imx8mp bind csi, isp, dsi to M7 cortex. is it possible?

[efly]

Hello,

We are working on a device that needs to have a camera feed displayed on a screen in a couple of seconds max.  

I was wondering if it is possible to bind the display interface (CSI, ISP, and DSI) to the M7 cortex and boot an RTOS quickly.

Any thoughts ?

thank you 

[terry_lv]

Hi,

  From the diagram you provided, it seems that you want to use M7 to handle both the camera and display simultaneously?

  Actually, I'm not very sure if this is possible and how difficult it would be to implement.

  In my opinion, there're 3 problems that we need to resolve here:

1. Fast boot of M7 core.
2. SDK drivers of CSI, ISP, and DSI.
3. M7 core and DDR performance.

  For 1, I think it's OK and you can refer to AN4049:
https://www.nxp.com/webapp/Download?colCode=AN14049&location=null

  For 2, I noticed that there's no CSI, ISP and DSI drivers in 8MP SDK. So you might need to port these drivers from other SoCs' SDK, u-boot or kernel. 
  I also checked i.MX RT SDKs, it seems these drivers are not implemented. The DSI driver can be ported from u-boot. CSI and ISP drivers need to be ported from kernel. It does need some efforts.
  Generally, the difficulty of porting is Other SDK < u-boot < kernel.

  For 3, for this case, the TCM should not be enough. I'm not sure whether the DDR and core performance is sufficient. We should do some test to confirm.

  Thanks!

Regards

Terry

[efly]

I guess it is better to put our efforts into linux boot time reduction at this stage.

Thank you so much for you input @terry_lv 

Regards,

E

[terry_lv]

Hi efly,

  There're two ANs you can refer to for fastboot of kernel:

AN14093 (https://www.nxp.com/docs/en/application-note/AN14093.pdf)

AN14113 (https://www.nxp.com/webapp/Download?colCode=AN14113&location=null)

  Both describes different ways to implement falcon mode in u-boot to reduce boot time. Moreover, AN14093 also talks about kernel optimizations.

  Hope this can help you.

  Thanks!

Regards

Terry

[efly]

@terry_lv it would be highly appreciated if you can help with this !

[JosephAtNXP]

Hi,

Thank you for your interest in NXP Semiconductor products,

It's not possible to handle CSI nor DSI in Cortex-M, only Cortex-A.

Regards

[efly]

thank you for the reply Joseph.

Is this a software or hardware limitation?

I found this post on an IMX8MN

https://community.nxp.com/t5/i-MX-Processors/Use-M7-core-to-control-display-on-iMX8MN/m-p/1208041