How to use mailbox ip on linux?

[Julian]

We often use mailboxes between microblaze and zynq or between microblaze and microblaze when using freertos or baremetal.

Now we need to use the mailbox on linux, but we did not find the mailbox device in the /dev. How do I use it?

Is it necessary to use rpmsg and other openamp functions in Linux?

[Julian]

No linux driver for MB?

[ksloatdesignlinx]

Looking at the Linux source tree, it does not appear so. Even if there was, I don't think it would show up in /dev like a char device. I believe mailbox controller drivers are intended to be manipulated by other client drivers within the kernel:

https://www.kernel.org/doc/Documentation/mailbox.txt

Looking at the datasheet, the device seems simple enough that you can probably memory map the register space via UIO or similar and write a simple userspace driver application to interface to it.

[stephenm]

I have used the UIO in the past for this

[JFP]

Hi @stephenm 

Could you go deeper into that approach? or provide a reference? In my mind openAMP should be the choice (because it's the only one I can picture), so I am quite interested on yours.

Thanks,
Jose.