[U-Boot] [PATCH] mpc83xx: Make it boot again

[Joakim Tjernlund]

> From: Liu Dave-R63238 <r63238 at freescale.com>
> To: Andre Schwarz <andre.schwarz at matrix-vision.de>
> Cc: Wood Scott-B07421 <B07421 at freescale.com>, Kumar at theia.denx.de, Tabi Timur-B04825 <B04825 at freescale.com>, Phillips Kim-R1AAHA <R1AAHA at freescale.com>, Gala <galak at kernel.crashing.org>, U-Boot List <u-boot at lists.denx.de>
> Date: 2010/11/15 17:58
> Subject: Re: [U-Boot] [PATCH] mpc83xx: Make it boot again
> Sent by: u-boot-bounces at lists.denx.de
>
> > The experts found an issue within init code and it looks like a proper
> > patch will be added to mainline shortly.
> > The discussion of the proper fix is right in this thread ...
>
> It should be timing issue in the SoC, software did not have a proper
> process to handle
> IMMR registers accessing.
>
> I agree Kumar on this.
> Adding the read back with load is needing for the LAW window changing.
> And something like sync/eieio instruction also need to be added between
> stw and lwz...
> to have a proper order accessing.

After adding some more stuff in start.S I find that a lwz isn't
enough. An extra isync fixes this though

 lwz r4, LBLAWAR1(r3)
 isync

So something is missing but what? I guess isync isn't it either but
it works for now.

 Jocke