Device Tree

Device Tree

[Georg Schardt]

Hi,

im searching for informations about the flatten device trees. the only 
thing i know is, that the device tree is a kind of data-structure which 
the bios or bootloader gives to the operation system.

until now, i boot linux with uboot without a device tree, but newer 
kernel wants a devicetree, i think ??
i use a virtex4 board with an integrated powerpc

how can i create the device tree file ?
how must the linux kernel be configured ?
is there a good internet page with informations ?


thanks
regards
georg

Re: Device Tree

[Josh Boyer]

On Tue, Sep 09, 2008 at 05:43:12PM +0200, Georg Schardt wrote:
> Hi,
>
> im searching for informations about the flatten device trees. the only  
> thing i know is, that the device tree is a kind of data-structure which  
> the bios or bootloader gives to the operation system.
>
> until now, i boot linux with uboot without a device tree, but newer  
> kernel wants a devicetree, i think ??
> i use a virtex4 board with an integrated powerpc
>
> how can i create the device tree file ?
> how must the linux kernel be configured ?
> is there a good internet page with informations ?

In the kernel, look at Documentation/powerpc/booting-without-of.txt

You could also read the "A Symphony of Flavours: Using the device tree to
describe embedded hardware" paper on page 27 of:

http://www.linuxsymposium.org/2008/ols-2008-Proceedings-V2.pdf

josh

RE: Device Tree

[John Linn]

Hi Georg,

Our git tree, git://git.xilinx.com, has support for the ML405 board
which is a V4 board. The following wiki page, http://xilinx.wikidot.com,
shows how to generate a device tree for the kernel and other details
you'll need.

The kernel from our git tree is configured for the device tree using the
default kernel configuration.

The mainline kernel is now more up to date also as we got many of the
changes into the mainline, but we are still working on some of the
device drivers.

Thanks,
John

> -----Original Message-----
> From: linuxppc-embedded-bounces+john.linn=3Dxilinx.com@ozlabs.org
[mailto:linuxppc-embedded-
> bounces+john.linn=3Dxilinx.com@ozlabs.org] On Behalf Of Georg Schardt
> Sent: Tuesday, September 09, 2008 9:43 AM
> To: linuxppc-embedded@ozlabs.org
> Subject: Device Tree
> =

> Hi,
> =

> im searching for informations about the flatten device trees. the only
> thing i know is, that the device tree is a kind of data-structure
which
> the bios or bootloader gives to the operation system.
> =

> until now, i boot linux with uboot without a device tree, but newer
> kernel wants a devicetree, i think ??
> i use a virtex4 board with an integrated powerpc
> =

> how can i create the device tree file ?
> how must the linux kernel be configured ?
> is there a good internet page with informations ?
> =

> =

> thanks
> regards
> georg
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded


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hments. Delete this email message and any attachments immediately.

Re: Device Tree

[Georg Schardt]

Hi John,

yes, i found the wiki link in another post of you. nice , thank you.
can you tell me how to generate the dts file in the EDK 10.2 ?  i have 
read that the gen_mhs_devtree script is now integrated ? i see no 
menu-item or config option ?

regards
georg



John Linn wrote:
> Hi Georg,
>
> Our git tree, git://git.xilinx.com, has support for the ML405 board
> which is a V4 board. The following wiki page, http://xilinx.wikidot.com,
> shows how to generate a device tree for the kernel and other details
> you'll need.
>
> The kernel from our git tree is configured for the device tree using the
> default kernel configuration.
>
> The mainline kernel is now more up to date also as we got many of the
> changes into the mainline, but we are still working on some of the
> device drivers.
>
> Thanks,
> John
>
>   
>> -----Original Message-----
>> From: linuxppc-embedded-bounces+john.linn=xilinx.com@ozlabs.org
>>     
> [mailto:linuxppc-embedded-
>   
>> bounces+john.linn=xilinx.com@ozlabs.org] On Behalf Of Georg Schardt
>> Sent: Tuesday, September 09, 2008 9:43 AM
>> To: linuxppc-embedded@ozlabs.org
>> Subject: Device Tree
>>
>> Hi,
>>
>> im searching for informations about the flatten device trees. the only
>> thing i know is, that the device tree is a kind of data-structure
>>     
> which
>   
>> the bios or bootloader gives to the operation system.
>>
>> until now, i boot linux with uboot without a device tree, but newer
>> kernel wants a devicetree, i think ??
>> i use a virtex4 board with an integrated powerpc
>>
>> how can i create the device tree file ?
>> how must the linux kernel be configured ?
>> is there a good internet page with informations ?
>>
>>
>> thanks
>> regards
>> georg
>> _______________________________________________
>> Linuxppc-embedded mailing list
>> Linuxppc-embedded@ozlabs.org
>> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>>     
>
>
> This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.
>
>
>   

RE: Device Tree

[John Linn]

It is not integrated into the EDK, you need to pull it from our git tree
and use it from the EDK.

-- John

Here's part of the wiki page.

Generating a Device Tree

The Linux kernel from the git tree has device tree files, ml507.dts and
ml405.dts, in the arch/powerpc/boot/dts directory which are designed to
work with the hardware reference designs available from this site. Users
who have a Xilinx board, ML405 or ML507, should build the Linux kernel
using the provided dts file to get a solid baseline before generating a
new device tree file. After a baseline is established, the new dts files
can be compared to the existing to verify any differences.

The page, Generating A Device Tree, has details on how to generate a
device tree for the arch/powerpc Linux kernel.




> -----Original Message-----
> From: Georg Schardt [mailto:schardt@team-ctech.de]
> Sent: Tuesday, September 09, 2008 12:19 PM
> To: John Linn
> Cc: linuxppc-embedded@ozlabs.org
> Subject: Re: Device Tree
> =

> Hi John,
> =

> yes, i found the wiki link in another post of you. nice , thank you.
> can you tell me how to generate the dts file in the EDK 10.2 ?  i have
> read that the gen_mhs_devtree script is now integrated ? i see no
> menu-item or config option ?
> =

> regards
> georg
> =

> =

> =

> John Linn wrote:
> > Hi Georg,
> >
> > Our git tree, git://git.xilinx.com, has support for the ML405 board
> > which is a V4 board. The following wiki page,
http://xilinx.wikidot.com,
> > shows how to generate a device tree for the kernel and other details
> > you'll need.
> >
> > The kernel from our git tree is configured for the device tree using
the
> > default kernel configuration.
> >
> > The mainline kernel is now more up to date also as we got many of
the
> > changes into the mainline, but we are still working on some of the
> > device drivers.
> >
> > Thanks,
> > John
> >
> >
> >> -----Original Message-----
> >> From: linuxppc-embedded-bounces+john.linn=3Dxilinx.com@ozlabs.org
> >>
> > [mailto:linuxppc-embedded-
> >
> >> bounces+john.linn=3Dxilinx.com@ozlabs.org] On Behalf Of Georg Schardt
> >> Sent: Tuesday, September 09, 2008 9:43 AM
> >> To: linuxppc-embedded@ozlabs.org
> >> Subject: Device Tree
> >>
> >> Hi,
> >>
> >> im searching for informations about the flatten device trees. the
only
> >> thing i know is, that the device tree is a kind of data-structure
> >>
> > which
> >
> >> the bios or bootloader gives to the operation system.
> >>
> >> until now, i boot linux with uboot without a device tree, but newer
> >> kernel wants a devicetree, i think ??
> >> i use a virtex4 board with an integrated powerpc
> >>
> >> how can i create the device tree file ?
> >> how must the linux kernel be configured ?
> >> is there a good internet page with informations ?
> >>
> >>
> >> thanks
> >> regards
> >> georg
> >> _______________________________________________
> >> Linuxppc-embedded mailing list
> >> Linuxppc-embedded@ozlabs.org
> >> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> >>
> >
> >
> > This email and any attachments are intended for the sole use of the
named recipient(s) and
> contain(s) confidential information that may be proprietary,
privileged or copyrighted under
> applicable law. If you are not the intended recipient, do not read,
copy, or forward this email
> message or any attachments. Delete this email message and any
attachments immediately.
> >
> >
> >
> =



This email and any attachments are intended for the sole use of the named r=
ecipient(s) and contain(s) confidential information that may be proprietary=
, privileged or copyrighted under applicable law. If you are not the intend=
ed recipient, do not read, copy, or forward this email message or any attac=
hments. Delete this email message and any attachments immediately.

Re: Device Tree

[Sébastien Chrétien]

Thank for your answers.
Sébastien

Matt Sealey a écrit :
> Benjamin Herrenschmidt wrote:
>> On Tue, 2008-09-30 at 18:08 -0500, Matt Sealey wrote:
>>> It's far more common than people might think at first glance. With x86
>>> I am sure it would benefit the platform a little more if the OF support
>>> was in-line with the shared code between PPC and SPARC (and now I 
>>> guess,
>>> ARM) but nevertheless it's an Open Firmware platform and something that
>>> appeared not too long ago.
>>>
>>> OF is still a going concern; if you want a nice flexible firmware, why
>>> not use it? Most of the implementations are open source (FirmWorks and
>>> CodeGen trees, and the Sun reference design) too.
>>
>> And SLOF :-)
>
> I guess OpenBIOS counts too :)
>

Re: Device Tree

[Matt Sealey]

Benjamin Herrenschmidt wrote:
> On Tue, 2008-09-30 at 18:08 -0500, Matt Sealey wrote:
>> It's far more common than people might think at first glance. With x86
>> I am sure it would benefit the platform a little more if the OF support
>> was in-line with the shared code between PPC and SPARC (and now I guess,
>> ARM) but nevertheless it's an Open Firmware platform and something that
>> appeared not too long ago.
>>
>> OF is still a going concern; if you want a nice flexible firmware, why
>> not use it? Most of the implementations are open source (FirmWorks and
>> CodeGen trees, and the Sun reference design) too.
> 
> And SLOF :-)

I guess OpenBIOS counts too :)

-- 
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations

Re: Device Tree

[Benjamin Herrenschmidt]

On Tue, 2008-09-30 at 18:08 -0500, Matt Sealey wrote:
> It's far more common than people might think at first glance. With x86
> I am sure it would benefit the platform a little more if the OF support
> was in-line with the shared code between PPC and SPARC (and now I guess,
> ARM) but nevertheless it's an Open Firmware platform and something that
> appeared not too long ago.
> 
> OF is still a going concern; if you want a nice flexible firmware, why
> not use it? Most of the implementations are open source (FirmWorks and
> CodeGen trees, and the Sun reference design) too.

And SLOF :-)

Cheers,
Ben.

Re: Device Tree

[Matt Sealey]

Gerald Van Baren wrote:
> Matt Sealey wrote:
 >>
>> The Toshiba TOPAS910 ARM development board also runs Open Firmware and
>> contains patches to support OF device trees.
>>
>> I dare say there might be an x86 box or two out there, too. But they
>> have ACPI tables too which is far more common..
> 
> More than a box or two: lots of OLPC XOs out there now.  ;-)
>     <http://wiki.laptop.org/go/Open_Firmware>

I was thinking more in a platform kind of numbers rather than a sales
kind of numbers, but you're right.

It's far more common than people might think at first glance. With x86
I am sure it would benefit the platform a little more if the OF support
was in-line with the shared code between PPC and SPARC (and now I guess,
ARM) but nevertheless it's an Open Firmware platform and something that
appeared not too long ago.

OF is still a going concern; if you want a nice flexible firmware, why
not use it? Most of the implementations are open source (FirmWorks and
CodeGen trees, and the Sun reference design) too.

-- 
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations

Re: Device Tree

[Gerald Van Baren]

Matt Sealey wrote:
>
> Sergei Shtylyov wrote:
>> Hello.
>>
>> S=E9bastien Chr=E9tien wrote:
>>> Hello,
>>> I have a question about Device Tree.
>>> Is Device Tree found only only on Linux Powerpc ?
>>
>>   Not only Linux as it's a part of Open Firmware which is also used at
>> least on SPARC.
>
> The Toshiba TOPAS910 ARM development board also runs Open Firmware and
> contains patches to support OF device trees.
>
> I dare say there might be an x86 box or two out there, too. But they
> have ACPI tables too which is far more common..

More than a box or two: lots of OLPC XOs out there now.  ;-)
    <http://wiki.laptop.org/go/Open_Firmware>

Best regards,
gvb

Re: Device Tree

[Matt Sealey]

Sergei Shtylyov wrote:
> Hello.
> 
> Sébastien Chrétien wrote:
>> Hello,
>> I have a question about Device Tree.
>> Is Device Tree found only only on Linux Powerpc ?
> 
>   Not only Linux as it's a part of Open Firmware which is also used at 
> least on SPARC.

The Toshiba TOPAS910 ARM development board also runs Open Firmware and
contains patches to support OF device trees.

I dare say there might be an x86 box or two out there, too. But they
have ACPI tables too which is far more common..

-- 
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations

Re: Device Tree

[Benjamin Herrenschmidt]

On Mon, 2008-09-29 at 08:24 +0200, Sébastien Chrétien wrote:
> Hello,
> I have a question about Device Tree.
> Is Device Tree found only only on Linux Powerpc ?

Sparc also uses open firmware and shares some of the device-tree
handling code with powerpc in linux. Other operating systems on those
platforms also use it (AIX, Solaris, MacOS, ...)

I think the proposed new Xilinx microblaze architecture also uses it,
and at least on x86, the OLPC has an Open Firmware implementation though
it doesn't use the device-tree the way we do currently on powerpc and
sparc and has its own interface to the firmware.

Ben.

Re: Device Tree

[Sergei Shtylyov]

Hello.

Sébastien Chrétien wrote:

> I have a question about Device Tree.
> Is Device Tree found only only on Linux Powerpc ?

   Not only Linux as it's a part of Open Firmware which is also used at 
least on SPARC.

WBR, Sergei

Re: Device Tree

[Sergei Shtylyov]

Hello.

Sébastien Chrétien wrote:
> Hello,
> I have a question about Device Tree.
> Is Device Tree found only only on Linux Powerpc ?

   Not only Linux as it's a part of Open Firmware which is also used at 
least on SPARC.

WBR, Sergei

Device Tree

[Sébastien Chrétien]

Hello,
I have a question about Device Tree.
Is Device Tree found only only on Linux Powerpc ?

Thanks
Sébastien