Penguin Computing Relion 1900e, Technical Manual

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Relion 1900e/2900e Manual
29 Revision 1.3
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Memory Mapped I/O (MMIO)
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Manageability Engine (ME)
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BIOS flash
4.8 Memory Initialization
Memory Initialization at the beginning of POST includes multiple functions, including:
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DIMM discovery
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Channel training
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DIMM population validation check
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Memory controller initialization and other hardware settings
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Initialization of RAS configurations (as applicable)
There are several errors which can be detected in different phases of initialization. During early POST, before
system memory is available, serious errors that would prevent a system boot with data integrity will cause a
System Halt with a beep code and a memory error code to be displayed via the POST Code Diagnostic LEDs.
Less fatal errors will cause a POST Error Code to be generated as a Major Error. This POST Error Code will be
displayed in the BIOS Setup Error Manager screen, and will also be logged to the System Event Log (SEL).
4.8.1 DIMM Discovery
Memory initialization begins by determining which DIMM slots have DIMMs installed in them. By reading the
Serial Presence Detect (SPD) information from an SEEPROM on the DIMM, the type, size, latency, and other
descriptive parameters for the DIMM can be acquired.
Potential Error Cases:

Memory is locked by Intel® TXT and is inaccessible – This will result in a Fatal Error Halt 0xE9.
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DIMM SPD does not respond – The DIMM will not be detected, which could result in a “No usable
memory installed” Fatal Error Halt 0xE8 if there are no other detectable DIMMs in the system. The
undetected DIMM could result later in an invalid configuration if the “no SPD” DIMM is in Slot 1 or 2
ahead of other DIMMs on the same channel.
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DIMM SPD read error – This DIMM will be disabled. POST Error Codes 856x “SPD Error” and 854x
“DIMM Disabled” will be generated. If all DIMMs are failed, this will result in a Fatal Error Halt 0xE8.
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All DIMMs on the channel in higher-numbered sockets behind the disabled DIMM will also be
disabled with a POST Error Code 854x “DIMM Disabled” for each. This could also result in a “No
usable memory installed” Fatal Error Halt 0xE8.
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No usable memory installed – If no usable (not failed or disabled) DIMMs can be detected as installed
in the system, this will result in a Fatal Error Halt 0xE8. Other error conditions which cause DIMMs to
fail or be disabled so they are mapped out as unusable may result in causing this error when no
usable DIMM remains in the memory configuration.
4.8.2 DIMM Population Validation Check
Once the DIMM SPD parameters have been read they are checked to verify that the DIMMs on the given
channel are installed in a valid configuration. This includes checking for DIMM type, DRAM type and
organization, DRAM rank organization, DIMM speed and size, ECC capability, and in which memory slots the
DIMMs are installed. An invalid configuration may cause the system to halt.