Kontron AM4211 - Manual (Page 52)

37 AM4211
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5.1.4 E-Keying
E-Keying has been defined in the AMC.0 Specification to prevent board damage, prevent wrong operation,
and verify fabric compatibility. The FRU data contains the AMC Point-to-Point Connectivity record as
described in Section 3.9 of the AMC.0 R2.0 specification.
When the Module is inserted in an ATCA AMC carrier or MicroTCA system, the carrier manager reads in the AMC
Point-to-Point Connectivity record from FRU and determines whether the Board can enable the ports to the
AMC connector. Set/Get AMC Port State IPMI commands defined by the AMC.0 specification are used for
either granting or rejecting the E-keys.
5.1.5 Watchdog
The complete startup and execution process is guarded using external watchdog timers implemented by the
hardware management subsystem IPMC. There are 4 distinct watchdog timers running during:
•boot initialization and early boot monitor execution
•boot monitor execution and preparation for OS loading
•OS execution and initialization
The watchdog timers will trigger a specific action when expired. The action is dependent on previous resets
and on watchdog type.
The standard IPMI watchdog as implemented by the Linux IPMI driver supports different actions on watchdog
timer expiry and a configurable watchdog pre-timeout.
This pre-timeout period is configurable from 1 second up. The pre-timeout allows application software to
take actions just before the watchdog is triggered and causes a reset or error-halt-state. The pre-timeout
action can either be configured to trigger a Linux kernel panic, where appropriate panic-handlers can collect
data, or to inform a user-space application of the pre-timeout event.
5.1.6 MMC Firmware Code
MMC firmware code is organized into boot code and operational code, both of which are stored in a flash
module. Upon an MMC reset, the MMC executes the boot code and performs the following:
•Self test to verify the status of its hardware and memory.
•Calculates a checksum of the operational code.
Upon successful verification of the operational code checksum, the firmware will jump to the operational
code.