[U-Boot] Flashing u-boot on NAND flash

[Stefan Roese <sr@denx.de>]

On Tuesday 20 January 2009, Afzal Nadirshah wrote:
>        I am new to board bring up and I have a few queries.
>        We have a custom board with a PPC 460EX processor and a NAND flash.
> We are using a BDI 3000 JTAG debug interface. My problem is how to load the
> u-boot onto the NAND flash on the fresh board, since the BDI does not
> support writing into NAND flash.

Correct. AFAIK, the BDI doesn't support direct NAND reading/writing.

> Also from the mailing lists I understand 
> that it is difficult to execute the u-boot by directly downloading to the
> RAM and executing it.
>        Please guide me on how to approach this.

This is indeed not so easy. Currently there is no 4xx U-Boot target option to 
configure the image to boot directly from already configured SDRAM as until 
now all 4xx boards were able to boot from NOR FLASH. When only NAND booting 
is supported as in your case, you probably need such an configuration option 
such as CONFIG_SKIP_LOWLEVEL_INIT which is available on other platforms 
(MIPS, ARM).

Best regards,
Stefan

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