[PATCH 0/5] collected fallout of porting an ATSAMA5D27 based board

[Alexander Dahl]

Hello Benedikt,

Am Fri, Oct 18, 2024 at 04:19:08PM +0200 schrieb Benedikt Spranger:
> On Fri, 18 Oct 2024 15:11:20 +0200
> Alexander Dahl <ada at thorsis.com> wrote:
> 
> Hello Alexander,
> 
> > Am Fri, Oct 18, 2024 at 10:30:00AM +0200 schrieb Benedikt Spranger:
> > > OK, you might say the nand_atmel NAND driver is obsolete, but it
> > > was the only solution to get booting from NAND running. The new DM
> > > based NAND driver refused to do anything usefull, so I dropped it
> > > after spending a couple of days debugging it:
> > 
> > Strange.  I have at least three different boards with SAMA5D27
> > successfully booting from NAND flash with the new DM based driver
> > (unfortunately none of them upstreamed, which also won't change in the
> > foreseeable future, sorry).
> OK.
>  
> > Do you use at91bootstrap as 2nd level bootloader like me or something
> > else?
> I use the U-Boot SPL. There is no UBI support in at91boostrap. There
> were some attemps, but...
> No interest at the at91bootstrap side.

Yeah, been there.  Wanted at91bootstrap to boot from SPI-NOR which is
_not_ Quad-SPI, and the feature request was closed with "if you wanna
do it by yourself, ask our support for help". :-/

> > For me it was basically getting the dts for U-Boot correct, but
> > I got that running with all U-Boot releases since 2023.04 up to
> > 2024.10.  Could you share some more detail?
> I face all the trouble in SPL. And since the SPL is the essential part
> here (UBI support) I gave up at one point. I simply couldn't any
> usefull read data from the NAND flash, but all 0.

You can not store bootstrap or SPL in UBI, it must sit in first sector
of raw NAND, I suppose that's how you load SPL?  Did you try
reading/writing raw NAND from there?  I'm not familiar with SPL, does
it consider dts?  I could share my dts parts if that helps you.

(What I do here: SoC loads at91bootstrap from raw NAND at offset 0,
at91bootstrap loads U-Boot from raw NAND at some offset like 0x20000,
U-Boot (proper) loads everything else from UBI.)

Greets
Alex