I.MX 8M Mini remoteproc m4 in Yocto

[Gblankers]

Hi,

I have a stm developper kit for which I built an image with yocto, here the remoteproc framework works out of the box. So I though that it would be as easy for an I.MX 8M Mini but it turns out it isn't. 

The remoteproc framework seems to be present in my image but it doesn't detect the co-processor. I have changed the bsp to meta-freescale and made sure remoteproc is enabled in the kernel, are there any additional steps that I am missing?

Thanks,

[AldoG]

Hello,

you may refer to the latest Linux documentation available here:
https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applicat...

Specially the Linux Reference Manual, chapter 2.8 Remote Processor Messaging:
https://www.nxp.com/docs/en/reference-manual/IMX_REFERENCE_MANUAL.pdf

Also, please note that for i.MX 8M platforms, the root clock for M7/M4 must be kept always enabled by Linux to load the firmware code and start Cortex M7/M4. By default, NXP Linux BSP keeps the root clock enabled for the M core when it is started from U-Boot. Otherwise, if you need to firstly start the M core from the Linux booting phase, the clock driver (drivers/clk/imx/clk-composite-8m.c) must be updated to always skip the gate registration to keep the root clock always enabled for the M core.

The above is an extract of the application note AN5317, available here:
https://www.nxp.com/docs/en/application-note/AN5317.pdf

Best regards,
Aldo.