Expected "channels" specification in the BSP's board_spec.xml but see nothing.

[okramer]

I'm learning about Intel's "channels" OpenCL extension for host-to-kernel and io-to-kernel communication. The training video says the specification of the board's available channels are in board_spec.xml. I looked in

intelFPGA_pro/19.3/hld/board/a10_ref/hardware/a10gx/board_spec.xml intelFPGA_pro/19.3/hld/board/a10_ref/hardware/a10gx_hostpipe/board_spec.xml

(I have an A10GX dev kit). The first board_spec.xml has no channels, while the second one has:

<channels><interface name="board" port="host_to_dev" type="streamsource" width="256" chan_id="host_to_dev"/><interface name="board" port="dev_to_host" type="streamsink" width="256" chan_id="dev_to_host"/></channels>

Is this for PCIe? What about ethernet IO? How do I use channels with this board

[MEIYAN_L_Intel]

Hi, 

These line is used for the BSP to support host channels. You can try create a loopback kernel which can read from host_to_dev channel and write to host_to_dev channel.

For more information, you can refer to the links below: 

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/opencl-sdk/ug-aocl-a10pciedk-platform.pdf

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/an/an831.pdf

Thanks

[okramer]

Thanks Mylee.

If I understand correctly, host-to-dev and dev-to-host channels are currently supported only by the "a10gx_hostpipe" BSP. When I invoke aoc, I need to use "-board=a10gx_hostpipe", correct? The "a10_ref" BSP does not support host<->dev channels?

What about ethernet? From the user guide you linked to above, it sounds like I'll need to define a new BSP based on "a10gx_hostpipe" that adds the ethernet capability as well. Does Intel perhaps provide a BSP with ethernet available, since the dev kit comes with ethernet?

What about OpenCL pipes? I suppose the BSP somehow needs to support host<->dev streaming via pipes. Does Intel use channels under the hood for the OpenCL pipes implementation? So in order for pipes to work, the BSP must provide corresponding channels? I willl most likely use pipes, not channels, so this question is the most important.

[MEIYAN_L_Intel · Accepted solution]

Hi,

Yes host-to-dev channel and dev-to-host are supported only by "a10gx_hostpipe"BSP.

For question "Does Intel perhaps provide a BSP with ethernet available, since the dev kit comes with ethernet?", i would need some time to check it internally.

The BSP support host-dec streaming via pipe. The channel is provided for pipe to work. There is no difference between pipe and channel, it only the name difference here.

Thanks

[MEIYAN_L_Intel]

Hi, 

After check internally, there is no Arria 10 BSP with ethernet available provided by Intel. 

To define the Arria 10GX with ethernet available, there is a document: "Stratix V network reference platform porting guide" that may be useful for you to define the ethernet available BSP. 

https://www.intel.com/content/www/us/en/programmable/documentation/ewa1404851957878.html#ewa1405102911782

To modify the Arria 10GX BSP, you may need to refer the document as below: 

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/an/an780.pdf

Thanks

[okramer]

I don't think aocl is seeing a10gx_hostpipe. When I do "aocl install", am I supposed to provide it the path to hostpipe BSP? My directory structure is:

~/intelFPGA_pro/19.3/hld/board/a10_ref board_env.xml bringup/ hardware/ a10gx/ board_spec.xml, ... a10gx_hostpipe/ board_spec.xml, ... linux64/ scripts/ source/

I ran aocl install $INTELFPGAOCLSDKROOT/board/a10_ref successfully, but when I do aocl diagnose acl0 I see:

... -------------------------------------------------------------------- BSP Diagnostics -------------------------------------------------------------------- Using Device with name: a10gx : Arria 10 Reference Platform (acla10_ref0) ...

The diagnostic passes, but the device name = "a10gx" worries me. In $INTELFPGAOCLSDK/board/a10_ref/hardware/a10gx_hostpipe/board_spec.xml, the device name is given as name="a10gx_hostpipe", while in a10gx/board_spec.xml, it is given as name="a10gx". Does this mean I'm accessing the wrong BSP? How do I install the a10gx_hostpipe BSP?

[MEIYAN_L_Intel]

Hi,

According to https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/opencl-sdk/ug-aocl-a10pciedk-platform.pdf in Chapter 1.2.1, you have to choose the reference platform board variants by including board=<board name> as your aoc command option.

Thanks