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Lê Minh Châu đang tìm kiếm từ khóa What is the process of starting a computer? được Update vào lúc : 2022-10-12 21:15:26 . Với phương châm chia sẻ Bí quyết Hướng dẫn trong nội dung bài viết một cách Chi Tiết 2022. Nếu sau khi đọc tài liệu vẫn ko hiểu thì hoàn toàn có thể lại Comments ở cuối bài để Ad lý giải và hướng dẫn lại nha.A computer without a program running is just an inert hunk of electronics. The first thing a computer has to do when it is turned on is to start up a special program called an operating system. The operating system’s job is to help other computer programs work by handling the messy details of controlling the computer’s hardware.
Nội dung chính- An overview of the boot process Functions of BIOSWhat are the 5 steps of starting a computer?How do you turn on a computer step by step?
An overview of the boot process
The boot process is something that happens every time you turn your computer on. You don’t really see it, because it happens so fast. You press the power button and come back a few sec (or minutes if on slow storage like HDD) later and Windows 10, or Windows 11, or whatever Operating System you use is all loaded.
The BIOS chip tells it to look in a fixed place, usually on the lowest-numbered hard disk (the boot disk) for a special program called a boot loader (under Linux the boot loader is called Grub or LILO). The boot loader is pulled into memory and started. The bootloader’s job is to start the real operating system.
Functions of BIOS
1. POST (Power On Self Test): The Power On Self Test happens each time you turn your computer on. It sounds complicated and that’s because it kind of is. Your computer does so much when it’s turned on and this is just part of that.
- It initializes the various hardware devices. It is an important process to ensure that all the devices operate smoothly without any conflicts. BIOSes following ACPI create tables describing the devices in the computer. The POST first checks the bios and then tests the CMOS RAM. If there is no problem with this then POST continues to check the CPU, hardware devices such as the Video Card, and the
secondary storage devices such as the Hard Drive, Floppy Drives, Zip Drive, or CD/DVD Drives. If some errors are found then an error message is displayed on the screen or a number of beeps are heard. These beeps are known as POST beep codes.
2. Master Boot Record: The Master Boot Record (MBR) is a special boot sector the beginning of the disk. The MBR contains the code that loads the rest of OS, known as bootloader. This
complicated process (called the Boot Process) starts with the POST (Power On Self Test) and ends when the Bios searches for the MBR on the Hard Drive, which is generally located in the first sector, first head, first cylinder (cylinder 0, head 0, sector 1).
A typical structure looks like this:
The bootstrap loader is stored in the computer’s EPROM, ROM, or another non-volatile memory. When the computer is turned on or restarted, it first performs the power-on-self-test, also known as POST. If the POST is successful and no issues are found, the bootstrap loader will load the operating system for the computer into memory. The computer will then be able to quickly access, load, and run the operating system.
3. init: init is the last step of the kernel boot sequence. It looks for the file /etc/inittab to see if there is an entry for
initdefault. It is used to determine the initial run level of the system. A run-level is used to decide the initial state of the operating system.
Some of the run levels are:
- Level 0: System Halt.Level 1: Single user mode.Level 2: Full multiuser mode without network.Level 3: Full multiuser mode with network.Level 4: user definable.Level
5: Full multiuser mode with network and X display manager.Level 6: Reboot.
The above design of init is called SysV- pronounced as System five. Several other implementations of init have been written now. Some of the popular implementations are systemd and upstart. Upstart is being used by ubuntu since 2006. More details of the upstart can be found here.
The next step of init is to start up various daemons that support networking and other services. X server daemon is one of the most important daemons. It manages the display, keyboard, and mouse. When X server daemon is started you see a Graphical Interface and a login screen is displayed.
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What are the 5 steps of starting a computer?
Although it is possible to break down the boot-up process using a highly detailed analytical methodology, many computer professionals consider the boot-up process to consist of five significant steps: power on, POST, load BIOS, operating system load, and transfer of control to the OS.How do you turn on a computer step by step?
How to turn on a computer. Step 1: Find the 'on' button. It probably looks like this (but might be square or oblong!):. Step 2: Push the button. On some computers, the button lights up when the computer is on. ... . Step 3: Now you need to log in.. Tải thêm tài liệu liên quan đến nội dung bài viết What is the process of starting a computer?