yes, it is true
Is this issue reproducible on devkit?
I tested it with the Nano DevKit and the results were the same
Hi，
Is there a solution？
Does the board still have power supply provided after your so-called reboot/power off?
After the software is shut down, disconnect the power supply and then power it on again.
Hi,
Then I don’t think it is a bug… it is normal that system time would be gone… if no power supply and also no RTC.
Hi,
Yes, I know ,we just want to change the system’s default time and not use RTC to save the clock.
According to the default time shown by Date, I think you added the default time when you released the system.
I would like to know how to modify the system time so that it will be displayed after being powered on.
Hi,
Can RTC initial time 2000-01-01 be changed?
Still checking with internal team about this.
Hi,
Thank you very much. If you hear of something, let me know.
Hi,
The time logic here is
- It will check the timestamp of file /var/lib/systemd/timesync/clock
- If that’s earlier then the systemd compile time, it will use systemd compile time. Otherwise clock file timestamp will be used.
Thus, please put the timestamp you want to see in /var/lib/systemd/timesync/clock.
Hi，
Thank you very much， I tried, but it didn’t work
The steps are as follows：
sudo -s
touch -t 202208191640 /var/lib/systemd/timesync/clock
stat /var/lib/systemd/timesync/clock
The access time and change time are both 2022-08-19 16:40:00.000000000 +0800
poweroff. disconnect the power supply and then power it on again.
It still shows 2021.7.22
Is there a problem with my procedure？
Hi,
That is the normal behavior of systemd-timesyncd.
We’ve confirmed this is directly from ubuntu upstream rootfs. Thus, there is nothing we can help here.
You can write a service in each reboot to write a hardcoded value you want.
Hi，
I’m a little confused.
What “hardware value” do you mean?
Also, what are Ubuntu upstream rootfs?
你現在在用的Ubuntu是從upstream ubuntu18.04/20.04抓下來的. 裡面有很多tool/lib不是 nvidia建出來的.而是ubuntu那邊直接提供的.
你現在這個系統時間是由一個叫systemd-timesyncd的service 負責的. 之所以為何會一直跑到一個"hardcoded-value"（寫死的時間), 也是因為這個service提供的規定. 由於這個service不是我們提供的, 對於它的行為我們無法幫助.
NVIDIA didn’t build the whole" ubuntu" by ourself. There must be some tools that are directly from the Ubuntu 20.04/18.04 directly. That is what we call “Ubuntu upstream”.
There is a “systemd-timesyncd” which handles how the time would be decided. The reason why you always see that value is due the the rule from that service.
Hi，
I see.
For writing a service, do you have relevant links？
If so, please send it to me. Thank you very much for your support.
其實沒有特別的… 因為看來你只是要設定一個你想要的固定時間, 所以你可以就每次開機起來就用timedatectl去設定一次時間之類的…
那每次開機起來要怎樣跑script基本上就有很多方法… 你可以搜尋ubutnu常用的那幾種… rc.local/systemd之類的
Actually there is nothing special, it seems you just want to set a fixed time, so actually you can just run a script to use timedatectl to set time everytime.
As for how to run a script in each reboot, there are lots of ways in ubuntu and you can search it online… e.g. rc.local or systemd.
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Hi,
I see. Thank you very much.
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