Hot swap, 1 general, Am4120 ipmi firmware functional description – Kontron AM4120 IPMI Firmware User Manual

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AM4120 IPMI Firmware

Functional Description

ID 1045-9586, Rev. 1.0

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Clock Source:

When the AM4120 acts as clock source for the PCI Express reference clock, the clock signal
must be routed also to the PCI Express Endpoint. The backplane, the carrier’s IPMC or the
MCH must be capable of doing this (Clock E-Keying according to AMC.1 R2.0).

The information whether the AMC clock or the local clock is used as PCI Express reference
clock can be directly read from the board’s E-Keying clock configuration register (ICKEY0) at
address 0x297.

The DIP Switch SW3 can be used to forcibly configure the PCI Express reference clock. Please
refer to the AM4120 User Guide for details.

8.

U-Boot Failover Control - Automatic Flash
Selection

For normal operation, the MMC specifies the standard SPI NOR flash to be used for booting
and starts the payload. Then it waits for a message from the U-Boot bootloader. This message
contains a checksum report, i.e. it reports whether the boot flash's checksum is valid.

If either the checksum is invalid or the message is not received within a given time, the currently
used SPI NOR flash is assumed to contain a corrupted image. In this case, the MMC generates
a "Boot Error - Invalid boot sector" event for the related sensor. The sensor "FWH0 Boot Err"
indicates the boot error and generates the event for the standard SPI NOR flash. When booting
from the standard SPI NOR flash fails, the MMC selects the recovery SPI NOR flash, then the
board processor is reset and the MMC waits for the checksum report message from U-Boot
again.

In the event the recovery SPI NOR flash boot is successful, payload control is turned over to
U-Boot.

If again the checksum is invalid or the message is not received within a given time, the MMC
indicates the boot error with sensor "FWH1 Boot Err" and generates the event. The MMC re-
mains operable, however, now some form of intervention (human) on the part of the IPMI man-
agement system is required to resolve the failure of the module to properly boot.

9.

Hot Swap

9.1

General

As a hot-swappable field replaceable unit (FRU), the AM4120 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 AM4120
supports full hot swap capability as per PICMG 3.0. It can be removed from or installed in a
running system without powering-down the system. Please refer to the PICMG 3.0 specifica-
tion 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.

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