[ECOS] Redboot "reset" command on iq80321 eval board

[Rick Richardson]

On Fri, Dec 13, 2002 at 01:55:22PM -0500, Mark Salter wrote:
> >>>>> Rick Richardson writes:
> > I then issue the RedBoot "reset" command.  This causes a soft reset by
> > setting a couple of bits in the ATU PCSR, i.e. exactly what a device
> > driver on the host side of the bus would want to do if it wanted to
> > reset a board that had gone out to lunch.
> 
> > The board then goes thru the normal sequence of LED states (scrub
> > loop SL, etc.) until it reaches state "A1".  But this time, the
> > startup message doesn't come out the serial port, and the board
> > cannot be reached via ethernet either.
> 
> > It looks like "something bad" happens at or after the point where
> > vectors.S does the "bl cyg_START".
> 
> Hi Rick,
> 
> I think I know what is happening here, but I'm not sure how to fix
> it. When the 80321 is in a PC, it needs to rely on the PC BIOS to
> setup some BARs on the iop321 processor. RedBoot can then determine
> the address range that can be used for the PCI-X bus that the
> ethernet is on. When you reset the iq80321, but not the PC, RedBoot
> probably uses incorrect addresses to setup the ethernet. You can
> test this theory by disabling the ethernet with S8E1-2 off.
> 
> --Mark

Wow, Mark.  Thanks for the quick, on-the-money reply.  Yep, disabling
the ethernet port via S8E1-2 makes the Redboot "reset" command work.
Understanding the problem is half the battle!

I noticed that the ATU lost its PCI configuration, dunno if that
happened due to a 80321 hardware "feature", or due to Redboot's
initialization.  Once I re-PCI-configed PCI BAR0 to its original BIOS
assigned value, I was also able to "see" the iq80321 from the host
again.

Of course, I want my cake and eat it too, at least for development.
I've been using the ethernet port for GDB access, and the serial
port for console access.  I will have to look into this and see
if the PCI configuration that occurred after hard reset can be
saved and restored during the soft reset.

-Rick

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Rick Richardson  rickr@mn.rr.com        http://home.mn.rr.com/richardsons/
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