Specifications

QSSC-S4R Technical Product Specification Processor Presence and Population Check
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24. Processor Presence and Population Check
24.1.1 BSP Identification
The BMC cannot indicate which processor is the BSP. Software that needs to identify the BSP should use the
multiprocessor specification tables. See the BIOS EPS.
24.1.2 Boot Control Support
The BMC supports the IPMI 2.0 boot control feature that allows the boot device and boot parameters to be managed
remotely. The boot initiator mailbox is five 16-byte blocks.
24.1.3 Post Code Display
The BMC, upon receiving standby power, initializes internal hardware to monitor port 80h (POST code) writes. Data
written to port 80h is output to the system POST LEDs. Note that although the port 80h data is read by a hardware
FIFO, output to the LEDs is driven by firmware. This could lead to delays between the write and subsequent display on
the LEDs. There is also no flow control for port 80h writes, so a burst of data could result in the old POST codes being
dropped from the FIFO before being displayed on the LEDs.
The BMC core firmware does not guarantee any specific rate at which the FIFO’s contents will be displayed to the
LEDs.
The BMC deactivates POST LEDs after POST has completed.
24.2 Integrated Front Panel User Interface
This section describes the BMC’s role in supporting the system front panel buttons and LEDs.
The front panel has the following indicators:
x Power LED
x System status / fault LED
x Chassis ID LED
The front panel provides the following buttons:
x Reset button
x Power button
x System diagnostic interrupt button (NMI button)
x Chassis ID button
24.2.1 Power LED
The Power LED is controlled by the system BIOS. The BMC is unable to change the state of this LED. Please see the
system BIOS EPS for details on Power Status LED states.
24.2.2 System Status LED
Note: The system status LED shows the state for the current, most severe fault. For example, if there was a critical fault due to one
source and a non-critical fault due to another source, the system status LED state would be solid on (the state for the critical fault).
The system status / fault LED is a bi-color LED. Green (status) indicates normal (solid-on) or degraded (blink)
operation. Amber (fault) indicates a failure state, and overrides the green status. The system status LED is controlled
by the BMC, but includes non-BMC-owned sensors in fault determination (such as BIOS-owned sensors).
The BMC-detected states are included in the LED states. For fault states that are monitored by BMC sensors, the
contribution to the LED state follows the associated sensor state, with priority given to the most critical asserted state.
When the server is powered down (transitions to the DC-off state or S5), the BMC is still on standby power and retains
the sensor and front panel status LED state established before the power-down event. If the system status is normal
when the system is powered down (the LED is in a solid green state), the system status LED will be off.