[U-Boot] Is there any full story about how to take advantage FDT function ?

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Gao Ya'nan]

And how to configure the kernel to minimize the code modification ?

I am porting U-Boot and Linux to a new board with a MPC875 processor
and two serial chips,  and U-Boot runs well now. I hear that the FDT
function can tell the kernel devices information more flexibly and
reduce the code modification indirectly.

But I didn't find enough materials to make my head clear, so any tip
is greatly appreciated.

Thanks.

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Jerry Van Baren]

Gao Ya'nan wrote:
> And how to configure the kernel to minimize the code modification ?
> 
> I am porting U-Boot and Linux to a new board with a MPC875 processor
> and two serial chips,  and U-Boot runs well now. I hear that the FDT
> function can tell the kernel devices information more flexibly and
> reduce the code modification indirectly.
> 
> But I didn't find enough materials to make my head clear, so any tip
> is greatly appreciated.
> 
> Thanks.

Hi Gao,

I'm not up on 8xx, but it may not have been pulled forward into the 
"powerpc" architecture (still "ppc").  The "powerpc" architecture switch 
is where linux/u-boot started using the FDT.

Best regards,
gvb

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Gao Ya'nan]

Hi, Jerry.

2009/9/6 Jerry Van Baren <gvb.uboot@gmail.com>:
> Gao Ya'nan wrote:
>>
>> And how to configure the kernel to minimize the code modification ?
>>
>> I am porting U-Boot and Linux to a new board with a MPC875 processor
>> and two serial chips, ?and U-Boot runs well now. I hear that the FDT
>> function can tell the kernel devices information more flexibly and
>> reduce the code modification indirectly.
>>
>> But I didn't find enough materials to make my head clear, so any tip
>> is greatly appreciated.
>>
>> Thanks.
>
> Hi Gao,
>
> I'm not up on 8xx, but it may not have been pulled forward into the
> "powerpc" architecture (still "ppc"). ?The "powerpc" architecture switch is
> where linux/u-boot started using the FDT.
>

I use U-Boot-V2009.8 and Linux-DENX-v2.6.30.3, and I can't find
arch/ppc any more. So, I think FDT will work well in MPC8xx platform.

But I don't know how to use it, perhaps I shoud try the standard
MPC885 configuration and dtb file.

> Best regards,
> gvb
>

Thanks.

Best regards

Gao Ya'nan

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Scott Wood]

On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
> I'm not up on 8xx, but it may not have been pulled forward into the 
> "powerpc" architecture (still "ppc").  The "powerpc" architecture switch 
> is where linux/u-boot started using the FDT.

8xx is supported in arch/powerpc.

-Scott

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Gao Ya'nan]

2009/9/10 Scott Wood <scottwood@freescale.com>:
> On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
>> I'm not up on 8xx, but it may not have been pulled forward into the
>> "powerpc" architecture (still "ppc"). ?The "powerpc" architecture switch
>> is where linux/u-boot started using the FDT.
>
> 8xx is supported in arch/powerpc.

Yes, I have add CONFIG_OF_LIBFDT and CONFIG_OF_BOARD_SETUP for the FDT
support which is missing in U-Boot-v2009.08, and it works well, but I
found none complete document on how to write a dts file and add
special device in it.

Any tips? Thanks

Gao Ya'nan

>
> -Scott
>

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Scott Wood]

Gao Ya'nan wrote:
> 2009/9/10 Scott Wood <scottwood@freescale.com>:
>> On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
>>> I'm not up on 8xx, but it may not have been pulled forward into the
>>> "powerpc" architecture (still "ppc").  The "powerpc" architecture switch
>>> is where linux/u-boot started using the FDT.
>> 8xx is supported in arch/powerpc.
> 
> Yes, I have add CONFIG_OF_LIBFDT and CONFIG_OF_BOARD_SETUP for the FDT
> support which is missing in U-Boot-v2009.08, and it works well, but I
> found none complete document on how to write a dts file and add
> special device in it.
> 
> Any tips? Thanks

See Documentation/powerpc/booting-without-of.txt, 
Documentation/powerpc/dts-bindings, and the ePAPR specification for 
information on the content of device trees.

-Scott

[U-Boot] Is there any full story about how to take advantage FDT function ?

[Gao Ya'nan]

2009/9/10 Scott Wood <scottwood@freescale.com>:
> Gao Ya'nan wrote:
>>
>> 2009/9/10 Scott Wood <scottwood@freescale.com>:
>>>
>>> On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
>>>>
>>>> I'm not up on 8xx, but it may not have been pulled forward into the
>>>> "powerpc" architecture (still "ppc"). ?The "powerpc" architecture switch
>>>> is where linux/u-boot started using the FDT.
>>>
>>> 8xx is supported in arch/powerpc.
>>
>> Yes, I have add CONFIG_OF_LIBFDT and CONFIG_OF_BOARD_SETUP for the FDT
>> support which is missing in U-Boot-v2009.08, and it works well, but I
>> found none complete document on how to write a dts file and add
>> special device in it.
>>
>> Any tips? Thanks
>
> See Documentation/powerpc/booting-without-of.txt,
> Documentation/powerpc/dts-bindings, and the ePAPR specification for
> information on the content of device trees.

I miss the later two, thanks for your tips.

Gao.

>
> -Scott
>