Dual Booting: Enter Legacy BIOS Directly Using GRUB?
Dual booting is the process of installing two or more operating systems on a single computer, allowing users to choose which one to use at startup. One popular combination is running Windows and Linux on the same machine. However, sometimes users may encounter issues when trying to enter the Legacy BIOS to boot into Linux directly, instead of going through the Windows bootloader. This article will explore the possibility of entering the Legacy BIOS directly using GRUB and provide detailed instructions for doing so.
Understanding the Boot Process
To understand the issue at hand, it's essential to know how the boot process works. When a computer starts up, the BIOS (Basic Input/Output System) runs a power-on self-test (POST) and then searches for a boot device. The boot device is typically the primary hard drive, but it can also be a USB drive or a CD/DVD drive. Once the BIOS finds a boot device, it loads the bootloader, which then loads the operating system.
In a dual-boot setup with Windows and Linux, the default bootloader is usually the Windows bootloader. When the user wants to boot into Linux, they must first select the Linux option from the Windows bootloader. However, some users may prefer to bypass the Windows bootloader and boot directly into GRUB, the bootloader for Linux.
Entering the Legacy BIOS Directly
To enter the Legacy BIOS directly and modify the boot order, users typically need to press a specific key during the boot process, such as F2, F10, or Del. However, some computers may not provide this option, or the key may vary depending on the manufacturer. In such cases, users can try accessing the BIOS through the system's firmware settings.
To access the firmware settings, users can follow these steps:
- Restart the computer.
- Press the Windows key + I to open the Settings app.
- Click on Update & Security.
- Click on Recovery in the left-hand menu.
- Under Advanced startup, click on Restart now.
- In the Choose an option screen, click on Troubleshoot.
- Click on Advanced options.
- Click on UEFI Firmware Settings.
- Click on Restart.
Once in the BIOS, users can modify the boot order to prioritize the Linux bootloader over the Windows bootloader. However, this may not always be possible, especially if the computer's firmware is locked down or if the BIOS does not provide this option.
Using GRUB to Boot Directly into Linux
Another option is to use GRUB to boot directly into Linux. This can be done by editing the GRUB configuration file, typically located at /etc/default/grub. Users can open the file with a text editor such as nano or vim and modify the GRUB_TIMEOUT and GRUB_DEFAULT variables.
GRUB_TIMEOUT=0
GRUB_DEFAULT=0
The GRUB_TIMEOUT variable controls how long the GRUB menu is displayed before the default option is automatically selected. Setting it to 0 will disable the timeout and immediately select the default option. The GRUB_DEFAULT variable specifies the index of the default option. In this example, the first option (index 0) is selected.
After modifying the GRUB configuration file, users need to update the GRUB bootloader by running the following command:
sudo update-grub
This will generate a new GRUB configuration file and update the bootloader. The next time the computer starts up, it will boot directly into Linux without displaying the GRUB menu or going through the Windows bootloader.
References
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Type: Article
Title: "How to Boot Directly into Linux from GRUB"
Author: Jack Wallen
Publication: Linux.com
Date: November 14, 2019 -
Type: Book
Title: "Dual Booting: Install Windows and Linux on the Same