Real-Time Clock
Revision as of 04:22, 15 April 2025 by JeremyRand (talk | contribs) (→Ownership: Link to Whonix's docs on Time Attacks)
Ownership
For security reasons, by default, the BMC owns the RTC; the host has read-only access to the RTC via IPMI. Whonix has documented a variety of security vulnerabilities that manifest if malware on the host is able to tamper with the RTC.
Setting the hardware real-time clock has no effect
If hwclock --systohtc
has no effect (i.e. hwclock --get
is unchanged), then:
1. From the BMC console, power off the host
2. Type busctl set-property xyz.openbmc_project.Settings /xyz/openbmc_project/time/owner xyz.openbmc_project.Time.Owner TimeOwner s xyz.openbmc_project.Time.Owner.Owners.Host
(note the capitalization: Host
, not HOST
as the openbmc github issues tell you!)
3. Reboot the BMC
4. Power on the host