VIA Technologies SOM-9X35-STK User manual

QUICK START GUIDE
VIA SOM-9X35-STK
Yocto 3.1 EVK
1.00-30032022

Copyright
Copyright © 2022 VIA Technologies Incorporated. All rights reserved.
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VIA Technologies makes no warranes, implied or otherwise, in regard to this document and to the products described in this document.
The informaon provided in this document is believed to be accurate and reliable as of the publicaon date of this document. However,
VIA Technologies assumes no responsibility for the use or misuse of the informaon (including use or connecon of extra device/
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and product specicaons within this document are subject to change at any me, without noce and without obligaon to nofy any
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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
Revision History
Version Date Remarks
1.00 30/03/2022 Inial release

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
Table of Contents
1. Introducon.................................................................................................................................................... 1
1.1 EVK Package Contents........................................................................................................................... 1
1.1.1 Firmware Folder Contents ............................................................................................................. 1
1.1.2 Document Folder Contents............................................................................................................ 1
1.1.3 Tool Folder Contents...................................................................................................................... 1
1.2 Version Informaon and Supported Features....................................................................................... 2
2. Image Installaon .......................................................................................................................................... 3
2.1 Installing with the Fastboot Mode ........................................................................................................ 3
3. Hardware Funcons ....................................................................................................................................... 5
3.1 Using the Debug Console...................................................................................................................... 5
3.2 Changing the Kernel Debug Level ......................................................................................................... 6
3.3 Checking the BSP Version...................................................................................................................... 6
3.4 DVFS...................................................................................................................................................... 7
3.5 Display................................................................................................................................................... 7
3.6 Video playback...................................................................................................................................... 7
3.7 Audio Output and Record ..................................................................................................................... 8
3.8 Camera.................................................................................................................................................. 9
3.9 Wi-Fi...................................................................................................................................................... 9
3.10 Bluetooth ............................................................................................................................................ 10

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
1. Introducon
This Quick Start Guide provides an overview of how to boot the Yocto image for the VIA SOM-9X35-STK and
congure the supported hardware funcons in the build.
Note:
The VIA SOM-9X35-STK includes the VIA SOM-9X35 module and the VIA VAB-935 reference carrier board.
The VIA SOM-9X35-STK Yocto 3.1 EVK is developed based on the MediaTek Yocto 3.1 BSP, and it enables the
hardware features of the VIA SOM-9X35-STK.
1.1 EVK Package Contents
There are three folders in the package listed as below.
Firmware folder Descripon
VIA_SOM-9X35-STK_Yocto_3.1_EVK.zip Yocto image
Document folder Descripon
VIA_SOM-9X35-STK_Yocto_3.1_EVK_Quick_Start_Guide.pdf Quick Start Guide
Tool folder Descripon
VIA_Android_USB_Driver.zip VIA USB driver
1.1.1 Firmware Folder Contents
VIA_SOM-9X35-STK_Yocto_3.1_EVK.zip: Contains the precompiled Yocto image for evaluang the VIA SOM-
9X35-STK.
1.1.2 Document Folder Contents
VIA_SOM-9X35-STK_Yocto_3.1_EVK_Quick_Start_Guide.pdf: This Quick Start Guide provides an overview on
how to boot the Yocto image for the VIA SOM-9X35-STK and congure the supported hardware funcons in the
build.
1.1.3 Tool Folder Contents
VIA_Android_USB_Driver.zip: VIA USB driver.

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
1.2 Version Informaon and Supported Features
• Kernel version: 4.14.87
• Evaluaon image: Yocto 3.1
• Development based on MediaTek Yocto 3.1 BSP
• Supports eMMC boot
• Supports HDMI display
• Supports HDMI audio output
• Supports MIPI DSI capacive touch panel
−ShenZhen K&D 7" KD070D54-39NH-B018-A (1024x600)
−Silead GSL1680 I2C touch
• Supports COM port as RS-232 mode (TX/RX)
• Supports 10/100Mbps Ethernet port
• Supports MediaTek MT6357 Line-out and Mic-in
• Supports MediaTek MT6631 Wi-Fi 802.11ac and Bluetooth 5.0
• Supports VIA EMIO-2573 (EC25) 4G LTE mobile broadband miniPCIe module
• Supports MIPI CSI IMX135 camera module
• Supports MediaTek NeuroPilot AI APU hardware acceleraon

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
2. Image Installaon
This secon explains the setup requirements for boong from the eMMC.
The precompiled images are provided in the "Firmware" folder.
2.1 Installing with the Fastboot Mode
The rst step is to prepare the "fastboot tool" and install the "VIA USB driver" into your Windows 10 host
machine.
To get the "fastboot tool" for Windows, please refer to the "SDK Plaorm Tools release notes" chapter on the
Android developer website (hps://developer.android.com/studio/releases/plaorm-tools).
To install the "VIA USB driver", right-click on the mouse buon to install the "android_winusb". When nished,
it will show "The operaon completed successfully".
Then connect the Windows 10 host machine and the VIA SOM-9X35-STK through the Micro USB 2.0 port using
the Micro USB cable.
Micro USB
Micro USB 2.0 port diagram
Plug in the AC-to-DC power adapter to power on the VIA SOM-9X35-STK.
The VIA SOM-9X35-STK will stop at "fastboot: processing commands" as shown in the debug console below.
Fastboot Mode
Note:
Make sure the Windows 10 host machine detects the VIA SOM-9X35-STK as an Android device.
Extract the VIA_SOM-9X35-STK_Yocto_3.1_EVK.zip les on your Windows 10 host machine.
To install the image, use the following command:
D:\VIA_SOM-9X35-STK_Yocto_3.1_EVK>set PATH=D:\platform-tools;%PATH%
D:\VIA_SOM-9X35-STK_Yocto_3.1_EVK>viaash.exe --yocto
VIA: Operating system is Yocto
VIA: erasing preloader partition
VIA: installing bl2.img
VIA: installing MBR_EMMC
VIA: installing tee.img
VIA: erasing tee_b partition
VIA: installing boot.img
VIA: erasing boot_b partition
VIA: installing system.img
VIA: erasing system_b partition
VIA: installing userdata.ext4
VIA: rebooting target system
D:\VIA_SOM-9X35-STK_Yocto_3.1_EVK>

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
If you have already installed the image, use the following command to enter the Fastboot Mode on your
Windows 10 host machine.
D:\platform-tools>adb reboot bootloader
Unplug the AC-to-DC power adapter to power o the VIA SOM-9X35-STK.
Unplug the Micro USB cable, press the Power Buon for 2 seconds, then release it to power on the VIA SOM-
9X35-STK.
When the boot process has completed, you will see the Yocto 3.1 desktop.

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
3. Hardware Funcons
This secon explains how to enable and test the hardware funcons precompiled in the Yocto 3.1 EVK including
using the debug console.
3.1 Using the Debug Console
Insert one plug connector of the 4-pin FFC cable into the J3 port labeled "UART0" on the VIA SOM-9X35
module, ensuring that the gold nger of the FFC cable faces down.
UART0 Port
Insert the other plug connector of the 4-pin FFC cable into the 4-pin FFC port located on the USB to UART
debug board, ensuring that the gold nger of the FFC cable faces down.

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
FCC Port
Connect the Windows 10 host machine through the Micro USB 2.0 port on the USB to UART debug board using
the Micro USB cable.
Use a serial port communicaon program such as PuTTY or Tera Term to connect the debug console. Set the
console Baud Rate to "921600".
Next, power on the VIA SOM-9X35-STK to iniate the boot process.
When the boot process has completed, log in to the debug console. The default account is "username: root /
password: root"
3.2 Changing the Kernel Debug Level
To disable the kernel messages, modify the debug level using the following command:
root@aiv8365m1v1-aiot-emmc:~# echo 3 > /proc/sys/kernel/printk
3.3 Checking the BSP Version
To check the BSP version, use the following command:
root@aiv8365m1v1-aiot-emmc:~# cat /proc/version

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
3.4 DVFS
To verify the DVFS (Dynamic Voltage Frequency Scaling) funcon and list all the supported features, use the
following commands:
root@aiv8365m1v1-aiot-emmc:~# ls -al /sys/devices/system/cpu/cpu0/cpufreq/
total 0
drwxr-xr-x 4 root root 0 Aug 26 11:15 .
drwxr-xr-x 3 root root 0 Aug 26 11:15 ..
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 aected_cpus
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 cpuinfo_cur_freq
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 cpuinfo_max_freq
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 cpuinfo_min_freq
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 cpuinfo_transition_latency
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 related_cpus
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_available_frequencies
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_available_governors
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_cur_freq
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_driver
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_governor
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_max_freq
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_min_freq
-rwxr-xr-x 1 root root 4096 Aug 26 11:15 scaling_setspeed
drwxr-xr-x 2 root root 0 Aug 26 11:15 schedutil
drwxr-xr-x 2 root root 0 Aug 26 11:15 stats
To check the supported and current CPU frequency, use the following commands:
:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
850000 918000 987000 1056000 1125000 1216000 1308000 1400000 1466000 1533000 1633000 1700000
1767000 1834000 1917000 2001000
:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
1308000
3.5 Display
There is no need to set the display device. If you connect an HDMI display, HDMI output will be automacally
enabled aer boong. If you connect an LCD panel, LCD panel output will be automacally enabled aer
boong.
To control the LCD backlight, use the following commands:
root@aiv8365m1v1-aiot-emmc:~# cd /sys/devices/platform/backlight_lcd0/backlight/backlight_
lcd0/
root@aiv8365m1v1-aiot-emmc:~# cat max_brightness
16
root@aiv8365m1v1-aiot-emmc:~# echo 16 > brightness
Note:
There are only 17 (0~16) levels for the LCD backlight control.
3.6 Video playback
The VIA SOM-9X35-STK supports H.265 and H.264 video decoding up to 1080p@60fps/40Mbps.
To playback video, use the following command:
root@aiv8365m1v1-aiot-emmc:~# gst-launch-1.0 -q playbin uri=le:/data/sda1/test.
mp4 ags=0x42 video-sink="mtkmdp width=640 height=480 ! video/x-raw,format=I420 !
mtkwaylandsink" audio-sink="autoaudiosink"

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
3.7 Audio Output and Record
To set up the HDMI audio output, use the following command:
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='O00 I05 Switch' 1
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='O01 I06 Switch' 1
root@aiv8365m1v1-aiot-emmc:~# aplay /data/sda1/test.wav
To disable the HDMI audio output, use the following command:
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='O00 I05 Switch' 0
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='O01 I06 Switch' 0
To set up the headphone and the speaker audio output, use the following command:
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='Audio_Amp_R_Switch' 1
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='Audio_Amp_L_Switch' 1
root@aiv8365m1v1-aiot-emmc:~# aplay /data/sda1/test.wav
To disable the headphone and the speaker audio output, use the following command:
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='Audio_Amp_R_Switch' 0
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='Audio_Amp_L_Switch' 0
Note:
Before changing to dierent audio output device, you must make sure the previous audio output device is disabled.
To change the audio volume, use the following command:
root@aiv8365m1v1-aiot-emmc:~# amixer -c0 cset name='Headset_PGAR_GAIN' 30
numid=35,iface=MIXER,name='Headset_PGAR_GAIN'
; type=ENUMERATED,access=rw------,values=1,items=32
; Item #0 '8Db'
; Item #1 '7Db'
; Item #2 '6Db'
; Item #3 '5Db'
; Item #4 '4Db'
; Item #5 '3Db'
; Item #6 '2Db'
; Item #7 '1Db'
; Item #8 '0Db'
; Item #9 '-1Db'
; Item #10 '-2Db'
; Item #11 '-3Db'
; Item #12 '-4Db'
; Item #13 '-5Db'
; Item #14 '-6Db'
; Item #15 '-7Db'
; Item #16 '-8Db'
; Item #17 '-9Db'
; Item #18 '-10Db'
; Item #19 '-11Db'
; Item #20 '-12Db'
; Item #21 '-13Db'
; Item #22 '-14Db'
; Item #23 '-15Db'
; Item #24 '-16Db'
; Item #25 '-17Db'
; Item #26 '-18Db'
; Item #27 '-19Db'
; Item #28 '-20Db'
; Item #29 '-21Db'
; Item #30 '-22Db'
; Item #31 '-40Db'
: values=30
root@aiv8365m1v1-aiot-emmc:~#

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
To set up the Mic-in audio recording, use the following command:
root@aiv8365m1v1-aiot-emmc:~# setup_mic
root@aiv8365m1v1-aiot-emmc:~# arecord -D hw:0,3 -f S16_LE -r 16000 /data/sda1/t1.wav
3.8 Camera
To preview an image from the CSI camera, use the following command:
root@aiv8365m1v1-aiot-emmc:~# gst-launch-1.0 v4l2src device="/dev/video5" ! video/x-raw,form
at=YUY2,width=1920,height=1080,framerate=30/1 ! videoconvert ! glimagesink sync=false
To capture an image from the CSI camera, use the following command:
root@aiv8365m1v1-aiot-emmc:~# gst-launch-1.0 v4l2src device="/dev/video5" io-mode=dmabuf
num-buers=1 ! video/x-raw,format=YUY2,width=1920,height=1080 ! jpegenc ! lesink location=/
data/sda1/t1.jpg
To record a video le from the CSI camera, use the following command:
root@aiv8365m1v1-aiot-emmc:~# gst-launch-1.0 v4l2src device="/dev/video5" num-
buers=300 io-mode=dmabuf ! video/x-raw,format=YUY2,width=1920,height=1080,framera
te=30/1 ! v4l2video2convert output-io-mode=dmabuf-import capture-io-mode=dmabuf ! video/x-
raw,format=NV12 ! v4l2h264enc output-io-mode=dmabuf-import ! avimux ! lesink location=/
data/sda1/t1.avi
To playback a record video le from the CSI camera, use the following command:
root@aiv8365m1v1-aiot-emmc:~# gst-launch-1.0 -q playbin uri=le:/data/sda1/t1.avi ags=0x42
video-sink="mtkmdp width=640 height=480 ! video/x-raw,format=I420 ! mtkwaylandsink" audio-
sink="autoaudiosink"
3.9 Wi-Fi
To verify the Wi-Fi funcon, use the following command:
root@aiv8365m1v1-aiot-emmc:~# wpa_cli -i wlan0 -p /tmp/wpa_supplicant add_network
root@aiv8365m1v1-aiot-emmc:~# wpa_cli -i wlan0 -p /tmp/wpa_supplicant set_network 0 ssid
'"via_test"'
root@aiv8365m1v1-aiot-emmc:~# wpa_cli -i wlan0 -p /tmp/wpa_supplicant set_network 0 psk
'"12345678"'
root@aiv8365m1v1-aiot-emmc:~# wpa_cli -i wlan0 -p /tmp/wpa_supplicant set_network 0 key_mgmt
WPA-PSK
root@aiv8365m1v1-aiot-emmc:~# wpa_cli -i wlan0 -p /tmp/wpa_supplicant select_network 0
Note:
Must change the Wi-Fi AP "'ssid"' and "'psk"' to the desired values. The '"via_test"' and '"12345678"' are in this
example.
To verify if the Wi-Fi connecon is workable, enable the interface, with the following command:
root@aiv8365m1v1-aiot-emmc:~# udhcpc -b -i wlan0
udhcpc: started, v1.31.1
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending select for 192.168.0.100
udhcpc: lease of 192.168.0.100 obtained, lease time 3600
/etc/udhcpc.d/50default: Adding DNS 8.8.8.8

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VIA SOM-9X35-STK Yocto 3.1 EVK Quick Start Guide
Then use the "ping" command to verify the network connecon:
root@aiv8365m1v1-aiot-emmc:~# ping 8.8.8.8
3.10 Bluetooth
To enter "interacve mode" for Bluetooth funcon vericaon, use the following commands:
root@aiv8365m1v1-aiot-emmc:~# btmw-rpc-test
increase the priority of btmw_rpc_test.i4_ret:0 @ main
set btmw_rpc_test priority done
[Client]Func:main Line:665--->: IPC/RPC initialize
YZ rpc_init is called
...
...
<I> [BTMW_RPC_TEST] init ok Normal Mode
<I> [BTMW_RPC_TEST] running.
btmw_test_cli>
In the example below, use a Bluetooth speaker to test.
First, get the Bluetooth speaker MAC address, which is "41:42:FC:81:75:7F" in this example.
To verify the Bluetooth funcon, use the following commands (using the speaker's MAC address in line 4 and
line 5):
btmw_test_cli> MW_RPC_GAP power 1
...
btmw_test_cli> MW_RPC_GAP set_conn_disc 1 1
...
btmw_test_cli> MW_RPC_GAP name mtk350
...
btmw_test_cli> MW_RPC_GAP pair 41:42:FC:81:75:7F 1
...
btmw_test_cli> MW_RPC_A2DP_SRC connect 41:42:FC:81:75:7F
...
btmw_test_cli> MW_RPC_A2DP_SRC write_stream /data/sda1/test.wav
...
btmw_test_cli>

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