Re: JTAG emulator for MPC8548E (v2)

[Eugene Surovegin <ebs@ebshome.net>]

On Wed, Jan 24, 2007 at 12:06:17PM +0100, Laurent Pinchart wrote:
> Hi Eugene,
> 
> > > The new unit works *mostly* fine. No debugging issue (not that I use it
> > > that much anyway, now that the board boots Linux), but still a flash
> > > programming issue. Programming the target parallel NOR flash works in
> > > slow JTAG mode, but not in faster mode using the internal workspace. I
> > > reported the problem several months ago and still haven't received any
> > > solution.
> >
> > Most likely problem isn't in BDI but in your setup. Depending on
> > the particular chip model, to be able use workspace you must have
> > initialized memory first. In fact, I'm pretty sure you haven't
> > configured chip correctly to make workspace usable. I've been using
> > BDI with various PowerPC and MIPS SoCs for many years. It's an excellent
> > tool, you just have to use it correctly.
> 
> I wish it was that simple.

Sorry, but it is. It's a low level tool which requires deep knowledge 
of the chip.

>  It is probably a target processor configuration 
> issue, as I can use the workspace if
> 
> a) the target flash has already been programmed with U-Boot
> b) the BDI-2000 is misconfigured and fails to stop the target processor at 
> startup.
> 
> I can thus use the workspace when U-Boot initializes the processor.

Wow, so you knew it wasn't BDI but a configuration problem from the 
start. So it all was just a FUD, how low.  

> 
> I had a look at U-Boot code and tried to initialize the processor registers 
> with the same values, without luck. I asked Abatron's French distributor for 
> technical support, and they haven't been able to help me. They made me try 
> lots of different initialization sequences. Several people online sent me 
> their configuration file, and none of them worked for me.
> 
> So, there must be a configuration problem somewhere, but even Abatron's 
> technical support haven't been able to find it. That's why I complained about 
> their support in my e-mail.

In your original e-mail you made it look like BDI has a bug in it, 
which in fact isn't true. Bad support might be a concern, I agree, but 
this doesn't make a tool bad, IMHO.

-- 
Eugene