RE: 4430SDP boot failure - solved + SPI bug fix

Santosh Shilimkar
2011-01-07T19:05:41Z

> -----Original Message-----
> From: Russell King - ARM Linux [mailto:linux@arm.linux.org.uk]
> Sent: Saturday, January 08, 2011 12:23 AM
> To: Santosh Shilimkar
> Cc: linux-omap@vger.kernel.org; Tony Lindgren
> Subject: Re: 4430SDP boot failure - solved + SPI bug fix
>
> On Fri, Jan 07, 2011 at 11:55:10PM +0530, Santosh Shilimkar wrote:
> > > And, with one ARM errata disabled, the kernel finally boots. So
> the
> > > "X-Loader hangs" message means that we did something that non-
> secure
> > > mode prevented us from doing.
> > >
> > Actually it's not. The error message is quite misleading.
> Basically in
> > x-loader exception handlers are setup and all these handlers
> report
> > same message ("X-Loader hangs"). This should be fixed so that it
> can
> > report more meaningful info like data abort, prefetch abort etc.
> >
> > Till the vector relocation in the kernel exceptions are not set up
> > so code jumps to already installed exceptions in the x-loader and
> > hence the messege.
>
> I disagree with your "actually it's not". It was errata 742230,
> which
> requires access to the CP15, c15, c0, 1 register (a diagnostic
> register)
> which I bet provokes an undefined instruction trap from non-secure
> mode.
>
742230 errata workaround is not implemented in the x-loader so I
can surely say it's not the secure violation.

He is the x-loader source tree.
http://dev.omapzoom.org/?p=bootloader/x-loader.git;a=shortlog;h=refs/heads
/omap4_dev

Even simple things like if DDR is not configured correctly or not
Stable, code/data access takes abort which lands up in the "X-loader
hang messege"

> Hence, the reason it vectored to the X-loader was because we tried
> to
> do something in the non-secure mode which we're prevented from
> doing.
My suspect was clock configurations on the older boot loaders were
Incomplete that might have lead to issue since now more drivers are
getting enabled in newer kernels.