How to Regenerate Grub2 Config Files on Linux

By Eric Z Ma, Dec 23, 2015

Grub2 config file may need to be re-generated after changing Grub2 configurations such as configuration changes and setting default boot entries. The Grub2’s config file may be at different locations depending on your Linux distro and whether your Linux is booted in BIOS or UEFI mode. This makes regenerating Grub2 config file not easy for Linux users especially beginners. In this post, I will introduce a way that should be portable and easy to use. » Read more

Configuring Linux Kernel Video Mode for 32-bit and 16-bit Boot Protocols

By Eric Z Ma, Apr 29, 2015

The Linux kernel has a generic driver for a graphic framebuffer named vesafb on intel boxes. It provides a nice large console for most of modern displays. Setting VESA modes for Linux kernel with 32-bit and 16-bit boot protocol are different. We introduce both methods here. Linux kernel with 32-bit boot protocolFor machine with some new BIOS other than legacy BIOS, such as EFI, LinuxBIOS, etc, and kexec, the 16-bit real mode setup code in kernel based on legacy BIOS can not be used, so a 32-bit boot protocol needs to be defined. » Read more

Setting Default Entry in Grub2 and Grub

By Eric Z Ma, Mar 20, 2017

Linux booting is usually controlled by Grub or the new Grub2. Setting the default booting entry is a frequent operations. Here, we introduce how to set the default entry in Grub2 and Grub. Setting the default booting entry in grub2 Note1: With some version of grub2, the grub2-set-default method and the script below may not work. You can check the “Setting default boot entry for grub2 in /etc/default/grub” method below. » Read more