RPMSG - Kernel 4.14 - weird characters on the m4 side

Hi,

I create my sumo-imx7d-Yocto image with this:

repo init -u GitHub - TechNexion/tn-imx-yocto-manifest: TechNexion i.MX Yocto manifests -b sumo_4.14.y_GA-stable -m imx-4.14.98-2.0.1_patch.xml
repo sync -j8
DISTRO=fsl-imx-x11 MACHINE=pico-imx7 BASEBOARD=pi source edm-setup-release.sh -b build-x11-pico-imx7
bitbake core-image-base

Then I go to:

I transfer rpmsg_str_echo_freertos_example.bin to U-boot partition.

In U-boot this work OK. But in linux, I have weird characters on the m4 side (look pic)

stty results commands: (Look to 38400 to ttyRPMSG0)

root@pico-imx7:/# stty -F /dev/ttyRPMSG0
speed 38400 baud; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = ;
eol2 = ; swtch = ; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-brkint -imaxbel

stty -F /dev/ttymxc4
speed 115200 baud; line = 0;
intr = ^C; quit = ^; erase = ^?; kill = ^U; eof = ^D; eol = ;
eol2 = ; swtch = ; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-brkint ixoff -imaxbel iutf8
-iexten

When I do echo hello > /dev/ttyRPMSG0
(before ls /dev/tty* result=/dev/ttyRPMSG0) I get=���类�&a����}���w������v�
In m4 side

How to solve it? (pls)



Not related to Toradex hardware. Please get in touch with Hardware Manufacturer for support.

Also feel free to check and move to Toradex products: NXP i.MX 7 - Arm Computer/System on Module (toradex.com)

Greetings