HDMI No Signal - Verdin iMX8M Mini with Dahlia Carrier

Technical Support
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1

Upon first booting the Verdin IMX8M Mini on a Dahlia carrier board according to the guide here: Unboxing and Setup Cables - Dahlia Carrier Board, we received no hdmi signal on our hdmi lcd panel. We tried two panels with no signal found for either. We followed the instructions verbatim, with the 12V 2A power plug, ethernet, USB-C debug, mouse, keyboard, and hdmi plugged in prior to boot.

The board lit up with 4 green lights next to the DSI to HDMI adapter, a temporary green light next to the RESET button, yellow and green lights next to the RECOVERY button, and the flashing yellow/green lights in ethernet modem plug.

Does anyone know if we missed something easy, or if this is a common issue?

Thank you.

2

Greetings @DVLevine,

Just to clarify, did you have HDMI output when first booting into Toradex Easy Installer as shown here: Installing the Operating System - Dahlia Carrier Board

Or did you not even install any software yet and there’s no output at all even with Easy Installer?

If it’s the case where you did install software and then HDMI output stopped working then if you installed any Linux 5.0 software it would be the case that the HDMI-DSI adapter needs to be reenabled. More details here: Display Output, Resolution and Timings (Linux) | Toradex Developer Center

This was a rather recent change which might explain why it doesn’t specify such in the quick start.

However if it’s the case where HDMI never worked even with Easy Installer then we’ll need more information.

  • What resolutions are your HDMI panels?
  • Have you tried a standard HDMI monitor/display instead of the panels?
  • Can you connect via serial over the USB debug? Is there any output when you power on the board?

Best Regards,
Jeremias

3

@jeremias.tx thank you for the response.

  1. I did not install any software yet and there is no output from the HDMI.
  2. I moved locations and do not have access to the original panels. But I did try 3 standard monitors: Acer X223W res. 1680x1050 (w/hdmi to dvi adapter) https://productz.com/en/acer-x223w/p/K7VNb. Acer 272HL res.1920x1080 (direct hdmi) https://www.acer.com/ac/en/US/content/model/UM.HT2AA.003, and an ASUS MB16AMT res. 1920x1080 (hdmi to mini hdmi) ZenScreen Touch MB16AMT｜Monitors｜ASUS USA. All did not appear to have any output, and remained in sleep mode while the system was powered. I believe I have connected to serial, because when I “connect” the debug lights go from yellow & green to only green. However, I do not see any output on the serial monitor when I power the board. I tested serial connecting via baudrates 9600, 38400, and 230400.

Thank you,
DVLevine

4

Assuming nothing is wrong with the hardware then by default all of our modules should be running Toradex Easy Installer as their initial software.

I find it troublesome that you’re not getting any HDMI output on multiple displays. I guess make sure the HDMI to DSI adapter is really connected properly.

Other than that let’s focus on getting serial output to make sure that the system is even booting properly. So first of all when referring to the USB-C debug you’re talking about X18 correct? Also the baud rate for our serial debug is “115200”. Finally for Verdin specifically when you connect the USB serial debug it can actually show up as 4 different USB devices. Typically the one you want to connect to for serial debug is the last one.

If you’ve confirmed all that and you are still not getting any serial output then you’ll need to try and put the system into recovery mode and then manually load the Easy Installer software that way. We describe this process here: Downloads & Installers | Toradex Developer Center

If even that doesn’t work then there’s possible some kind of hardware defect or fault at play here.

Best Regards,
Jeremias

5

@jeremias.tx : okay, so for serial on x18; picking the last serial monitor w/baudrate 115200 was a the right call. I made sure the HDMI-DSI adapter was fully screwed in. On boot I saw the following:

▒▒
U-Boot SPL 2018.03-toradex_imx_v2018.03_4.14.78_1.0.0_ga-bringup+gc0ff506c39 (Dec 31 2019 - 15:51:20 +0000)
power_bd71837_init
DDRINFO: start DRAM init
DRAM PHY training for 3000MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 400MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 100MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 3000MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC1


U-Boot 2018.03-toradex_imx_v2018.03_4.14.78_1.0.0_ga-bringup+gc0ff506c39 (Dec 31 2019 - 15:52:03 +0000)

CPU:   Freescale i.MX8MMQ rev1.0 1600 MHz (running at 1200 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 49C
Reset cause: POR
DRAM:  2 GiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
Loading Environment from MMC... OK
No panel detected: default to MIPI2HDMI
Display: MIPI2HDMI (1920x1080)
Video: 1920x1080x24
In:    serial
Out:   serial
Err:   serial
Model: Toradex Verdin iMX8M Mini 2GB Wi-Fi / BT IT V1.0B, Serial# 06612198

 BuildInfo:
  - ATF a-20190
  - U-Boot 2018.03-toradex_imx_v2018.03_4.14.78_1.0.0_ga-bringup+gc0ff506c39

flash target is MMC:0
Net:   No ethernet found.
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot:  0
MMC: no card present
switch to partitions #0, OK
mmc0(part 0) is current device
Scanning mmc 0:1...
Found U-Boot script /boot.scr
2225 bytes read in 14 ms (154.3 KiB/s)
## Executing script at 46000000
41774712 bytes read in 715 ms (55.7 MiB/s)
## Loading kernel from FIT Image at 43000000 ...
   Using 'config@1' configuration
   Trying 'kernel@1' kernel subimage
     Description:  Linux Kernel 4.14.159-2.0.4+gfff496c2a1bd
     Type:         Kernel Image
     Compression:  gzip compressed
     Data Start:   0x430000f8
     Data Size:    6675541 Bytes = 6.4 MiB
     Architecture: AArch64
     OS:           Linux
     Load Address: 0x80280000
     Entry Point:  0x80280000
     Hash algo:    md5
     Hash value:   db8671f6273f270e4a59ac62afd5dd28
   Verifying Hash Integrity ... md5+ OK
## Loading ramdisk from FIT Image at 43000000 ...
   Using 'config@1' configuration
   Trying 'ramdisk@1' ramdisk subimage
     Description:  SquashFS RAMdisk
     Type:         RAMDisk Image
     Compression:  uncompressed
     Data Start:   0x4365de3c
     Data Size:    35053568 Bytes = 33.4 MiB
     Architecture: AArch64
     OS:           Linux
     Load Address: 0xa0000000
     Entry Point:  unavailable
     Hash algo:    md5
     Hash value:   87958cac366f6cbb5ec542d686010a48
   Verifying Hash Integrity ... md5+ OK
   Loading ramdisk from 0x4365de3c to 0xa0000000
## Loading fdt from FIT Image at 43000000 ...
   Using 'config@1' configuration
   Trying 'fdt@1' fdt subimage
     Description:  Verdin iMX8iMM Device Tree
     Type:         Flat Device Tree
     Compression:  uncompressed
     Data Start:   0x457cbf1c
     Data Size:    43538 Bytes = 42.5 KiB
     Architecture: AArch64
     Hash algo:    md5
     Hash value:   5509d2974ce87fd8e93218b11b5a5bbc
   Verifying Hash Integrity ... md5+ OK
   Booting using the fdt blob at 0x457cbf1c
   Uncompressing Kernel Image ... OK
   Loading Device Tree to 00000000bd716000, end 00000000bd723a11 ... OK

Starting kernel ...

[    0.184588] pca953x 3-0021: failed reading register
[    0.185854] dmi: Firmware registration failed.
[    1.978091] caam-snvs 30370000.caam-snvs: can't get snvs clock
[    2.175474] imx6q-pcie 33800000.pcie: Speed change timeout
Running /etc/rc.local...
TDX_VER_ID="Verdin-iMX8MM_ToradexEasyInstaller_2.0b4-20191231"
Starting udev
System time was Wed Nov 18 15:16:32 UTC 2020.
Setting the System Clock using the Hardware Clock as reference...
System Clock set. System local time is now Wed Nov 18 15:16:32 UTC 2020.

Welcome to the Toradex Easy Installer

This is a Linux based installer for Toradex modules. Currently, the installer
does not have a serial console interface. You can use the Toradex Easy Installer
via any of the available display interfaces using USB mouse/keyboard or via a
network connection using VNC. Use:
  # ip addr show eth0
to display the Ethernet IP address or use USB RNDIS at IP 192.168.11.1.

Check our documentation at:
  https://developer.toradex.com/software/toradex-easy-installer
/ #
6

@jeremias.tx
I checked the DSI to HDMI converter - it appears to be seated well. The surrounding screws are tight.

Following your advice, x18 on the final serial port with baudrate 115200 yielded a debug feed. Still no HDMI signal, but log follows below.

▒▒
U-Boot SPL 2018.03-toradex_imx_v2018.03_4.14.78_1.0.0_ga-bringup+gc0ff506c39 (Dec 31 2019 - 15:51:20 +0000)
power_bd71837_init
DDRINFO: start DRAM init
DRAM PHY training for 3000MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 400MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 100MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 3000MTS
check ddr_pmu_train_imem code
check ddr_pmu_train_imem code pass
check ddr_pmu_train_dmem code
check ddr_pmu_train_dmem code pass
Training PASS
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC1


U-Boot 2018.03-toradex_imx_v2018.03_4.14.78_1.0.0_ga-bringup+gc0ff506c39 (Dec 31 2019 - 15:52:03 +0000)

CPU:   Freescale i.MX8MMQ rev1.0 1600 MHz (running at 1200 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 49C
Reset cause: POR
DRAM:  2 GiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
Loading Environment from MMC... OK
No panel detected: default to MIPI2HDMI
Display: MIPI2HDMI (1920x1080)
Video: 1920x1080x24
In:    serial
Out:   serial
Err:   serial
Model: Toradex Verdin iMX8M Mini 2GB Wi-Fi / BT IT V1.0B, Serial# 06612198

 BuildInfo:
  - ATF a-20190
  - U-Boot 2018.03-toradex_imx_v2018.03_4.14.78_1.0.0_ga-bringup+gc0ff506c39

flash target is MMC:0
Net:   No ethernet found.
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot:  0
MMC: no card present
switch to partitions #0, OK
mmc0(part 0) is current device
Scanning mmc 0:1...
Found U-Boot script /boot.scr
2225 bytes read in 14 ms (154.3 KiB/s)
## Executing script at 46000000
41774712 bytes read in 715 ms (55.7 MiB/s)
## Loading kernel from FIT Image at 43000000 ...
   Using 'config@1' configuration
   Trying 'kernel@1' kernel subimage
     Description:  Linux Kernel 4.14.159-2.0.4+gfff496c2a1bd
     Type:         Kernel Image
     Compression:  gzip compressed
     Data Start:   0x430000f8
     Data Size:    6675541 Bytes = 6.4 MiB
     Architecture: AArch64
     OS:           Linux
     Load Address: 0x80280000
     Entry Point:  0x80280000
     Hash algo:    md5
     Hash value:   db8671f6273f270e4a59ac62afd5dd28
   Verifying Hash Integrity ... md5+ OK
## Loading ramdisk from FIT Image at 43000000 ...
   Using 'config@1' configuration
   Trying 'ramdisk@1' ramdisk subimage
     Description:  SquashFS RAMdisk
     Type:         RAMDisk Image
     Compression:  uncompressed
     Data Start:   0x4365de3c
     Data Size:    35053568 Bytes = 33.4 MiB
     Architecture: AArch64
     OS:           Linux
     Load Address: 0xa0000000
     Entry Point:  unavailable
     Hash algo:    md5
     Hash value:   87958cac366f6cbb5ec542d686010a48
   Verifying Hash Integrity ... md5+ OK
   Loading ramdisk from 0x4365de3c to 0xa0000000
## Loading fdt from FIT Image at 43000000 ...
   Using 'config@1' configuration
   Trying 'fdt@1' fdt subimage
     Description:  Verdin iMX8iMM Device Tree
     Type:         Flat Device Tree
     Compression:  uncompressed
     Data Start:   0x457cbf1c
     Data Size:    43538 Bytes = 42.5 KiB
     Architecture: AArch64
     Hash algo:    md5
     Hash value:   5509d2974ce87fd8e93218b11b5a5bbc
   Verifying Hash Integrity ... md5+ OK
   Booting using the fdt blob at 0x457cbf1c
   Uncompressing Kernel Image ... OK
   Loading Device Tree to 00000000bd716000, end 00000000bd723a11 ... OK

Starting kernel ...

[    0.184588] pca953x 3-0021: failed reading register
[    0.185854] dmi: Firmware registration failed.
[    1.978091] caam-snvs 30370000.caam-snvs: can't get snvs clock
[    2.175474] imx6q-pcie 33800000.pcie: Speed change timeout
Running /etc/rc.local...
TDX_VER_ID="Verdin-iMX8MM_ToradexEasyInstaller_2.0b4-20191231"
Starting udev
System time was Wed Nov 18 15:16:32 UTC 2020.
Setting the System Clock using the Hardware Clock as reference...
System Clock set. System local time is now Wed Nov 18 15:16:32 UTC 2020.

Welcome to the Toradex Easy Installer

This is a Linux based installer for Toradex modules. Currently, the installer
does not have a serial console interface. You can use the Toradex Easy Installer
via any of the available display interfaces using USB mouse/keyboard or via a
network connection using VNC. Use:
  # ip addr show eth0
to display the Ethernet IP address or use USB RNDIS at IP 192.168.11.1.

Check our documentation at:
  https://developer.toradex.com/software/toradex-easy-installer
/ #
7

Alright then from the serial output it definitely seems like your device is at least booting properly and it’s just an issue with the HDMI output. Let’s try this then, your device is running Toradex Easy Installer as it should be far as I can tell. You should be able to access the Installer UI via some VNC viewer program as detailed here: Downloads & Installers | Toradex Developer Center

Try accessing the UI from your development PC then install one of the software listed. Let me know whether the HDMI issues persists after you install one of the other software. This will help narrow down whether this is just an issue with the Easy Installer or whether it’s more systematic.

As a side note if you install any of the version 5.0 software from us the support for the DSI-HDMI adapter needs to be re-enabled after installing. More details on this here: Display Output, Resolution and Timings (Linux) | Toradex Developer Center

Best Regards,
Jeremias

8

@jeremias.tx

Some success and another question

  1. Installation Success: Remote VNC via USB RNDIS on USB OTG port X3 worked at 192.168.11.1, and I was able to install Torizon Core 5.1 with evaluation containers.
  2. Enabling HDMI Question: Assuming the DSI to HDMI is not physically broken, to reenable the DSI-HDMI support I tried to follow the instructions you posted. However, after sshing using user “torizon”, I could not locate “/media/mmcblk0p1/overlays.txt.” ‘/media/mmcblk0p1’ did not show up for me as a file or directory. Inside /media, the only directory I see inside /media is BOOT, and inside BOOT, the only file is boot.scr. Am I missing something?

Thank you very much for your help thus far!
DVLevine

9

Ah if you installed Torizon the overlay process is actually different than in our non-Torizon BSP. So for Torizon the method is a little more involved due to filesystem structure differences but it is described in detail here: Device Tree Overlays on Torizon | Toradex Developer Center

Best Regards,
Jeremias