

I'm thinking that to start with, we may want 2-3 additional bits of info
being passed to linux:
1) is this a message from current boot or previous
   The logic being that we may be able to go "and here's why you died"
   on subsequent boot?
   (I'm not sure on this...)
2) arbitrary other bit of info (extendable). i.e. we could point to the
   phandle of the thing that died, the error log id (or some
   replacement), but the idea being we've set up the call from day 1 to
   support that.
3) Current versus earlier in boot?

Additionally, we should be clear that post-kexec, we get everything again.

-- 
Stewart Smith
OPAL Architect, IBM.