{{template>en:templates:tabs_sbc_yocto_bootstrap|product_type="Embedded SBC"|lang="intern"|mod_name="tqma8mpxl"|mod_name_head="MBa8MP-RAS314"|sbc_name="mba8mp-ras314"|mod_arch="arm"|bsp_name="linux"|build_system="Armbian"|build_system_head="Armbian"|bsp_name_head="Linux"}}

<panel type="default" title="Audio">
<grid>
<col sm="6">
<panel type="primary" title="Audio Connector Overview">
^ Connector ^ Function ^
| X3 | Headphone/Microphone |
</panel>
</col>
<col sm="6">
<panel type="primary" title="Audio Connector Location">
{{ :intern:arm:tqma8mpxl:mba8mp-ras314:linux:armbian:2023-10-24_09_27_30-raspi.docx_kompatibilitaetsmodus_-_word.jpg?nolink&400 |}}
</panel>
</col>
</grid>

**Play Audio on MBa8MP-RAS314**

A simple test sound can be played with the commandline tool speaker-test.\\
Headphones or active speakers have to be connected to X3 on MBa8MP-RAS314.

<code>
speaker-test --channels 2 --test wav
</code>

You can also play your own audio files using ''aplay'' 
<code>aplay <file></code>
e.g. 
<code>aplay test.wav</code>


<callout  type="primary" icon="true">
Please notice that no audio test files are available in the default image.
</callout>
<WRAP hide>
**Record Audio via Line-In on MBa8MP-RAS314**

<code>
arecord -f cd test.wav
</code>

<callout  type="info" icon="true">
The audio settings can be altered using ''amixer'' or ''alsamixer''
</callout>
</WRAP>
</panel>

<panel type="default" title="CPU">
The MBa8MP-RAS314 supports DVFS (dynamic voltage and frequency scaling, by default the governor ''schedutil'' is set.
Governors are power schemes for the CPU. Only one may be active at a time.
^ Governor ^ Description ^
| performance  | Run the CPU at the maximum frequency. |
| powersave    | Run the CPU at the minimum frequency. |
| userspace    | Run the CPU at user specified frequencies. |
| ondemand     | Scales the frequency dynamically according to current load. Jumps to the highest frequency and then possibly back off as the idle time increases. |
| conservative | Scales the frequency dynamically according to current load. Scales the frequency more gradually than ondemand. |
| schedutil    | Scheduler-driven CPU frequency selection |
You can change the actual governor with the following command:
<code>
cpufreq-set -g <governor>
(e.g. cpufreq-set -g performance)
</code>

==== Disable CPU Core temporarily ====

At runtime it is possible to disable multiple CPU cores via the Linux sysfs. On a system that has four CPU cores, the maximum of three cores can be disabled.
To disable the a CPU core value ''0'' must be written to the CPU core specific file ''/sys/devices/system/cpu/cpu<N>/online'' where <N> is the number of the Core, the counting starts at zero.     
\\ 
e.g. disable CPU core 4:
<code>
echo 0 > /sys/devices/system/cpu/cpu3/online
</code>

To check which CPU core(s) are currently enabled the following command can be used: 
<code>
grep "processor" /proc/cpuinfo
</code>  


The CPU core can be enabled again by writing the value ''1'' to ''/sys/devices/system/cpu/cpu<N>/online''.\\
\\
e.g. enable CPU core 4:
<code>
echo 1 > /sys/devices/system/cpu/cpu3/online
</code>

<WRAP hide>
==== Set ammount of CPU Cores permanently ====

It is possible to limit the maximium amount of cores with the  the ''maxcpus='' parameter in the kernel command line. To add the new parameter a new U-boot variable ''addcpu'' has to be created. 

<code>
setenv addcpu maxcpus=${cpu_num}
</code>

The amount of cores is set by the ''cpu_num'' variable, for example if cpu num is set to ''2'' only two cores will be started.

<code>
setenv cpu_num 2
</code>
</WRAP>
</panel>

<panel type="default" title="Ethernet">
The MBa8MP-RAS314 provides two Gigabit Ethernet interfaces.

<accordion collapsed="true">
<panel title="U-Boot">
In U-Boot eth0 is configured as default interface. The IP configuration can be done statically or by a DHCP server in the network.

** IP configuration via DHCP **

For a configuration via a DHCP server, use the ''dhcp'' command in U-Boot.

** Static IP configuration **
For a static IP configuration the following, U-Boot environment variables must be set:
<code>setenv ipaddr <ipaddr> 
(e.g.: setenv ipaddr 192.168.100.111)
setenv netmask <netmask> 
(e.g.: setenv netmask 255.255.255.0)
</code>
</panel>

<panel title="Linux">
Both Ethernet interfaces are activated and configured by systemd-networkd. The configuration files for the interfaces are located in /lib/systemd/network/ these configuration files can be altered to customize the default interface configuration. A documentation of the configuration files can be found [[https://www.freedesktop.org/software/systemd/man/systemd.network.html|here]].

| eth0  | 10-eth0.network  |
| eth1  | 10-eth1.network  ||

For a temporary static configuration the ip command can be used, below some useful ip commands are listed:\\ 
\\
**Activate a specific interface**\\
e.g. eth0
<code>
ip link set eth0 up
</code>
\\
**Disable a specific interace**\\
e.g. eth0
<code>
ip link set eth0 down
</code>
\\
**Show ip address for a specific interface**\\
e.g. eth0
<code>
ip addr show eth0
</code>
\\
**Show statistic for a specific interface**\\
e.g. eth0

<code> 
ip -s link show eth0 
</code>
\\
**Set ip address for a specific interface**\\
e.g. eth0

<code>
ip addr add 192.168.1.100/24 dev eth0
</code>
\\
**Show statistic of all interfaces**\\

<code>
ip -s link
</code>
\\
**Set default gateway for a specific interfaces**\\
e.g. set gateway ip 192.168.1.1 for eth0 
<code>
ip route add default via 192.168.1.1 dev eth0
</code>
----

If a DHCP server is available in the network environment the ip configuration can be received from it. To do so execute the ''udhcpc'' command, by default eth0 is used.\\
To configure another interface via dhcp the parameter ''-i''  followed by the interface name e.g. eth1 must be given.\\
e.g. eth1

<code>
dhclient 
</code>

</panel>
</accordion>
</panel>


<panel type="default" title="GPU">
Running a GPU benchmark requires a display (HDMI or LVDS) Please keep in mind to set the devicetree properly if LVDS is used.

The benchmark tools are not included in the standard image configuration. In order to use them, they have to be downloaded via APT package manager.

<callout type="info" icon="true">
Please note that the glmark2 test requires a Desktop environment, while the kmscube works on both image types.
</callout>

<code>sudo apt install kmscube</code>
or
<code>sudo apt install glmark2-es-drm</code>


The benchmark can be started by using the following terminal commands:
^ Image type ^ Command ^
| Minimal image  | <code> kmscube </code>|
| Desktop environment  | <code> glmark2-es2-drm </code> |

</panel>

<panel type="default" title="HDMI">
HDMI is enabled by default on all Armbian images for the MBa8MP-RAS314 board, no further configuration is required. 

</panel>

<panel type="default" title="LVDS">
TQ offers an optional LVDS Display kit for the MBa8MP-RAS314. To activate LVDS including the display configuration, the devicetree **imx8mp-tqma8mpql-mba8mp-ras314-lvds.dtb** has to be set in /boot/extlinux/extlinux.conf in the line beginning with "fdt"

<code>fdt /boot/dtb/freescale/imx8mp-tqma8mpql-mba8mp-ras314-lvds.dtb</code>

To load the LVDS devicetree restart the system.

</panel>

<panel type="default" title="RTC">
Set the hardware clock to the actual time and date use the following commands:
<code>date -s MMDDhhmmCCYY.ss
hwclock -w
</code>
</panel>

<panel type="default" title="SPI">

The MBa8MP-RAS314 has one SPI interface, it is routed to header X1 and can be tested with a loopback test.

<grid>
<col sm="6">
<panel type="primary" title="SPI Overview">
^ Interface ^ linux filesystem ^
| SPI3| /dev/spidev3.0  |
</panel>
</col>

<col sm="6">
<panel type="primary" title="Loopback Test SPI Interface">

The loopback test requires a bridge between SPI_MOSI and SPI_MISO:
  * SPI3: bridge between X1_20 (ECSPI3_MISO) and X1_19 (ECSPI3_MOSI)
<code>
echo -n -e "\x01\x0F" | spi-pipe -d <spi interface> -s 10000000 | hexdump
(e.g. echo -n -e "\x01\x0F" | spi-pipe -d /dev/spidev3.0 -s 10000000 | hexdump)
</code>
</panel>

</col>
</grid>

</panel>

<panel type="default" title="Temperature Sensors">
The MBa8MP-RAS314 has one temperature sensor, which is located on the TQMa8MPxL SOM.
^ Device ^ I²C Address  ^
| TQMa8MPxL  | 0x1B |
**Read TQMa8MPxL Temperature Sensor**
<code>
cat /sys/devices/platform/soc@0/30800000.bus/30a20000.i2c/i2c-0/0-000001b/hwmon/hwmon2/temp1_in
</code>

**Read CPU internal Temperature Sensor**\\
The i.MX8MPxL CPU has an internal TMU that supports two thermal zones, both can be read by the commands below:  

**Thermal zone0**
<code>
cat /sys/devices/virtual/thermal/thermal_zone0/temp
</code>

**Thermal zone1**
<code>
cat /sys/devices/virtual/thermal/thermal_zone1/temp
</code>

<callout type="info" icon="true">
The temperature is shown in millidegrees Celsius.
</callout>
</label>
</panel>

<panel type="default" title="USB">
With ''lsusb'' you can see all connected usb devices. To mount a partition of an usb stick you can excute ''mount /dev/<partition> <mount dir>'' (e.g. ''mount /dev/sdb1 /mnt)''. This will mount the first partition of sdb to /mnt. To unmount the device execute ''umount <mount dir>'' (e.g. ''umount /mnt'').
</panel>

<panel type="default" title="User LED">

The MBa8MP-RAS314 has two user LEDs, the behavior of these LEDs can be selected by several triggers.

<grid>
<col sm="6">
<panel type="primary" title="User LED Overview" no-body="true">
^ Reference  ^ LED name ^ color  ^ linux filesystem ^
| V2  | green:  | green  | /sys/class/leds/green:  |
| V3  | yellow:  | orange | /sys/class/leds/yellow:  |
</panel>
</col>

<col sm="6">
<panel type="primary" title="User LED Location" no-body="true">
{{ :intern:arm:tqma8mpxl:mba8mp-ras314:linux:armbian:2023-10-24_08_26_58-mba8mp-ras314.bp.scaled.1v2.pdf.jpg?nolink&400 |}}
</panel>
</col>
</grid>

The user LED's are located in /sys/devices/platform/gpio-leds/leds/.\\
To change the behaviour of a specific LED, the value in the file trigger must be overwritten.

++++The following values are valid:|

  * none 
  * bluetooth-power 
  * kbd-scrolllock 
  * kbd-numlock 
  * kbd-capslock 
  * kbd-kanalock 
  * kbd-shiftlock 
  * kbd-altgrlock   
  * kbd-altlock
  * kbd-shiftllock
  * kbd-shiftrlock
  * kbd-ctrllock
  * kbd-ctrlllock
  * kbd-ctrlrlock
  * mmc0
  * disk-activity
  * disk-read
  * disk-write
  * ide-disk
  * heartbeat
  * cpu
  * cpu0
  * cpu1
  * cpu2
  * cpu3
  * default-on
  * panic
  * mmc1

++++

For example set the trigger of "green:" to heartbeat 

<code>
echo heartbeat > green:</code>

</panel>

<panel type="default" title="SSH Connection">
<alert type="warning" icon="fa fa-warning">Please keep in mind that the following instructions focus on simplicity, not on security.</alert>

In order to access the starter kit via SSH, open a terminal under linux or a terminal programme, e.g. PuTTY, and connect to the starter kit with the IP that was assigned to the starter kit by the dhcp client, or in the terminal using <code>ssh root@mba8mpxl-ras314</code>
 When the system is started for the first time, the password "1234" must be used. Afterwards, in the Armbian setup, you can then set your own password.

<callout type="primary" icon="true">
If several MBa8MPxL-RAS314 boards with the same name are connected to the same network, connection problems may occur using SSH if they are not accessed via the IP address.
</callout>

The file /etc/ssh/sshd_config is used to configure the SSH service. To be able to login with a password as user root change the following lines in the Authentication section

<code>PermitRootLogin prohibit-password</code>
to <code>PermitRootLogin yes </code> and
<code>#PasswordAuthentication yes</code>
to
<code>PasswordAuthentication yes</code>

After altering the SSH configuration, the SSH service must be restarted to apply the new configuration:
<code>systemctl restart sshd.socket</code>

To setup a password for a user, 
execute the command ''passwd <username>'', e.g. ''passwd root'' for the default user root, and set your password. Afterwards execute the ''login'' command to login the user with the new password.  \\ 

</panel>