Watchdog Timer; System Event Log (Sel) - Intel SE7520BD2 Technical Product Specification

Intel® Server Board SE7520BD2 Technical Product SpecificationPlatform Management Architecture
4.2.7.1 Wake On LAN in S4/S5
A configuration option is provided that allows the onboard NICs to be enabled to wake the
system in an S4/S5 state, even if the operating system disabled Wake-On-LAN when it powered
down the system. This provides an option for users who want to use standard, but non-secure,
WOL capability for operations such as after-hours maintenance. Note that the DPC LAN
capability provides a secure system power-up, plus the ability to provide BIOS boot options, by
sending authenticated IPMI messages directly to the BMC via the onboard NICs.
4.2.8

Watchdog Timer

The mBMC implements an IPMI 1.5-compatible watchdog timer. See the IPMI specification for
details. SMI and NMI pre-timeout actions are supported, as are hard reset, power down, and
power cycle timeout actions.
4.2.9

System Event Log (SEL)

The mBMC implements the logical System Event Log device as specified in the Intelligent
Platform Management Interface Specification, Version 1.5. The SEL is accessible via all
communication transports. In this way, the SEL information can be accessed while the system is
down by means of out-of-band interfaces. The maximum SEL size that is supported by mBMC
is 92 entries.
Supported commands are:
•
Get SEL Info
•
Reserve SEL
•
Get SEL Entry
•
Add SEL Entry
•
Clear SEL
•
Get SEL Time
•
Set SEL Time
4.2.9.1 SEL Erasure
TBD
4.2.9.2 Timestamp Clock
The mBMC maintains a four-byte internal timestamp clock used by the SEL and SDR
subsystems. This clock is incremented once per second. It is read using the Get SEL Time
command and set using the Set SEL Time command. The Get SDR Time command can also be
used to read the timestamp clock. These commands are specified in the Intelligent Platform
Management Interface Specification, Version 1.5.
After a mBMC reset or power up, the mBMC sets the initial value of the timestamp clock to
0x00000000. It is incremented once per second after that. A SEL event containing a timestamp
from 0x00000000 to 0x140000000 has a timestamp value that is relative to mBMC initialization.
During POST, the BIOS tells the mBMC the current time via the Set SEL Time command. The
mBMC maintains this time, incrementing it once per second, until the mBMC is reset or the time
is changed via another Set SEL Time command.
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