Notes and information about EKF PC4-PRESTO UEFI/BIOS Firmware: ============================================================== 1) PC4-PRESTO does not start after power is reapplied ===================================================== Sometimes the system does not start after power is reapplied to the board. In almost all cases this is NOT caused by a hardware failure of the board! It is caused because the board enters S4 or S5 state after power-up (like a "normal" PC), instead of running state S0. Sleep states S4 or S5 are indicated by front panel LED PG=off and one or both LEDs GP/HD=ON). Chapter "PG (Power Good) LED" in User Guide of PC4-PRESTO describes this in detail: http://ekf.de/p/pc4/pc4_ug.pdf To bring the board back to working state the (red) ejector handle in front panel of PC4-PRESTO handle must simply be opened for a short time (less than 4 seconds). Technical background: On EKF PC4-PRESTO there are 4 reasons why the system enters S4/S5 (sleep) state after power-up, instead of S0 (running) state: 1. The corresponding bit in the SMBus unconditional power down message is set 2. PCH QM87 internal thermal sensor catastrophic condition (PCH QM87 overheating) 3. Assertion of THRMTRIP# signal at PCH QM87 (Processor overheating) 4. A Power Button Override event (pressing Power Button more than 4 seconds) 2) Invalid CMOS data ==================== If the UEFI/BIOS detects a bad checksum in CMOS data, CMOS is reset to default values during POST. The possible reasons for a bad CMOS checksum are: - An empty or weak battery - A board with NO battery In this case it makes sense to set Setup option "Ignore Battery Error" to Enabled - Any software writes to CMOS without updating the CMOS checksum bytes 3) Loading UEFI/BIOS Setup defaults =================================== For PC4-PRESTO these options exist to reset UEFI/BIOS Setup to default values: - key when in UEFI/BIOS Setup - Jumper J-GP set on system start (see PC4-PRESTO User Guide for more info) - UEFI/BIOS Firmware reprogramming 4) Secure Boot ============== Enable Secure Boot: 1. Start System 2. Press F2 to enter UEFI/BIOS Setup 3. Set a Supervisor Password Security -> Set Supervisor Password 4. Enable Secure Boot Feature Security -> Secure Boot Configuration -> Secure Boot -> Enabled 5. Press F12 to save configuration 6. Reboot system Secure Boot is now active. The system will not start any bootloader or EFI application, which is not signed by Microsoft Corporation or EKF Elektronik GmbH. 5) Support of CompactPCI peripheral boards with PCI-to-PCIe-Bridge ================================================================== Microsoft operating systems since Windows Vista and Windows 2008 support a feature named "PCI Express Native Control". If the operating system (Windows) invokes the "PCI Express Native Control" feature, PCI-to-PCIe-Bridges on peripheral boards will not start as expected (Error Code 10 in Windows Device Manager), cause this feature is not supported along with PCI-to-PCIe-Bridges (reverse bridges). The issue is relevant for EKF peripheral boards listed below: CB3, CE3, CK2, CL1, CL2, CN7, CP4, CP5 and CV2 There are two options to resolve this issue: 1. Disable "PCI Express Native Control" in UEFI/BIOS - Turn on the system - Press F2 to enter UEFI/BIOS Setup settings - Navigate to "Advanced -> ACPI Configuration" - Set "Native PCI Express Features" to Disabled 2. Disable "PCI Express Native Control" in Windows - Boot to Windows - Open a command prompt ("cmd") as administrator - Execute: "bcdedit /set {current} pciexpress forcedisable" to disable "PCI Express Native Control" [If you want to re-enable "PCI Express Native Control" execute: "bcdedit /set {current} pciexpress default"] - Reboot the system Notice that disabling of "PCI Express Native Control" may cause loss of other system features like: - PCI Express Native Hot Plug - PCI Express Native Power Management Events - PCI Express Advanced Error Reporting - PCI Express Capability Structure Control For further information visit the homepage of PLX Technology (www.plxtech.com) or Broadcom (www.broadcom.com). For further questions send an Email to support@ekf.de 2020-02-12 EKF