Kontron AM4140 IPMI Firmware - Manual (Page 36)

IPMI Firmware AM4140
Page 36 ID 1051-8188, Rev. 1.0
P R E L I M I N A R Y
8. U-Boot Failover Control - Automatic Flash
Selection
For normal operation, the MMC specifies the standard SPI boot 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 boot 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 boot flash. When booting
from the standard SPI boot flash fails, the MMC selects the recovery SPI boot flash, then the
board processor is reset and the MMC waits for the checksum report message from U-Boot
again.
In the event the boot from the recovery SPI boot flash 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 AM4140 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 AM4140
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 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.
9.2 OS Requirements for Graceful Shutdown
Requirements:
• At system start on the payload side, the Kontron shutdown daemon “grnsd” must be start-
ed. It is included in the Linux board support packages for the AM4140. This daemon com-
municates cyclically with the MMC for the exchange of states, commands and
acknowledges. For this, it uses the OEM Module Quiescence Feedback command.
Refer to Chapter 3.4.