[U-Boot] Booting from NAND on MX51

[Stefano Babic]

Andreas Orfanos wrote:
> Hi,
> 

Hi Andreas,

> I am using mx51 3stack Freescale dev board, and I would like to make it
> boot u-boot from NAND.

I sent patches for the mx51evk (babbage board), but NAND is not (yet)
supported. This is the first MX51 board that should go into mainline.
The mx51_3stack is not supported in u-boot. How do you derive your
u-boot ? From my patches or from another source ?

> Does anyone have any local changes that enable that feature?
> 
> The u-boot works when is downloaded into RAM from Jtag, but can't get it
> boot from NAND when I write it there. 
> Do I have to develop nand_spl, early stage0 loader?

Well, I think the MX51 can boot without an early loader. The processor
can boot directly from NAND, if the correct boot pins are set and no
internal fuses are blown to avoid it, as stated in the user manual. The
processor reads an image in the IMX format - you see documentation in
doc/README.imximage. At the beginning of the image there must be a
suitable for your board DCD table, that enables the IOMUX for the NAND
controller and does the required setup. The image length is part of the
IMX header and the processor copies automatically from NAND to the RAM
address you set in the header and then jumps to the starting address.

As I said, I have not tried (the mx51evk has no NAND). However, booting
from other sources (SD card, SPI Flash) works in this way.

Regards,
Stefano

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