L13 - T13C - S1 – Boot Process

Legacy BIOS Boot Mode -- UEFI Mode

• Firmware

• Power On Self-Test (POST)

• Boot Loader

• When a computer starts, the ______ runs a ______ to verify that the system components are present and functioning correctly.

• It then identifies a boot device and passes control to the OS’s ______ process

Legacy BIOS Boot Method — Pt 1

• Firmware scans the disk identified as the boot device and

  • Reads the master boot record (MBR) in the first sector of the disk

• The MBR identifies the boot sector for the partition marked as active

• The boot sector loads the boot manager,  

  • Which for Windows is BOOTMGR.EXE 

• The boot manager reads information from the boot configuration data (BCD) file,

  • Which identifies OSs installed on the computer.

Legacy BIOS Boot Method — Pt 2

• Assuming there is only a single Windows installation

• The boot manager loads the Windows boot loader WINLOAD.EXE stored in the system root folder on the boot partition 

  • If more than 1 OS then boot manager shows a boot menu for user to select the installation to boot

• WINLOAD then loads

  • The kernel (NTOSKRNL.EXE),  

  • The hardware abstraction layer (HAL.DLL), and  

  • Boot device drivers.

• Control is then passed to the Kernel

  • Initializes and starts loading the required processes.

  • When complete, the WINLOGON process waits for the user to authenticate

True

True or False: BOOTMGR and the BCD are normally installed to a hidden System Reserved partition

UEFI Boot Mode Method

• After POST, the firmware reads the GUID partition table (GPT) on the boot device

• GPT identifies the EFI System Partition

  • Contains

    • EFI Boot Manager (BOOTMGFW.EFI)

    • Boot Configuration Data (BCD)

• BOOTMGFW.EFI reads the BCD to identify whether to show a boot menu and to find the location of WINLOAD.EFI.

  • From this point, the Windows boot loader continues the boot process by loading the kernel, as described previously

True

True or False: Each Windows installation has a subfolder under \EFI\Microsoft\ that contains

• BCD

• BOOTMGFW.EFI