am62xx-evm login: root
root@am62xx-evm:~# uname -a
Linux am62xx-evm 6.6.58-rt45-ti-rt-01780-gc79d7ef3a56f-dirty #1 SMP PREEMPT_RT Wed Nov 27 14:15:26 UTC 2024 aarch64 GNU/Linux

// remoteprocX association can change each boot
// that means you should check the name to figure out which
// remoteprocX is associated with which core
root@am62xx-evm:~# head /sys/class/remoteproc/remoteproc*/name
==> /sys/class/remoteproc/remoteproc0/name <==
5000000.m4fss

==> /sys/class/remoteproc/remoteproc1/name <==
78000000.r5f

==> /sys/class/remoteproc/remoteproc2/name <==
30074000.pru

==> /sys/class/remoteproc/remoteproc3/name <==
30078000.pru

// what happened during Linux boot?
root@am62xx-evm:~# dmesg | grep remoteproc
[   21.556333] k3-m4-rproc 5000000.m4fss: configured M4 for remoteproc mode
[   21.562085] remoteproc remoteproc0: 5000000.m4fss is available
[   21.578014] remoteproc remoteproc0: powering up 5000000.m4fss
[   21.578052] remoteproc remoteproc0: Booting fw image am62-mcu-m4f0_0-fw, size 55100
[   21.601408] remoteproc remoteproc0: remote processor 5000000.m4fss is now up
[   21.807209] remoteproc remoteproc1: 78000000.r5f is available
[   21.807354] remoteproc remoteproc1: attaching to 78000000.r5f
[   21.825583] remoteproc remoteproc1: remote processor 78000000.r5f is now attached
[   22.512695] remoteproc remoteproc2: 30074000.pru is available
[   22.525854] remoteproc remoteproc3: 30078000.pru is available

// we expect the cores to be off based on the Linux boot. Is that true?
root@am62xx-evm:~# cat /sys/class/remoteproc/remoteproc2/state
offline
root@am62xx-evm:~# cat /sys/class/remoteproc/remoteproc3/state
offline

// is the RPMsg firmware on the filesystem?
root@am62xx-evm:~# ls /lib/firmware/pru/PRU_
PRU_Halt.out                   PRU_RPMsg_Echo_Interrupt0.out  PRU_RPMsg_Echo_Interrupt1.out

// is the remoteproc firmware already pointing to the RPMsg example?
root@am62xx-evm:~# cat /sys/class/remoteproc/remoteproc2/firmware
am62x-pru0-fw
root@am62xx-evm:~# cat /sys/class/remoteproc/remoteproc3/firmware
am62x-pru1-fw

root@am62xx-evm:~# ls -al /lib/firmware/
total 25460
drwxr-xr-x  6 root root    4096 Mar  9  2018 .
drwxr-xr-x 81 root root   61440 Mar  9  2018 ..
-rw-r--r--  1 root root    2040 Mar  9  2018 LICENCE.ibt_firmware
-rw-r--r--  1 root root    2046 Mar  9  2018 LICENCE.iwlwifi_firmware
lrwxrwxrwx  1 root root      72 Mar  9  2018 am62-mcu-m4f0_0-fw -> /usr/lib/firmware/ti-ipc/am62xx/ipc_echo_test_mcu2_0_release_strip.xer5f
lrwxrwxrwx  1 root root      79 Mar  9  2018 am62-mcu-m4f0_0-fw-sec -> /usr/lib/firmware/ti-ipc/am62xx/ipc_echo_test_mcu2_0_release_strip.xer5f.signed
lrwxrwxrwx  1 root root      51 Mar  9  2018 am62x-pru0-fw -> /usr/lib/firmware/pru/PRU_RPMsg_Echo_Interrupt0.out
lrwxrwxrwx  1 root root      51 Mar  9  2018 am62x-pru1-fw -> /usr/lib/firmware/pru/PRU_RPMsg_Echo_Interrupt1.out
..

// start the PRU cores
root@am62xx-evm:~# echo start > /sys/class/remoteproc/remoteproc2/state
[ 4875.923209] remoteproc remoteproc2: powering up 30074000.pru
[ 4875.926398] remoteproc remoteproc2: Booting fw image am62x-pru0-fw, size 81504
[ 4875.945016] virtio_rpmsg_bus virtio2: rpmsg host is online
[ 4875.945063] virtio_rpmsg_bus virtio2: creating channel rpmsg-pru addr 0x1e
[ 4875.945337] rproc-virtio rproc-virtio.5.auto: registered virtio2 (type 7)
[ 4875.945351] remoteproc remoteproc2: remote processor 30074000.pru is now up
[ 4875.964989] rpmsg_pru virtio2.rpmsg-pru.-1.30: new rpmsg_pru device: /dev/rpmsg_pru30
root@am62xx-evm:~# echo start > /sys/class/remoteproc/remoteproc3/state
[ 4880.992188] remoteproc remoteproc3: powering up 30078000.pru
[ 4880.995432] remoteproc remoteproc3: Booting fw image am62x-pru1-fw, size 81504
[ 4881.014935] virtio_rpmsg_bus virtio3: rpmsg host is online
[ 4881.014978] virtio_rpmsg_bus virtio3: creating channel rpmsg-pru addr 0x1f
[ 4881.015195] rproc-virtio rproc-virtio.6.auto: registered virtio3 (type 7)
[ 4881.015209] remoteproc remoteproc3: remote processor 30078000.pru is now up
[ 4881.015821] rpmsg_pru virtio3.rpmsg-pru.-1.31: new rpmsg_pru device: /dev/rpmsg_pru31

// run the test
root@am62xx-evm:~# ls /dev/ | grep pru
rpmsg_pru30
rpmsg_pru31
root@am62xx-evm:~# echo "test1" > /dev/rpmsg_pru30
root@am62xx-evm:~# echo "test2" > /dev/rpmsg_pru31
root@am62xx-evm:~# cat /dev/rpmsg_pru30
test1
^C
root@am62xx-evm:~# cat /dev/rpmsg_pru31
test2
^C

此致、

Nick