Parallella as development board

Any technical questions about the Epiphany chip and Parallella HW Platform.

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Parallella as development board

Postby zodane » Fri Dec 04, 2015 12:58 pm

Hello,
It has been almost a year now since i bought my Parallella 7020.
If i buy a porcupine and a jtag cable, can i use my board for standalone application (without Os).
how can i program the epiphany (in standalone mode), maybe one arm should drive the epiphany while the second will run application, is the epiphany worth that!!


Regards
zodane
 
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Re: Parallella as development board

Postby sebraa » Fri Dec 04, 2015 3:27 pm

The Zynq boots from SD card (by loading kernel and bitstream), you don't need a Porcupine to change that. The Epiphany chip is connected to the PL part (FPGA) of the Zynq. If you implement the eLink protocol and a kernel loader in the FPGA, then you won't need the ARM cores at all to run stuff on the Epiphany. Lots of work, little gain.

I am not sure what you actually want.
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Re: Parallella as development board

Postby zodane » Fri Dec 04, 2015 4:59 pm

Thank you for feedback Sebraa.
I want a full communication between the 2 ARM cores , epiphany and PL.
I want to be able to debug software and hardware.
And finally i don't need an operating system (bare metal application).
zodane
 
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Re: Parallella as development board

Postby sebraa » Sun Dec 06, 2015 10:08 pm

zodane wrote:And finally i don't need an operating system (bare metal application).
Don't need or don't want? If it's the latter, you'd need a good justification for the additional amount of work you need to do.
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Re: Parallella as development board

Postby zodane » Mon Dec 07, 2015 8:23 am

sebraa wrote:
zodane wrote:And finally i don't need an operating system (bare metal application).
Don't need or don't want? If it's the latter, you'd need a good justification for the additional amount of work you need to do.


This is for my Phd work, where my proposition should be optimized on terms of resources(power and space). In my case all i need is to read a video file from sd card perform some processing on it (PS, PL) an why not compare the performance when using epiphany.
Any idea are welcomed.
zodane
 
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Re: Parallella as development board

Postby sebraa » Mon Dec 07, 2015 2:00 pm

You didn't answer the question.

Reading a video file from SD card and doing some processing on it is easy, given Linux.
Using the Epiphany for the processing can be doable, incredibly hard or plainly impossible, given Linux and eSDK.
Changing the FPGA bitstream to do the processing can be done, given Linux. Other's have done it.

Ditching Linux on the PS needs a really good justification.
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Re: Parallella as development board

Postby zodane » Mon Dec 07, 2015 2:39 pm

sebraa wrote:You didn't answer the question.


I've already participate in a training for Zynq 7000
where we have programmed and debugged PS in standalone mode( without OS) .
SW_Zynq_LECTURES_free.jpg
SW_Zynq_LECTURES_free.jpg (61.74 KiB) Viewed 13069 times

The trainer told as that usually, there is no need for OS except if we gone run an application that run on both cores or a driver for some peripheral which is not the case.
Besides power optimization is very important for publication. So why ruining extra application on ARM while i don't need it. I'm looking for the simplest way to get done the job with a an impacted publication.
zodane
 
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Re: Parallella as development board

Postby sebraa » Mon Dec 07, 2015 7:30 pm

zodane wrote:The trainer told as that usually, there is no need for OS except if we gone run an application that run on both cores or a driver for some peripheral which is not the case.
In my world, it is better to use an operating system as soon as the system is more complex than what you are willing to teach your application.

zodane wrote:Besides power optimization is very important for publication.
So basically, the answer to my question is "I don't want an operating system, because of better/higher impact publications". Fair enough.

To go back to your original question:
zodane wrote:If i buy a porcupine and a jtag cable, can i use my board for standalone application (without Os).
Yes.


zodane wrote:how can i program the epiphany (in standalone mode), maybe one arm should drive the epiphany while the second will run application, is the epiphany worth that!!
Maybe, maybe not. Each eCore can live on its own as soon as it has code to execute. You don't need to "drive" the Epiphany with an ARM core, other than to kickstart it or to provide input/output data (although that could be done using the PL as well). Epiphany-kernels are bare-metal applications anyway. Whether the Epiphany is worth the effort depends highly on what you actually want to do, that is, whether it is possible to efficiently utilize the Epiphany system for whatever you want to do.


Basically, you need to re-implement some parts of the eSDK as a bare-metal application to be able to communicate the kernels to the Epiphany and start them. So you need to implement a communication infrastructure between PS, PL and Epiphany (whereas the Epiphany part is fixed and the PL part can be reused). The JTAG interface of the Porcupine is probably a necessity in that case, I agree.
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Re: Parallella as development board

Postby zodane » Tue Dec 08, 2015 1:11 pm

Thank you Sebraa i will buy a porcupine daughter card + a hs2 jtag from digilent and see what can i do.
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