RPMSG on a Toradex Apalis iMX8qm

[tak]

Dear Toradex Community,

I am building an application on Apalis iMX8qm for M4 communication I2C to A core linux. I am testing the demo rpms_lite_pingpong_rtos_linux_remote_m41 to the communication link between two MCU platform. However, I cannot get the imx_rpmsg_pingpong device in /dev.

The following is the details of my testing platform

• Hardware: Apalis iMX8 QuadMax 4GB Wi-Fi / Bluetooth IT
• Carrier board: Ixora v1.2
• Linux apalis-imx8-07278385 5.4.193-5.7.2+git.b60d3160fd04 (remote download from Toradex Embedded Linux Reference Multimedia Image by Easy Installer)

This is the source of my dtbo file:

/dts-v1/;
/plugin/;

/* Disable PWM0 and PMW1 to use M4 Core 1 UART */

/ {

	compatible = "toradex,apalis-imx8-v1.1-eval",
		     "toradex,apalis-imx8-eval",
		     "toradex,apalis-imx8",
		     "fsl,imx8qm";
};

&pwm0 {
    status = "disabled";
};

&pwm1 {
    status = "disabled";
};	
  
&lpuart2 {
    status = "disabled";
};

&rpmsg1{
	status = "okay";
};

I checked the booting message when the system bootup. Some problem is happening in memory map. The error message has been shown as follows:

[    3.206548] imx-rpmsg 90100000.rpmsg1: assigned reserved memory node vdevbuffer
[    3.213977] ------------[ cut here ]------------
[    3.218611] WARNING: CPU: 4 PID: 99 at arch/arm64/mm/ioremap.c:47 __ioremap_caller+0xbc/0xe0
[    3.227050] Modules linked in:
[    3.230110] CPU: 4 PID: 99 Comm: kworker/4:1 Not tainted 5.4.193-5.7.2+git.b60d3160fd04 #1
[    3.238379] Hardware name: Toradex Apalis iMX8QM V1.1 on Apalis Evaluation Board (DT)
[    3.246223] Workqueue: events deferred_probe_work_func
[    3.251369] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    3.256160] pc : __ioremap_caller+0xbc/0xe0
[    3.260349] lr : __ioremap_caller+0x50/0xe0
[    3.264532] sp : ffff800011d5b740
[    3.267842] x29: ffff800011d5b740 x28: ffff0008785c1400 
[    3.273159] x27: 0000000000000000 x26: ffff000874304880 
[    3.278476] x25: 0000000000000000 x24: ffff0008741fe730 
[    3.283793] x23: 0068000000000707 x22: ffff800010bdd070 
[    3.289110] x21: 0000000000000000 x20: 0000000090100000 
[    3.294426] x19: 0000000000003000 x18: 0000000000000000 
[    3.299743] x17: 000000000e010cbc x16: 000000000e011cbc 
[    3.305060] x15: ffff0008781d59f0 x14: ffffffffffffffff 
[    3.310368] x13: ffff0008742ff91c x12: 0000000000000030 
[    3.315685] x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f 
[    3.321001] x9 : 0000000000000000 x8 : 0000000000200000 
[    3.326318] x7 : 0000000000000018 x6 : ffff800011949748 
[    3.331635] x5 : ffff800011949718 x4 : 0000000000000003 
[    3.336951] x3 : 0000000000000003 x2 : 0000000090200000 
[    3.342268] x1 : 0000000000000002 x0 : 0000000000000001 
[    3.347590] Call trace:
[    3.350039]  __ioremap_caller+0xbc/0xe0
[    3.353879]  __ioremap+0x14/0x20
[    3.357116]  imx_rpmsg_find_vqs+0xd8/0x2a8
[    3.361209]  rpmsg_probe+0xdc/0x370
[    3.364704]  virtio_dev_probe+0x19c/0x238
[    3.368715]  really_probe+0xd8/0x438
[    3.372285]  driver_probe_device+0xdc/0x130
[    3.376472]  __device_attach_driver+0x88/0x108
[    3.380920]  bus_for_each_drv+0x74/0xc8
[    3.384760]  __device_attach+0xec/0x170
[    3.388592]  device_initial_probe+0x10/0x18
[    3.392779]  bus_probe_device+0x90/0x98
[    3.396618]  device_add+0x3a4/0x688
[    3.400104]  register_virtio_device+0xb4/0x110
[    3.404551]  imx_rpmsg_probe+0x230/0x520
[    3.408479]  platform_drv_probe+0x50/0xa0
[    3.412491]  really_probe+0xd8/0x438
[    3.416061]  driver_probe_device+0xdc/0x130
[    3.420249]  __device_attach_driver+0x88/0x108
[    3.423544] usb 3-1: new high-speed USB device number 2 using ci_hdrc
[    3.424696]  bus_for_each_drv+0x74/0xc8
[    3.424704]  __device_attach+0xec/0x170
[    3.438823]  device_initial_probe+0x10/0x18
[    3.443001]  bus_probe_device+0x90/0x98
[    3.446832]  deferred_probe_work_func+0x80/0xd0
[    3.451360]  process_one_work+0x1b4/0x328
[    3.455372]  worker_thread+0x1f0/0x420
[    3.459116]  kthread+0x138/0x158
[    3.462341]  ret_from_fork+0x10/0x1c
[    3.465918] ---[ end trace 539575572e3d4fc2 ]---
[    3.470573] virtio_rpmsg_bus: probe of virtio0 failed with error -12

I found a similar problem was happened in iMX8MP platform and I have checked this link

RPMSG does not work on IMX8M-Plus

Hi everyone, I’m going down the rabbit hole and trying to debug the driver (virtio_rpmsg_bus.c) through dev_dbg and try to find out what exactly is failing/returning.

but I cannot success in my iMX8qm board yet.

May I ask anyone can help if anyone success running rpmsg on iMX8qm platform and can teach me know to do it?

Thanks a lot.

Best regards,

Tak

[hfranco.tx]

Hi @tak,

For Apalis iMX8 Downstream kernel version 5.4, you need to use the following code in your overlay:

RPMSG on a Toradex Apalis iMX8

Hi @Juli7478, I’m sorry for the delay. For TorizonCore 5 or BSP 5, can you please try the following code? /dts-v1/; /plugin/; #include <dt-bindings/firmware/imx/rsrc.h> /* Enable RPMSG for Apalis iMX8 */ / { compatible = "toradex,apalis-imx8-v1.1", "toradex,apalis-imx8", "fsl,imx8qm"; }; &{/} { reserved-memory { #address-cells = <2>; #size-cells = <2>; ranges; /* Allocate TX and RX buffers for communication between m4 cores with Linux and m4 co…

Also, you can find the compiled DTBO file in this comment:

RPMSG on a Toradex Apalis iMX8

Hi @Juli7478, I tested the overlay on my side with TorizonCore 5 and it worked for me. Could you please double-check how you’re loading it? If you want to try mine, here is the DTBO file (it’s going to be available for 3 months): Download - Toradex File Sharing Platform Here I copied this file to /boot/ostree/<hash>/dtb/overlays and then edited the /boot/ostree/<hash>/dtb/overlays.txt file to include the name of this overlay, apalis-imx8_hmp_overlay.dtbo. Next, I’ve compiled and loaded the M…

The file will be available for 3 months.

This thread should help you set everything up. Please, let me know here if you have any questions about it.

Best Regards,
Hiago.

[tak]

Dear Juli,

Thank you very much for your help. Here is my update. I found that the binary (Toradex Embedded Linux Reference Multimedia Image 5.7.2+build.21) which is downloaded from Easy Installer (cloud) calls imx8qm-apalis-v1.1-eval.dtb as the device tree blob. Then I tried to reverse it by dtc and I found a little bit strange thing. In the reserved-memory section, I found the reg called 0x90200000 instead of 0x90000000 for rpmsg@0x0x90000000 section. I guess it may be the problem of memory crash.

reserved-memory {
	#address-cells = <0x02>;
	#size-cells = <0x02>;
	ranges;
            :
            :
	rpmsg@0x90000000 {
		no-map;
		reg = <0x00 0x90200000 0x00 0x200000>;
		phandle = <0x247>;
	};
            :
            :

When I changed the reg to 0x90000000, the pingpong looks like to work.

	rpmsg@0x90000000 {
		no-map;
		reg = <0x00 0x90000000 0x00 0x200000>;
		phandle = <0x247>;
	};

I will also try your dtbo as well. Thanks a lot for your help.

By the way, may I ask one more question? When I use 6.2.0+build from the cloud, I found that if I add the disable code in overlay file as below. The linux prompted device tree flatten error and cannot be booted up. However, the same dtbo works find in 5.7.22+build. May I ask whether you have any idea about this?

&pwm0 {
status = “disabled”;
};

&pwm1 {
status = “disabled”;
};

Many thanks again for your help.

Best regards,

Tak

[josep.tx]

Hello @tak ,

@tak

By the way, may I ask one more question? When I use 6.2.0+build from the cloud, I found that if I add the disable code in overlay file as below. The linux prompted device tree flatten error and cannot be booted up. However, the same dtbo works find in 5.7.22+build. May I ask whether you have any idea about this?

&pwm0 {
status = “disabled”;
};

&pwm1 {
status = “disabled”;
};

Many thanks again for your help.

Best regards,

Tak

For this question I would ask you to open another topic, so we have 1 topic → 1 question. Thanks

P.S. If the original question in this topic is solved, please mark the suitable answer as solution.

Best regards,
Josep