This message will disappear after all relevant tasks have been resolved.
Semantic MediaWiki
There are 1 incomplete or pending task to finish installation of Semantic MediaWiki. An administrator or user with sufficient rights can complete it. This should be done before adding new data to avoid inconsistencies.The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
1 Purpose[edit source]
This article describes how to use the RTC.
2 How to set a hardware clock using the hwclock tool[edit source]
The correct system time must first be set with the date command. Type the date command to see the date and time format of the string:
date Fri Mar 9 12:18:51 UTC 2018
date --set="Fri Mar 9 19:18:51 UTC 2018" Fri Mar 9 19:18:51 UTC 2018
Set the hardware clock to this date:
hwclock Fri Mar 9 12:21:03 2018 0.000000 seconds hwclock --systohc --utc hwclock Fri Mar 9 19:19:52 2018 0.000000 seconds
See [1] for more about date settings. See [2] for more about hwclock settings.
3 How to set an alarm[edit source]
# disable the alarm
echo 0 > /sys/class/rtc/rtc0/wakealarm
# calculate alarm with 1 minute later
wakeuptime=`date -d "1 minute" +%s`
# set the alarm
echo $wakeuptime > /sys/class/rtc/rtc0/wakealarm
root@stm32mp1:~# [ 829.279019] rtc rtc0: Alarm occurred
You can also set an alarm 'n' seconds later:
echo +10 > /sys/class/rtc/rtc0/wakealarm
4 How to set an alarm and go into a system sleep state with the rtcwake tool[edit source]
# calculate an alarm 1 minute later
wakeuptime=`date -d "1 minute" +%s`
# set wakeup on /dev/rtc0 rtcwake -lt$wakeuptime -m mem rtcwake: wakeup from "mem" using /dev/rtc0 at Mon Mar 20 11:59:16 2023 [ 81.754154] PM: suspend entry (deep) [ 81.756533] Filesystems sync: 0.000 seconds [ 81.762182] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 81.769556] OOM killer disabled. [ 81.772612] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 81.780067] printk: Suspending console(s) (use no_console_suspend to debug)
One minute later...
NOTICE: CPU: STM32MP157CAA Rev.B NOTICE: Model: STMicroelectronics STM32MP157C eval daughter on eval mother NOTICE: Board: MB1263 Var1.0 Rev.C-01 INFO: PMIC version = 0x10 INFO: Reset reason (0x810): INFO: System exits from STANDBY INFO: FCONF: Reading TB_FW firmware configuration file from: 0x2ffe2000 INFO: FCONF: Reading firmware configuration information for: stm32mp_io NOTICE: BL2: v2.8-stm32mp1-r1.0(debug):openstlinux-23-03-17_next-2-g48077eaee0(48077eae) NOTICE: BL2: Built : 16:10:57, Mar 31 2023 INFO: BL2: Doing platform setup INFO: RAM: DDR3-DDR3L 32bits 533000kHz INFO: BL2: Skip loading image id 1 INFO: BL2: Skip loading image id 4 INFO: BL2: Skip loading image id 8 INFO: BL2: Skip loading image id 9 INFO: BL2: Skip loading image id 2 INFO: BL2: Skip loading image id 16 INFO: BL2: Skip loading image id 5 NOTICE: BL2: Booting BL32 INFO: Entry point address = 0x54000188 INFO: SPSR = 0x1d3 I/TC: Resumed I/TC: SeconI/TC: Secondary CPU 1 switching to normal world boot [ 81.789369] dwc2 49000000.usb-otg: suspending usb gadget configfs-gadget [ 81.922609] Disabling non-boot CPUs ... [ 81.923589] CPU1 killed. [ 81.924670] Enabling non-boot CPUs ... [ 81.930633] CPU1 is up [ 81.946846] dwmac4: Master AXI performs any burst length [ 81.946887] stm32-dwmac 5800a000.ethernet eth0: No Safety Features support found [ 81.946922] stm32-dwmac 5800a000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported [ 81.946990] stm32-dwmac 5800a000.ethernet eth0: configuring for phy/rgmii-id link mode [ 81.981951] usb usb2: root hub lost power or was reset [ 82.106798] dwc2 49000000.usb-otg: resuming usb gadget configfs-gadget [ 82.337015] onboard-usb-hub 2-1: reset high-speed USB device number 2 using ehci-platform [ 82.726126] OOM killer enabled. [ 82.729301] Restarting tasks ... done. [ 82.742746] random: crng reseeded on system resumption [ 82.754424] PM: suspend exit
See [3] for more about rtcwake settings.
5 How to get RTC status[edit source]
cat /proc/driver/rtc rtc_time : 07:25:13 rtc_date : 2000-01-01 alrm_time : 00:00:00 alrm_date : 2165-01-01 alarm_IRQ : no alrm_pending : no update IRQ enabled : no periodic IRQ enabled : no periodic IRQ frequency : 1 max user IRQ frequency : 64 24hr : yes
6 References[edit source]