[PATCH v4 1/4] imx9: Add support for saving DDR training data to NVM

[Francesco Dolcini]

Hello Simona,

On Tue, Jun 02, 2026 at 01:59:39PM +0300, Simona Toaca wrote:
> On Thu, May 28, 2026 at 10:55:23AM +0530, Kumar, Udit wrote:
> > On 4/30/2026 2:03 PM, Simona Toaca (OSS) wrote:
> > > From: Simona Toaca <simona.toaca at nxp.com>
> > > 
> > > DDR training data can be saved to NVM and be available
> > > to OEI at boot time, which will trigger QuickBoot flow.
> > > 
> > > U-Boot only checks for data integrity (CRC32), while
> > > OEI is in charge of authentication when it tries to
> > > load the data from NVM.
> > > 
> > >  
> [...]
> > > +#define DDRPHY_QB_PSTATES	0
> > > +#define DDRPHY_QB_PST_SIZE	(DDRPHY_QB_PSTATES * 4 * 1024)
> > 
> > [..]
> > Sorry for basic question, in case OEI layer changes format due to one of
> > other reason then how you are making sure, struct ddrphy_qb_state is
> > aligned
> > 
> > + * This structure needs to be aligned with the one in OEI.
> > 
> For now, the structure is stable. If anything changes, I will take care
> to update U-Boot accordingly.

Did you consider Emanuele's email in which he thinks that what we have today
should already be changed? 

And how do you handle a mix of U-Boot vs OEI version? How can you ensure
that those are compatible? To me this is a mess. You are building an ABI
between U-Boot and the OEI.

Francesco