Kontron AM4022 IPMI Firmware - Manual (Page 41)

AM4022 IPMI Firmware
ID 1052-3624, Rev. 1.0 Page 41
9. OS Boot Order Selection by OEM IPMI
Normally the uEFI BIOS will apply the OS boot order which was selected in the uEFI BIOS
menu “uEFI Boot/Boot Option Priorities”. But there is another alternative boot order which is
stored in the IPMI controller's non-volatile memory. This boot order can be set and read by IPMI
OEM commands. At payload start the IPMI controller writes this boot order into a register where
the uEFI BIOS can read it. If this IPMI controller's boot order has a non-zero value, the uEFI
BIOS will use it instead of its own boot order.
10. Hot Swap
As a hot-swappable field replaceable unit (FRU), the AM4022 also follows the same stringent
carrier grade RASM feature set, namely - Reliability, Availability, Serviceability, Maintainability.
When offered in combination with AdvancedTCA platforms, TEM (Telecom Equipment Manu-
facturers) clients literally conserve valuable system AdvancedTCA system slots. The AM4022
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 spec-
ification 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 AM4022 supports ACPI, an OS on the payload side which supports this too makes shut-
down very easy. If the OS doesn't support ACPI, there is a special method to be used.
10.1 Method 1: The Payload OS Supports ACPI
Requirements:
• The ACPI daemon must be active.
• An ACPI power button event must result in a sleep state.
Hot swap operation sequence processed by MMC and OS:
• On command of the carrier controller, the MMC simulates the pressing and release of the
power button to force an ACPI event.
• The ACPI daemon detects this ACPI event and initiates the shutdown of the payload soft-
ware system.
• At the end of shutdown, the payload hardware system reports the sleep state to the MMC
by setting the appropriate signal line.
• The MMC detects the sleep state and reports this to the carrier controller (“quiesced”) so
that the hot swap processing can be continued and finished.
By default the MMC waits endlessly for the sleep state. Please note that some shelf managers
or MCHs use a timeout to simply switch off a module which needs too much time to reach sleep
state. As this might be an undesirable situation, refer to the appropriate manual for further as-
sistance. In any event, if an endless wait is to be avoided, it is possible to set a timeout time for
the module's MMC after which the system will be switched off unconditionally. For the setting
of the timeout refer to Chapter 3.4, OEM Module Quiescence Feedback.