Re: Netra T5220

[Don NetBSD <netbsd-embedded%gmx.com@localhost>]

On 11/19/2018 2:21 PM, Brett Lymn wrote:
> On Sun, Nov 18, 2018 at 03:57:53PM -0700, Don NetBSD wrote:
> > Think of it as having a similar function wrt the ILOM as the OBP has to
> > the OS in older Sun boxen.
>
> No, this is a totally different processor, the SP is, effectively, a
> separate computer that has hooks into the main machine's hardware for
> monitoring and control.  Changing things at the u-boot level has no real
> effect on the main machine, just the SP.  You can still access the OBP
> when you start the host console.

That's not what I said.  I made the analogy that u-boot is to the SP
as OBP is to SunOS (on an "older", no-SP box).

I.e., if you look at the SP as a product in itself, u-boot is the
preboot environment -- in much the same way that OBP provides a
"preboot environment" for Solaris.

> > Of course, at $WORK, you're not trying to get INTO a box that someone
> > has locked up -- as YOU are the party who likely locked it up in the first
> > place!
>
> Indeed, what I really meant is that I have never seen any official
> Oracle documentation for the SP boot.  It is not something that they
> encourage you to poke at.

Actually, they do!  Just not for THIS product!  I've been grep-ing
documentation for other (Sun) products with SP equivalents and
taking my cue from what I find, there, to decide what to poke at,
here.

> > OTOH, when a system falls into your lap, you don't always have that sort
> > of access.  So, you need to rely on mechanisms that the designers put in
> > place to make this sort of thing possible!
>
> Yes, it sounds like a lot of it is aimed at disaster recovery, when the
> machine has cratered.  At $WORK that usually means somebody's services
> are down which they normally get agitated about at which point we
> usually just either have an Oracle field engineer out or have support
> guiding us.

With rescued kit, I don't have the luxury (or expense!) of a support contract.
So, the more I can learn about a box, on my own, the better off I will be in
the longrun.

I create elaborate sets of notes for the stuff that I uncover/discover as
it will likely be "a long time" before I find myself staring at the
same box in some degraded capacity (I don't trust my meatware to hold onto
all of those sorts of details)