Linux/AM5718: Buffer exchange with DSP

rei

Part Number: AM5718
Other Parts Discussed in Thread: TMDXIDK5718

Tool/software: Linux

Hi.
My customers have two questions about sharing frame buffers between ARM/DSP.
They ran the sample project "big-data-ipc-demo-linux" in the SDK.
This project is:
First, share the buffer obtained from CMEM in SharedRegion1.
After that, I think that exchanging data between ARM / DSP by sending and receiving messages.

Question 1:
If I want to share 2MB or more of image data between ARM/DSP, are there any other way than this sample project?

They want to use DSP to process 12 bit grayscale data captured by ARM.
I want to pass the frame buffer obtained from the capture driver to the DSP copyless.
If we use the "big-data-ipc-demo-linux" method, I think we have to copy the data from the frame buffer.

Question 2:
Would you tell me if there is a way to pass frame buffer to DSP copyless.

OS : Ubuntu 16.04.4 LTS
SDK : PROCESSOR-SDK-LINUX-RT-AM57X 05_02_00_10
EVM : TMDXIDK5718
OptionLCD : TMDXIDK57X-LCD

Regards,
Rei

over 6 years ago

0 Rex Chang over 6 years ago

TI__Guru 50170 points

Hi, rei,

If you look at the big data example, it actually passed the local shared region address to the DSP. Upon receiving the message, DSP translates the address pointer based on its mapping of the shared region to get the data. There isn't any copy involved.

Rex

0 rei over 6 years ago in reply to Rex Chang

Mastermind 6155 points

Hi Rex
Thank you for your reply.
It means not to copy from buffer to shared area.

Question 1:
They want to pass the frame buffer data directly to the DSP.
(Don't use shared region)
Are there any method?

Question 2:
When exchanging large data between ARM and DSP.
are there any method other than this sample code?

Regards,

Rei

0 Rex Chang over 6 years ago in reply to rei

TI__Guru 50170 points

Hi, Rei,

There are other ways but not what you want. The big data example not only shows how not to copy data, but also in big data buffers.

You can use Messageq which only takes max payload of 449 bytes, and involves copying. If customer's application is to process grayscale data, is OpenCV an optioin?

http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components_OpenCV.html

Rex

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Linux/AM5718: Buffer exchange with DSP