View source for UCM-iMX93: Yocto Linux: How-To Guide

=Device Tree=
== Available Device Tree Files ==
The current release includes the following '''dtb''' files:
{| class="wikitable" style="text-align:left;"
|-
| align="center" | '''DTB''' 
| align="center" | '''Hardware Configuration and Features'''
| align="center" | '''Jumpers/Connectors Settings'''
|-
| align="" |ucm-imx93.dtb
| align="" |default hardware configuration + mipi dsi display
| align="" |P11/P12 mipi iface/touch is in use
|-
| align="" |ucm-imx93-lvds.dtb
| align="" |default hardware configuration + lvds display 
| align="" |P7/P8 lvds iface/touch is in use
|-
| align="" |ucm-imx93-headless.dtb
| align="" |default hardware configuration w/out any display
| align="" |
|-
|}

==Set device tree==
The current release provides two methods to switch between dtb files:
* U-Boot environment
The U-boot '''fdtfile''' variable contains the device tree name that will be loaded into the RAM.
This variable can be changed by:
{| class="wikitable" style="text-align:left;"
|-
| align="" | '''Environment''' 
| align="" | '''Command''' 
|-
| align="" |U-Boot
| align="" |setenv fdtfile <fdt_file_name>; saveenv;
|-
| align="" |Linux
| align="" |fw_setenv fdtfile <fdt_file_name>
|-
|}
* GRUB environment (if the image was created with the meta-compulab-uefi layer)
{| class="wikitable" style="text-align:left;"
|-
| align="" | '''Environment''' 
| align="" | '''Command/Procedure''' 
|-
| align="" |GRUB Boot Menu
| align="" |Goto "Advanced Boot Options" and choose a device tree from the provided dtb list.
|-
| align="" |Linux
| align="" |grub-editenv /boot/grub/grubenv set fdtfile=<fdt_file_name>
|-
|}

= Serial Console =
UCM-iMX93 provides serial console on UART1.</br>
SB-UCMIMX93 evaluation carrier-board exposes the console UART via CP2104 serial-to-USB bridge on connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''P16''']].
== Connecting to a host PC ==
# Use a micro-USB cable to connect the console connector '''P16''' to a USB port on your host PC.
# Make sure the CP2104 driver is available with your operating system, otherwise install CP2104 driver onto the host PC from https://www.silabs.com/documents/public/software/CP210x_Windows_Drivers_with_Serial_Enumeration.zip
# Identify the host PC interface and port number that will be used for communication with the UCM-iMX93 evaluation kit:
#* In most Linux PCs, the serial port will be denoted as one of the following (where n is a positive integer): /dev/ttyUSB0, /dev/ttyUSB1 ... /dev/ttyUSBn
#* In Windows PCs, the serial port usually will be denoted as one of the following (where n is a positive integer): COM1, COM2 ... COMn
# Start a terminal emulation program (such as [https://www.putty.org/ PuTTY] on Windows or minicom on Linux).
# In the port configuration section of the terminal emulation program select the port identified in previous step and set the following serial port parameters:
<blockquote>
{{:SB-SOM: serial port parameters table}}
</blockquote>

=Display=
==MIPI-DSI==
The UCM-iMX93 evaluation kit includes the Startec KD050HDFIA 5" MIPI-DSI LCD panel. 

Connect the MIPI-DSI display to connectors [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''P11''' and '''P12''']] on the SB-UCMIMX93 carrier-board.

The MIPI-DSI display is described in the following device tree include file (included in the default '''ucm-imx93.dtb''' device tree): ''arch/arm64/boot/dts/compulab/ucm-imx93-mipi.dtsi''
<!--
descriptors of hw device for the drivers
* soc side - soc@0/dsi@4ae10000
* display device - soc@0/dsi@4ae10000/panel@0
driver can be found by the compatibility string i.e.
 cat /proc/device-tree/soc@0/dsi@4ae10000/compatible
 cat /proc/device-tree/soc@0/dsi@4ae10000/panel@0/compatible
-->
The Linux device node for the MIPI-DSI display:
 /sys/class/drm/card0/card0-DSI-1/
This device node contains information about the display, such as its supported modes and its current configuration.

==LVDS==
SB-UCMIMX93 supports direct connection with the Startec KD070HDTLA020 7" LVDS LCD panel.
Connect the display data cable to connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''P7''']].
Connect the display touch-panel cable to connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''P8''']].

LVDS display requires the following device tree: '''ucm-imx93-lvds.dts'''.

The Linux device node for the display is described in: ''arch/arm64/boot/dts/compulab/ucm-imx93-lvds.dtsi''.

==Display Manager==
UCM-iMX93 Yocto uses Weston as the default display manager. It can be configured in ''/etc/xdg/weston/weston.ini''.</br>
For example the transform setting can be set to rotate-90, rotate-180, rotate-270, or commented out.</br>
In order to apply the configuration, you need to restart the weston display manager:
 systemctl stop weston
 systemctl start weston

=Camera=
The UCM-iMX93 evaluation kit supports the e-con e-CAM131_CUMI1335_MOD 13MP 4K camera module.</br>
Connect the camera to connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''P9''']] on the SB-UCMIMX93 carrier-board.

The following device tree file should be used for camera operation: '''ucm-imx93-mipi-csi.dtb'''

Verify that the '''mxc-isi-cap''' driver is registered correctly:
<pre>
root@ucm-imx93:~# v4l2-ctl --list-devices
mxc-isi-cap (platform:4ae40000.isi:cap_devic):
        /dev/video0

FSL Capture Media Device (platform:mxc-md):
        /dev/media0
</pre>

The camera device tree nodes are described in: ''arch/arm64/boot/dts/compulab/ucm-imx93.dtsi''.</br>
<!--
* camera interface: /soc@0/bus@42000000/i2c@42530000/mipi2@42
* soc camera controller /soc@0/bus@42800000/camera/csi@4ae00000

kernel drivers:
* camera side: ar1335_af
* soc side V4L2 Media Controller: imx8_media_dev
-->
The Linux video device node used for capturing: '''/dev/video0'''

==Video Capturing==
Single image capturing:
 gst-launch-1.0 v4l2src num-buffers=1 ! jpegenc ! filesink location=single_buffer.jpg

Output to wayland surface:
 gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,width=1280,height=720,format=BGRA' ! textoverlay text="CLAB UCM-iMX93" ! waylandsink window-width=1280 window-height=720

To find a pipe element run:
 gst-inspect-1.0 | grep sink -i

Detailed information on a specific pipe element:
 gst-inspect-1.0 <name>

To learn more please refer to:

https://linuxtv.org/wiki/index.php/V4L_capturing

https://en.wikipedia.org/wiki/GStreamer

= USB =
UCM-IMX93 features two USB2.0 ports that are derived from the i.MX93 USB sub-system.<br>
On SB-UCMIMX93 evaluation carrier-board USB ports are available on the following connectors:

{| class="wikitable" style="text-align:left;"
|-
| align="center" | '''USB port#''' 
| align="center" | '''HW setting''' 
| align="center" | '''Connector''' 
| align="center" | '''Mode''' 
|-
| align="center" |1
| align="" |'''P21''' is not used
| align="" |type-A '''J5'''
| align="center" |host
|-
| align="center" |1
| align="" |'''P21''' connected to USB host
| align="" |micro-USB '''P21'''
| align="center" |device
|-
| align="center" |2
| align="" |jumper '''E11''' is open
| align="" |type-A '''J6'''
| align="center" |host
|-
| align="center" |2
| align="" |jumper '''E11''' is closed
| align="" |mini-PCIe '''P18'''
| align="center" |host
|}

== USB #1 in device mode ==
USB #1 port can be operated in device mode when connected to a host machine using connector '''P21'''.</br>
Available gadgets for the UBS #1 in device mode:
{| class="wikitable" style="text-align:left;"
|-
|align=""|'''USB gadget''' 
|align=""|'''SOM command'''
|-
|align=""|usb serial device
|align=""|modprobe g_serial
|-
|align=""|usb network device
|align=""|modprobe g_ether
|-
| align="" |usb mass storage device
| align="" |modprobe g_mass_storage file=/dev/sdX
|-
|}

=CAN bus=
UCM-iMX93 features two Flexible Controller Area Network (FLEXCAN) modules.
SB-UCMIMX93 evaluation carrier-board exposes one CAN bus interface on connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''J21''']].

==CAN interface configuration==
It is recommended configure the CAN interface, with the {{filename|iproute2}} utilities.

* To make sure the right '''ip''' utility is used, run:
<pre>
ip -V
ip utility, iproute2-v5.7.0-77-gb687d1067169 
</pre>
* Configure both CAN interface bit-rate to 1 Mbit/sec:
<pre>
ip link set can0 type can bitrate 1000000
</pre>
* Enable the CAN interface:
<pre>
ip link set can0 up
</pre>

==Send/Receive packets==
Use {{filename|cansend}} and {{filename|candump}} utilities to send and receive packets via CAN interface.

* Send standard CAN frame (on the first device):
<pre>
cansend can0 111#1122334455667788
</pre>

* Send extended CAN frame (on the first device):
<pre>
cansend can0 11111111#1122334455667788
</pre>

* CAN frames (extended mode) generator, random payload, interval between two successive flames 50 msec:
<pre>
cangen -g 50 -e -D r -v can0

can: raw protocol (rev 20170425)
...
  can0  03FF0983#D7.61.FF.03.C1.F7.C1.34
  can0  19C34D32#F7.5A.C2.73.AD.0E.3F.0B
  can0  0675E391#2B.2D.D3.49
  can0  13091C55#99.32.EC.77.27.81.49.0B
  can0  098D67CF#22.50.AB.48.AD.7F.F4.26
  can0  05263FEC#1B.4C.02.45.6E
  can0  12B30E20#
  can0  1F193DF9#C5
  can0  1EB0B18F#3E.3F.DA.57.C2.FE.73.58
  can0  1E5C64D9#6F.0D.B3.63.6A
  can0  1E1DE3F9#96.48.AC.79.4E.00.27.71
  can0  0E1A11B7#75.81.70.7C.86.79.A7.77
  can0  05F8FD8B#33.F9.9B.1E.77.3D.1F
  can0  1E155FCD#E6.BA.F8.58.ED.6D.C8.10
  can0  1D91DF9E#5D.29.82.7B.97.1D.AB.5C
  can0  11FB3CDA#14.65.C3
  can0  091352C0#2C.ED
...
</pre>

* Dump all received data frames as well as error frames (on the second device):
<pre>
candump any,0:0,#FFFFFFFF

  can0  111   [8]  11 22 33 44 55 66 77 88
  can0  11111111   [8]  11 22 33 44 55 66 77 88
...
  can0  03FF0983   [8]  D7 61 FF 03 C1 F7 C1 34
  can0  19C34D32   [8]  F7 5A C2 73 AD 0E 3F 0B
  can0  0675E391   [4]  2B 2D D3 49
  can0  13091C55   [8]  99 32 EC 77 27 81 49 0B
  can0  098D67CF   [8]  22 50 AB 48 AD 7F F4 26
  can0  05263FEC   [5]  1B 4C 02 45 6E
  can0  12B30E20   [0] 
  can0  1F193DF9   [1]  C5
  can0  1EB0B18F   [8]  3E 3F DA 57 C2 FE 73 58
  can0  1E5C64D9   [5]  6F 0D B3 63 6A
  can0  1E1DE3F9   [8]  96 48 AC 79 4E 00 27 71
  can0  0E1A11B7   [8]  75 81 70 7C 86 79 A7 77
  can0  05F8FD8B   [7]  33 F9 9B 1E 77 3D 1F
  can0  1E155FCD   [8]  E6 BA F8 58 ED 6D C8 10
  can0  1D91DF9E   [8]  5D 29 82 7B 97 1D AB 5C
  can0  11FB3CDA   [3]  14 65 C3
  can0  091352C0   [2]  2C ED
...
</pre>

= WiFi =
UCM-iMX93 features 802.11ac wireless connectivity solution implemented with an NXP 88W8997 module.<br>
The [https://manpages.debian.org/stretch/network-manager/nmcli.1.en.html NetworkManager] can be used to manage WiFi interface.
{{Note|Before working with WiFi, please ensure that WiFi antenna is connected to the SOM.}}

== Enable/Disable WiFi Interface ==
* To enable WiFi interface:
:<pre>nmcli radio wifi on</pre>
* To disable WiFi interface:
:<pre>nmcli radio wifi off</pre>

== Network Scanning ==
* Sample WiFi scanning:
:<pre>nmcli dev wifi list</pre>
:The output will show the list of Access Points and Ad-Hoc cells in range.

== Connecting to Access Point ==
In the following example:
* Replace <SSID> and <PASSWORD> with the actual access point parameters:
:<pre>nmcli device wifi connect <SSID> password <PASSWORD> name WifiCon</pre>
* Disconnect wireless network:
:<pre>nmcli connection down WifiCon</pre>
* Connect wireless network again:
:<pre>nmcli connection up WifiCon</pre>

== Creating Access Point ==
In the following example:
* Replace <SSID> and <PASSWORD> with desired access point parameters:
:<pre>nmcli device wifi hotspot ssid <SSID> password <PASSWORD> con-name HotspotCon</pre>
* Disable wireless AP:
:<pre>nmcli connection down HotspotCon</pre>
* Enable wireless AP again:
:<pre>nmcli connection up HotspotCon</pre>

= Bluetooth =
UCM-iMX93 features Bluetooth connectivity implemented with an NXP 88W8997 module.<br>

{{Note|Before working with Bluetooth, please ensure that Bluetooth antenna is connected to the SOM.}}


To start '''bluetoothctl''' use the following command:
<pre>
bluetoothctl
</pre>

To start the scan process use the following commands:
<pre>
[bluetooth]# default-agent
[bluetooth]# power on
[bluetooth]# scan on
</pre>

Bluetooth device should be turned on and visible. Its MAC-adress and name should appear in '''bluetoothctl''' in following format:
<pre>
[CHG] Device AA:BB:CC:DD:EE:FF Name: Device_Name
</pre>

To pair with the Bluetooth device use the following command:
<pre>
pair AA:BB:CC:DD:EE:FF
</pre>

Where '''AA:BB:CC:DD:EE:FF''' is MAC-adress of the Bluetooth device.

To quit '''bluetoothctl''' use the following command:
<pre>
[Device_Name]# quit
</pre>

=UART=
The following table outlines default UART routing when UCM-iMX93 is used with the SB-UCMIMX93 carrier-board:
{| class="wikitable" style="text-align:left;"
|-
| align="center" | '''UCM-iMX93 port''' 
| align="center" | '''Linux device''' 
| align="center" | '''on SB-UCMIMX93 carrier-board''' 
|-
| align="center" |UART1
| align="center" |/dev/ttyLP0
| align="" |converted to serial-over-USB debug console, micro-USB connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | P16]]
|-
| align="center" |UART2
| align="center" |/dev/ttyLP1
| align="" |converted to RS232, DB9 connector [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | P17]]
|-
| align="center" |UART5
| align="center" |/dev/ttyLP4
| align="" |routed to 100-mil header [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | P3]]
|-
| align="center" |UART7
| align="center" |/dev/ttyLP6
| align="" |converted to RS485, terminal block [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | J22]]
|-
|}

'''Example: testing UART5'''
* Short pin P3-1 (UART5-RX) with P3-3 (UART5-TX) on SB-UCMIMX93 to create a loop-back.
* Run the following commands:
 # stty -F /dev/ttyLP4 115200
 # cat /dev/ttyLP4 &
 # echo hello > /dev/ttyLP4
The "hello" string should appear on the terminal. 
<!--
For removing UART devices:
* Open ''arch/arm64/boot/dts/compulab/ucm-imx93.dtsi''
* Set desired UART device's status to 'disabled' 
* Recompile 
* Deploy the new dtb file
-->

=I2C=
The following I2C buses and devices are present when UCM-iMX93 is used with the SB-UCMIMX93 carrier-board:
{| class="wikitable" style="text-align:left;"
|-
| align="center" | '''Device''' 
| align="center" | '''I2C bus in Linux''' 
| align="center" | '''Address''' 
| align="center" | '''HW port in UCM-iMX93''' 
|-
| align="" |UCM-iMX93 EEPROM
| align="center" |0
| align="center" |0x50
| align="center" |I2C1 (internal)
|-
| align="" |UCM-iMX93 RTC
| align="center" |0
| align="center" |0x69
| align="center" |I2C1 (internal)
|-
| align="" |UCM-iMX93 PMIC
| align="center" |1
| align="center" |0x25
| align="center" |I2C2 (internal)
|-
| align="" |GPIO extender on SB-UCMIMX93 for on-board control signals 
| align="center" |2
| align="center" |0x20
| align="center" |I2C3
|-
| align="" |Camera module control on SB-UCMIMX93 connector P9
| align="center" |2
| align="center" |0x42
| align="center" |I2C3
|-
| align="" |SB-UCMIMX93 EEPROM
| align="center" |2
| align="center" |0x54
| align="center" |I2C3
|-
| align="" |Touch-screen controller of MIPI-DSI or LVDS panel on SB-UCMIMX93 connector P8 or P12
| align="center" |2
| align="center" |0x5d
| align="center" |I2C3
|-
|}
<!--
To list all available buses:
 # ls /dev/i2c-*
 /dev/i2c-0  /dev/i2c-1  /dev/i2c-2
-->
To list all mapped devices:
<pre>
# ls /proc/device-tree/soc@0/bus@*/i2c@*/*@* -d -w 1                                                                                                         
/proc/device-tree/soc@0/bus@42000000/i2c@42530000/goodix@5d
/proc/device-tree/soc@0/bus@42000000/i2c@42530000/mipi2@42
/proc/device-tree/soc@0/bus@42000000/i2c@42530000/pca9555@20
/proc/device-tree/soc@0/bus@44000000/i2c@44340000/rtc@69
/proc/device-tree/soc@0/bus@44000000/i2c@44350000/pmic@25
</pre>
Note how:
* each node is appended with its address.
* I2C buses order corresponds to the order of their addresses.

e.g. to inspect bus 0, in which we have RTC, run:
 # i2cdetect -y 0
      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
 00:                         -- -- -- -- -- -- -- -- 
 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
 50: 50 51 52 53 -- -- -- -- -- -- -- -- -- -- -- -- 
 60: -- -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- 
 70: -- -- -- -- -- -- -- --                         
In the above output numbers mark unused devices, UU marks a device that is used by a driver.

Indeed we see RTC in use at offset 0x69.

An example how to dump EEPROM contents:
 hexdump -C /sys/devices/platform/soc@0/44000000.bus/44340000.i2c/i2c-0/0-0050/eeprom

=SPI=

The following command displays listing of all of SPI devices in the system:
<pre>
root@ucm-imx93:~# find /proc/device-tree/ -name *spi*|grep soc
/proc/device-tree/soc@0/bus@44000000/spi@44370000
/proc/device-tree/soc@0/bus@44000000/spi@44360000
/proc/device-tree/soc@0/bus@42000000/spi@42560000
/proc/device-tree/soc@0/bus@42000000/spi@42700000
/proc/device-tree/soc@0/bus@42000000/spi@425e0000
/proc/device-tree/soc@0/bus@42000000/spi@426f0000
/proc/device-tree/soc@0/bus@42000000/spi@42710000
/proc/device-tree/soc@0/bus@42000000/spi@42720000
/proc/device-tree/soc@0/bus@42000000/spi@42550000
</pre>

=GPIO=
The following table outlines default GPIO assignments when UCM-iMX93 is used with the SB-UCMIMX93 carrier-board:
{| class="wikitable" style="text-align:left;"
|-
| align="center" | '''Signal Name 
| align="center" | '''On SB-UCMIMX93''' 
| align="center" | '''GPIO # in Linux''' 
|-
| align="center" |GPIO_IO04
| align="center" |P3-20
| align="center" |32+4
|-
| align="center" |GPIO_IO05
| align="center" |P3-18
| align="center" |32+18
|-
| align="center" |GPIO_IO07
| align="center" |P3-6
| align="center" |32+7
|-
| align="center" |GPIO_IO14
| align="center" |P5-4
| align="center" |32+14
|-
| align="center" |GPIO_IO15
| align="center" |P5-2
| align="center" |32+15
|-
| align="center" |GPIO_IO16
| align="center" |P3-4
| align="center" |32+16
|-
|}
These GPIOs belong to ''gpiochip0'' which numbering space starts at 32. Therefore it is required to add 32 to the GPIO number.
Other signals that are reserved for peripheral controls can be reassigned to function as GPIOs in ''arch/arm64/boot/dts/compulab/ucm-imx93-pinctrl.dtsi''.

==Example: controlling pin GPIO_IO16==
'''Exporting the pin in sysfs'''</br>
Create a file system export entry:
<pre>
cd /sys/class/gpio/
echo $((32+16)) > export
</pre>
Now pin GPIO_IO16 is assigned to sysfs. You can view the newly created entry in line 16 by running:
<pre>gpioinfo 0</pre>

'''Writing to a pin'''</br>
Go to GPIO_IO16 sysfs folder:
<pre>cd /sys/class/gpio/gpio$((32+16))</pre>
Set pin direction to output:
<pre>echo out > direction</pre>
Set pin value to high or low: 
<pre>
echo 1 > value 
echo 0 > value
</pre>
'''Reading from a pin'''</br>
Go to GPIO_IO16 sysfs folder:
<pre>cd /sys/class/gpio/gpio$((32+16))</pre>
Set pin direction to input:
<pre>echo in > direction</pre>
Read the value of the pin from the value file:
<pre>cat value</pre>

=Suspend / Resume=
{{note|The operation below requires '''root''' access.}}

UCM-iMX93 features suspend mode, which allows to minimize power consumption. 

The following command should be used to enter suspend mode:
<pre>
echo mem >/sys/power/state
</pre>

To resume normal operation press shortly the '''ON/OFF''' button [[UCM-iMX93: Evaluation Kit: Hardware Guide#Connector_Locations | '''SW5''']].

=CPU temperature=
i.MX93 SoC features an internal temperature sensor which allows to measure the SoC temperature.
Execute the following command to read the current CPU temperature:
<pre>
cat /sys/class/thermal/thermal_zone0/temp
</pre>

= RTC =
UCM-iMX93 features two RTC devices:
* i.MX93 internal RTC ('''rtc0''') - can be used as wake-up source
* AB1805 external RTC ('''rtc1''') - can be used for low current battery powered time keeping

== Internal RTC - rtc0 ==
System information:
<pre>
udevadm info -p /sys/class/rtc/rtc0

P: /devices/platform/soc@0/44000000.bus/44440000.bbnsm/44440000.bbnsm:rtc/rtc/rtc0
N: rtc0
L: -100
S: rtc
E: DEVPATH=/devices/platform/soc@0/44000000.bus/44440000.bbnsm/44440000.bbnsm:rtc/rtc/rtc0
E: DEVNAME=/dev/rtc0
E: MAJOR=251
E: MINOR=0
E: SUBSYSTEM=rtc
E: USEC_INITIALIZED=14959708
E: DEVLINKS=/dev/rtc
</pre>

Wake up:</br>
rtc0 can be used as a wake up source, as a result an '''rtcwakeup''' can be used with this device:
<pre>
rtcwake --device /dev/rtc0 -s 5 -m mem
</pre>

== External RTC - rtc1 ==
System information:</br>
<pre>
udevadm info -p /sys/class/rtc/rtc1

N: rtc1
L: 0
E: DEVPATH=/devices/platform/soc@0/44000000.bus/44340000.i2c/i2c-0/0-0069/rtc/rtc1
E: DEVNAME=/dev/rtc1
E: MAJOR=251
E: MINOR=1
E: SUBSYSTEM=rtc
</pre>

Set the date and write it into the RTC:</br>
<pre>
date -s "16 Jun 2023 12:00:00"

Fri 16 Jun 2023 12:00:00
hwclock --systohc --rtc /dev/rtc1
</pre>

Read the RTC time and date:</br>
<pre>
hwclock --show --rtc /dev/rtc1

2023-06-16 12:01:37.935876+00:00
</pre>

<!--=Device Serial Number=
The product serial number is a unique identifier that is assigned to each device during manufacturing. It can be used to troubleshoot problems.

To read the product serial number, run:
 root@ucm-imx93:~# cat /proc/device-tree/serial-number
-->

=See Also=
* [[UCM-iMX93: Evaluation Kit: Getting Started|Eval-kit Quick Start Guide]]
* [[UCM-iMX93: Evaluation Kit: Hardware Guide|Eval-Kit Hardware Guide]]

[[Category:Yocto]]
[[Category:UCM-iMX93]]