[U-Boot-Users] Re: Patch s3c2410 nand-boot.

[Gianluca]

Wolfgang Denk wrote:
> Dear Gianluca,
> 
> in message <3F68D1DF.7020007 at libero.it> you wrote:
> 
>>I send you my patch for s3c2410 ARM processor. This patch implements 
>>boot directly from nandflash. I haven't created new board in board 
>>directory but I have writed new config-file (smdk2410nand.h) that use 
>>smdk2410 board.
> 
> 
> I have forwarded your patch to David Müller who is the maintainer for
> the SMDK2410 board; I cannot test it myself.
> 
> 
>>I tested with MAKEALL ARM9 my patch.
>>I changed the frequency of internal clock of s3c2410 (for smdk2410 
>>borad) because (only) in this way the Linux Mizi kernel can boot correctly.
>>The patch is based on u-boot 0.4.8.
>>
>>This is my first contribution to open source and I hope that it is 
>>useful to someone.
> 
> 
> It is definitely useful, but I have a couple of questions:
> 
> * Which problem are you trying to address which is not  supported  by
>   the existing NAND code?

I have changed NAND code only to remove warning beacuse I don't use
some variable an then I rewrite "unsigned long nandptr = nand->IO_ADDR;" in
"unsigned long nandptr;  nandptr = nand->IO_ADDR;".

> 
> * Is it necessary to implement this in a processor specific way?

The boot from nand (without flash) is specific of s3c2410 cpu and so I
rewrite some part of cpu/arm920t/start.S (reset and copy from nand to ram).

> 
> * You add new configuration options like CONFIG_S3C2410_NAND_BOOT but
>   do not include any  dosumentation.  At  least,  please  provide  an
>   explantion  of these options for the README fie. If you feel longer
>   explanations are needed create a new file  doc/README.NAND-Boot  or
>   so.
> 

I have forgot!
When you want boot from nand-flash and not from frash you have to define
CONFIG_S3C2410_NAND_BOOT in your conifg file. This define is independent 
  to u-boot NAND support.

> 
> David, I've forwarded the patch to you. Can you please have a look at
> the implementation details? Thanks.
> 
> Best regards,
> 
> Wolfgang Denk
> 

Bye
Ginaluca