Linux/PROCESSOR-SDK-AM335X: Simple design reference

harel ashwal

Tool/software: Linux

LK"I

Hi TI,

We need to build our own board , which is quite simple one , it consist of : 512Mb RAM , 4GB eMMC , Gbit ethernet , 6 UARTs , 1 SPI , I2C.

Is there any reference by TI for the harware and the linux package for such combination ? (no need for audio nor BT/Wifi/SD card etc....)

Harel

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

Reference designs can be found here: processors.wiki.ti.com/.../AM335x_Boards
The Linux SDK can be downloaded here: software-dl.ti.com/.../index_FDS.html

0 harel ashwal over 8 years ago in reply to Biser Gatchev-XID

Intellectual 310 points

LK"I

I already been there... didn't find anything to match my requirment : 512Mb RAM , 4GB eMMC , Gbit ethernet , 6 UARTs , 1 SPI , I2C.

0 Biser Gatchev-XID over 8 years ago in reply to harel ashwal

TI__Guru**** 393215 points

You cannot expect to find a reference design exactly to your requirements. You can also check the Beaglebone Black design: elinux.org/Beagleboard:BeagleBoneBlack

0 harel ashwal over 8 years ago in reply to Biser Gatchev-XID

Intellectual 310 points

LK"I

I See,

What do I need to do (in terms of linux pakcage changes) in order to make the linux works with a diffrent PHY (for instance 1Gbit instead of BeagleBoneBlack 100Mb).

If I understand currently, I need to change the device tree to support the new PHY , and to make sure the driver is aviliable at the linux kernel?

Harel

0 Biser Gatchev-XID over 8 years ago in reply to harel ashwal

TI__Guru**** 393215 points

Yes, this is correct.

0 harel ashwal over 8 years ago in reply to Biser Gatchev-XID

Intellectual 310 points

LK"I

Okay,

Assuming I'm going to use standard RGMII Gbit ethernet PHY chip , and my reference design is beagleboneblack.

what what do I need to change with the exiting device tree to make it work with the Gbit PHY?

Harel

0 Biser Gatchev-XID over 8 years ago in reply to harel ashwal

TI__Guru**** 393215 points

You can use the AM335x GP EVM or Starter Kit device trees for reference. Both boards use RGMII Gigabit PHYs.

0 harel ashwal over 8 years ago in reply to Biser Gatchev-XID

Intellectual 310 points

LK"I

Currect me if i'm wrong, both of those use the Ethernet switch capability, (and therefore define two macs).

Is there any reference for a single mac? (without Ethernet switch?)

Harel

0 Biser Gatchev-XID over 8 years ago in reply to harel ashwal

TI__Guru**** 393215 points

The Beaglebone Black is a single Ethernet port solution. My suggestion was that you use the device trees I posted above for reference how RGMII is defined.

0 harel ashwal over 8 years ago in reply to Biser Gatchev-XID

Intellectual 310 points

LK"I

Sorry I'm confused here.

I understand that the above solutions has RGMII interfcace, but the use dual Ethernet channels (for Ethernet switch capabilities).

I don't need this functionality, just a SINGLE RGMII ethernet interface .

Is there any reference for this???

Harel

0 Biser Gatchev-XID over 8 years ago in reply to harel ashwal

TI__Guru**** 393215 points

No, you need to configure it yourself.

0 harel ashwal over 8 years ago in reply to Biser Gatchev-XID

Intellectual 310 points

I'm about to use this device : 88E6431 by Marvell (Gbit Ethernet Switch via RGMII)
I've found the driver for BBB at:
github.com/.../mv88e6xxx.c

Is the changes in the device tree are similar to TI Starter Kit ?
How do I "tell" the linux to use the above driver??
(p.s. since this is unamanged Ethernet Switch it should be treated as a Gbit Ethernet PHY)

Harel

0 Yordan Kovachev over 8 years ago in reply to harel ashwal

TI__Guru**** 161600 points

Hi Harel,

This driver is present in the latest Linux sdk for am335x devices.
Have a look at drivers/net/dsa/Kconfig, you need to add:
CONFIG_NET_DSA_MV88E6XXX=y
to build the driver into the kernel image. In general you tell the kernel to use a particular driver, with compatible="driver name" in the dts. However mv88e6xxx.c doesn't seem to support this feature, so just adding the above to tisdk_am335x-evm_defconfig should be enough.

Best Regards,
Yordan

0 harel ashwal over 8 years ago in reply to Yordan Kovachev

Intellectual 310 points

Thanks,

and what about RGMII insead of MII ??

Harel

0 harel ashwal over 8 years ago in reply to harel ashwal

Intellectual 310 points

I'm using BeagleBone Black based linux (and not the EVM)
So which Config file do I need to change?

Harel

0 Biser Gatchev-XID over 8 years ago in reply to harel ashwal

TI__Guru**** 393215 points

This forum supports only the TI released SDK: www.ti.com/.../PROCESSOR-SDK-AM335X No other Linux releases are supported here.

0 Rogerio Almeida over 8 years ago in reply to harel ashwal

TI__Mastermind 26215 points

Please check beagleboard.org web site for more details.

0 harel ashwal over 8 years ago in reply to Yordan Kovachev

Intellectual 310 points

LK"I

Thanks Yordan,
I've found the same definition with BBB config file - bb.org_defconfig (currently set to =m)
should i also switch the CONFIG_NET_DSA to y?
currently the line is :

CONFIG_NET_DSA=m

Harel

0 Yordan Kovachev over 8 years ago in reply to harel ashwal

TI__Guru**** 161600 points

Hi Harel,

should i also switch the CONFIG_NET_DSA to y?

Yes, try building the module into the kernel zImage.

Best Regards,
Yordan

0 harel ashwal over 8 years ago in reply to Yordan Kovachev

Intellectual 310 points

Thanks Yordan,

Just one thing I need to understand,

How linux kernel knows to take that driver and not the "default" 10/100 Ethernet driver?

Is there any more lines in the configuration I should change? (like setting something else from y to m ?)

Harel

0 Yordan Kovachev over 8 years ago in reply to harel ashwal

TI__Guru**** 161600 points

Hi,

you should also add the compatible support to the driver & its dts entry. See the following patch for reference:
patchwork.kernel.org/.../

Best Regards,
Yordan

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Linux/PROCESSOR-SDK-AM335X: Simple design reference