PRU RemoteProc communication initialization TI Kernel (3.14.26)

Tim Michals

I've downloaded PRU software package and can load PRU1 via modprobe pruss_remoteproc. Everything is working fine, gpio pins toggling etc. Now I'm trying to configure a virtio and rpmsg working:

- How to setup vring's via the api in pru_vring.c

- How to setup the resource table to configure tx/rx vrings

- Basic dispatch loop to process vrings in the PRU.

Is there an example I'm missing to show this? Lab 4 does have some configuration on this, does not configure vrings etc.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Tim,

Kernel 3.14 is not supported at this time. Latest kernel release that's supported by TI is 3.12.10.

0 Tim Michals over 10 years ago in reply to Biser Gatchev-XID

Intellectual 305 points

OK, using 3.12.10 how to setup remoteproc support fro PRU?

0 RonB over 10 years ago in reply to Tim Michals

TI__Mastermind 30416 points

Tim,

I'm afraid you're a bit ahead of us on this. We are trying to get an example of this done this quarter, in addition to providing a "generic" kernel driver that will open interface with userspace.

0 Tim Michals over 10 years ago in reply to RonB

Intellectual 305 points

OK, is there a way to get some basic information on the basic flow? This is my basic understanding:
PRU <-> mailbox <-> usr driver mapping HW FIFO to virtio(missing driver?) <-> usr code.
Is there a library for the PRU to use the HW Mailbox rx/tx queues?
Is it possible to open mailbox from userspace and send messages currently?

Right now, I'm using mmap from user space to PRU shared memory to query variables/state; this seems to be working.

0 Tim Michals over 10 years ago in reply to RonB

Intellectual 305 points

Status? For the generic kernel driver?

0 Jamie Maxwell over 10 years ago in reply to RonB

Expert 1530 points

Any update to this?

Basically I want a clean and simple and understandable way to load code to a PRU and then interact with that code in the PRU.
Remoteproc seems to be the way of the future but doesn’t seem complete yet.

Please advise.

I have been trying to follow through this tutorial in order to get something to work in a PRU. I haven’t been successful yet.

processors.wiki.ti.com/.../PRU_Training:_Hands-on_Labs

0 RonB over 10 years ago in reply to Jamie Maxwell

TI__Mastermind 30416 points

Jmax604,

I want that too :-). Unfortunately, as you indicate, it is not quite there yet. We are still trying to get something done in the next few weeks. Loading code with remoteproc should be fine, but interacting with it from Linux isn't complete. There is work to be done on both sides (firmware/LInux) to enable it.

The mmap method utilized by the the older PRUSS driver is currently the only option.

0 Tim Michals over 10 years ago in reply to RonB

Intellectual 305 points

Checking on the status on this, any progress?

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PRU RemoteProc communication initialization TI Kernel (3.14.26)