Notes and information about EKF SC3-LARGO UEFI/BIOS Firmware: ============================================================== 1) SC3-LARGO 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 SC3-LARGO describes this in detail: http://ekf.de/s/sc3/sc3_ug.pdf To bring the board back to working state the (red) ejector handle in front panel of SC3-LARGO handle must simply be opened for a short time (less than 4 seconds). Technical background: On EKF SC3-LARGO 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 SC3-LARGO 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 SC3-LARGO 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. For further questions send an Email to support@ekf.de 2020-02-12 EKF