Ad
related to: lenovo boot device selection key ideas page 1 free
Search results
Results From The WOW.Com Content Network
A modern PC is configured to attempt to boot from various devices in a certain order. If a computer is not booting from the device desired, such as the floppy drive, the user may have to enter the BIOS Setup function by pressing a special key when the computer is first turned on (such as Delete, F1, F2, F10 or F12), and then changing the boot order. [6]
When Secure Boot is enabled, it is initially placed in "setup" mode, which allows a public key known as the "platform key" (PK) to be written to the firmware. Once the key is written, Secure Boot enters "User" mode, where only UEFI drivers and OS boot loaders signed with the platform key can be loaded by the firmware.
The boot loader is responsible for accessing the file system on the boot drive, starting ntoskrnl.exe, and loading boot-time device drivers into memory. Once all the boot and system drivers have been loaded, the kernel starts the session manager (smss.exe), which begins the login process.
The boot code in the VBR can assume that the BIOS has set up its data structures and interrupts and initialized the hardware. The code should not assume more than 32 KB of memory to be present for fail-safe operation; [1] if it needs more memory it should query INT 12h for it, since other pre-boot code (such as f.e. BIOS extension overlays, encryption systems, or remote bootstrap loaders) may ...
A modern PC with a bus rate of around 1 GHz and a 32-bit bus might be 2000x or even 5000x faster, but might have many more gigabytes of memory. With boot times more of a concern now than in the 1980s, the 30- to 60-second memory test adds undesirable delay for a benefit of confidence that is not perceived to be worth that cost by most users.
Note: The column MBR (Master Boot Record) refers to whether or not the boot loader can be stored in the first sector of a mass storage device. The column VBR (Volume Boot Record) refers to the ability of the boot loader to be stored in the first sector of any partition on a mass storage device.
In an OS/2 dual-boot configuration, the C drive can contain both DOS and OS/2. The user issues the BOOT command [1] from the DOS or OS/2 command line to do the necessary copy, move and rename operations and then reboot to the specified system on C:. Other systems provide similar mechanisms for alternate systems on the same logical drive.
coreboot, formerly known as LinuxBIOS, [5] is a software project aimed at replacing proprietary firmware (BIOS or UEFI) found in most computers with a lightweight firmware designed to perform only the minimum number of tasks necessary to load and run a modern 32-bit or 64-bit operating system.