Kontron IPMI Firmware - Manual (Page 15)

D R A F T — F O R I N
T E R N A L U S E O N L Y
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User Guide
IPMI Fimware
Case 2: Involves an OS which emulates ACPI support
An OS which does not really support ACPI, such as VxWorks, is able to obtain “Graceful Shutdown” sup-
port from the IPMI controller by performing in the following way.
After start-up, such an OS must manipulate the chipset in a way that prevents an immediate power-off
when the “power button” is logically activated.
Then it must send the IPMI command Set ACPI Power State / S0/G0 working to the
IPMI controller to enable this to process later on an S3/G2 soft off command.
During application operation the system must cyclically read the “Hot Swap Sensor” (sensor #0) using
the IPMI command Get Sensor Reading. This allows the tracking of the board's state. After the
board has once reached M-state 4 (sensor reading is 10h) the leaving of this announces that the handle
was opened. Now the time has come to terminate all processes.
After all critical processes have been terminated, the OS must send the IPMI command Set ACPI
Power State / S3/G2 soft off
to the IPMI controller which will set the power off immedi-
ately.
Case 3: Involves an OS which supports ACPI
When an OS is started which supports ACPI, the IPMI command Set ACPI Power State / S0/
G0 working
is sent to the IPMI controller. This indicates that the OS has reprogrammed the chipset
in such a manner that a “power button” signal does not lead to an immediate power-off but only causes
an event that can be detected by the OS.
When the handle is opened, the IPMI controller asserts the “power button” signal to notify the OS. The
OS then shuts down all processes and afterwards causes the transmission of the IPMI command Set
ACPI Power State / S3/G2 soft off
to the IPMI controller which then switches the power
off.
6.2 Hot Swap and Shutdown of an AMC Module
As a hot-swappable field replaceable unit (FRU), the board also follows the same stringent carrier
grade RASM feature set, namely — Reliability, Availability, Serviceability, Maintainability. When of-
fered in combination with AdvancedTCA platforms, TEM (Telecom Equipment Manufacturers) clients lit-
erally conserve valuable system AdvancedTCA system slots. The board supports full hot swap capability
as per PICMG 3.0. It can be removed from or installed in the system while it is on (without powering
down the system). Please refer to the PICMG 3.0 specification for additional details.
During hot swap of a working module, the payload side has to be shut down automatically on command
of the MMC and the end of shutdown has to be signalled back to the MMC. Because the board supports
ACPI, an OS on the payload side which supports this too makes shutdown very easy. If the OS doesn't
support ACPI, there is a special method to be used.