Specifications

BIOS-BMC Interactions QSSC-S4R Technical Product Specification
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27. BIOS-BMC Interactions
BIOS-BMC interactions include the following:
x FRB2 Operation.
x POST Complete Signaling – BIOS asserts the POST Complete signal at the end of POST. BMC firmware monitors
this signal.
x Retrieval of Platform Information – BIOS may query firmware revisions for the BMC and attached satellite
controllers. BIOS may also read FRU device locator records from the BMC, to determine the system’s inventory.
Additionally, BIOS must use subsystem information to populate SMBIOS tables.
x System GUID Information – BIOS must send system GUID to the BMC on boot.
x SEL – The BIOS may add entries to the BMC’s system event log.
x Power Restore Policy – BIOS may operate on the BMC’s power restore policy to support BIOS setup functionality.
x ACPI – BIOS must notify the BMC of ACPI state changes.
x Front Panel Lockout – BIOS may operate on the BMC’s front-panel lockout to support BIOS setup functionality.
x Serial Port Sharing – BIOS must interact with the BMC to share the serial port for system use.
x Serial Console Redirection – BIOS redirects serial output to the BMC, for LAN-based serial redirection.
x BMC Self Test/Health – BIOS may query the BMC for self test results.
x Clock Synchronization – BIOS must synchronize the BMC’s clock with the system clock using the Set SEL Time
IPMI command.
x BIOS-monitored sensors – BIOS must notify the BMC of system faults such as DIMM failures using OEM IPMI
commands. The BMC uses this information to control the associated fault LEDs.
x BIOS must read the thermal profile data records from the BMC to determine appropriate thermal settings.
x BIOS may clear the SEL, per BIOS setup options.
x BIOS must bridge host information to the ME, through the BMC.
x BMC may interact with BIOS if a Set System Boot Options command requires altering the boot order.
x BIOS may query the BMC for board SKU and revision ID values.
x During Memory Hot Plug/Memory Online operation BIOS needs to send new DIMM population order to BMC, see
section 24.20 for details.