[U-Boot-Users] Booting from NAND Flash Problems

Wolfgang Denk wd at denx.de
Mon May 22 11:38:00 CEST 2006

In message <4501134.post at talk.nabble.com> you wrote:
> I then create a board and implement the usual functions checkboard,
> initdram, low_level_init etc....
> I then use an MTD driver that runs perfectly under linux.  i.e the same C

Why don't you use the existing NAND flash code in U-boot?

Please note that "runs perfectly under linux" doesn't  mean  anything
here. U-Boot is not Linux.

> It loads the environment but always rejects it based on the CRC check.  
> If I cache flush after reading the environment from flash the CRC check
> completes ok and it uses this environment.

You probably should make sure to use  proper  cache  policies  and/or
flushing troughout your port.

> problem is all the code that follows (device init, eth_initialise, etc fail)
> Without a cache flush these work.

That's what I said: fix your port of U-Boot.

> I think that you need to initialise the NAND flash and env_relocate before
> the calls to eth_initialise etc so I do not feel my order is incorrect.

Why don't you just use the existing code?

You mention "our driver", "my code" and "my order" -  how  should  we
comment  on  this?  If you think you know beter and come up with your
own implementation then you will have to debug it yourself. All I can
say is that the exsiting code in U-Boot works fine  on  a  couple  of

> So I was wondering what ideas people may have.  I feel that the most likely
> is that my linux MTD driver use GFP_DMA flag and kmalloc when it is used in
> Linux.  This may (I am still investigating) result in it using a different

Dump your custome code. Use the existing one.

This is my last comment on this.

> >Define "run uncached".
> Caches disabled.

Instruction cache or data cache or both or what? Yo need to  be  more

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
I perceive a possibility of an immediate  chronological  sequence  of
events which includes a violence.
                        - Terry Pratchett, _The Dark Side of the Sun_

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