[U-Boot-Users] NAND access via custom interface

[U-Boot-Users] NAND access via custom interface

[Jack Hab]

Dear All,
I'm porting U-Boot to our hardware based on Virtex-II FGPA. We have NAND
device which cannot be accessed directly but only via our interface which
takes care of all the control lines and sends the address/command/data bytes
automatically.
I understand, low-level macros like NAND_CLRCLE can be skipped.

Will it be OK if I implemet only NAND_WAIT_READY, WRITE_NAND_xxx and
READ_NAND macros? Or anything else is required.

Do I need to set any structures manually? I couldn't find who populates
struct nand_chip with info, at which stages it occurs.

Thanks.
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[U-Boot-Users] NAND access via custom interface

[Stefan Roese]

Hi Jack,

On Thursday 19 October 2006 14:56, Jack Hab wrote:
> I'm porting U-Boot to our hardware based on Virtex-II FGPA. We have NAND
> device which cannot be accessed directly but only via our interface which
> takes care of all the control lines and sends the address/command/data
> bytes automatically.

So you have a NAND flash controller on your board, right?

> I understand, low-level macros like NAND_CLRCLE can be skipped.
>
> Will it be OK if I implemet only NAND_WAIT_READY, WRITE_NAND_xxx and
> READ_NAND macros? Or anything else is required.

Seems you are looking at the "old" legacy NAND driver which should _not_ be 
used anymore. Please use the "new" NAND driver which makes it also quite easy 
to support NAND flash controllers. As an example implementation please take a 
look at the cpu/ppc4xx/ndfc.c driver. It's used in the AMCC "sequoia" 
(440EPx) board. Another boardspecific example is the 
board/prodrive/pdnb3/nand.c driver used by the pdnb3 board.

Best regards,
Stefan

[U-Boot-Users] NAND access via custom interface

[Jack Hab]

Yes I have all the defines related to the NAND.
I understand the stuff in cmd_nand.c is not called directly from U-Boot
code, so what's the mechanism which includes this file in the link stage?


On 10/23/06, Stefan Roese <sr@denx.de> wrote:
>
> Hi Jack,
>
> On Monday 23 October 2006 13:43, you wrote:
> > I've implemented the NAND interface with functions registerd in
> nand_chip
> > struct. All compiles fine but somehow the cmd_nand.c is not getting
> linked.
> > I get the U-Boot image with all my nand flash functions inside but since
> > cmd_nand.c is not linked, U_BOOT_CMD does not register the nand
> commands.
> > I have
> >
> > #define CONFIG_COMMANDS    (CONFIG_CMD_DFL | CFG_CMD_NAND
> >
> > in my boardconfig.h
> >
> > Is there anything else needed?
>
> Do you have something like:
>
> /*
> * NAND-FLASH stuff
> */
> #define CFG_MAX_NAND_DEVICE     1
> #define NAND_MAX_CHIPS          1
> #define CFG_NAND_BASE           0x51000000      /* NAND FLASH Base Address
> */
>
> in your config file? And please make sure that you don't
> have "CFG_NAND_LEGACY" defined.
>
> BTW: Please keep send those kind of messages to the list and not _only_ to
> me.
> Thanks.
>
> Best regards,
> Stefan
>
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[U-Boot-Users] NAND access via custom interface

[Stefan Roese]

On Monday 23 October 2006 14:12, Jack Hab wrote:
> Yes I have all the defines related to the NAND.
> I understand the stuff in cmd_nand.c is not called directly from U-Boot
> code,

It _is_ called from U-Boot code. Via the "nand read/write/bad ..." commands.

> so what's the mechanism which includes this file in the link stage? 

Nothing special. Works for me just fine as is.

Best regards,
Stefan