GRUB2 Quick Start
This article provides information on how to get up and running with grub:2 in the simplest configurations. For more comprehensive information, see GRUB2.
Gentoo GRUB Legacy (0.97) to GRUB2 Migration Guide
The guide is available at: http://www.gentoo.org/doc/en/grub2-migration.xml
The sys-boot/grub package is slotted; both grub-0.97 and grub-2.00 may be installed at the same time.
If you want to install grub-0.97 or keep it installed after an upgrade, call emerge with the "0" slot on the end of the package atom. This will add sys-boot/grub:0 to your world file. For example:
Only one version may be installed in your MBR at one time.
Installing the software
Set GRUB_PLATFORMS in make.conf (optional). If unset, grub will guess which platform you want. It guesses "pc" for x86/amd64.
Installing a bootable image
Mount your /boot volume if you have one.
If you are using an EFI platform, mount your EFI system volume at /boot/efi. This should be a FAT volume containing an EFI subdirectory.
Run the grub2-install utility to copy the relevant files to /boot/grub. On the PC platform, this also installs a boot image to the master boot record (MBR) or a partition's boot sector.
grub2-install accepts a --target option to specify which CPU/Platform to install. If unspecified, grub2-install will make a guess; on amd64/x86 it will use "i386-pc" by default.
Installing to the MBR:
Installing to a partition (not recommended):
Installing on EFI:
GRUB2 is traditionally configured by using the grub2-mkconfig program to generate a config file.
grub2-mkconfig generates the config file based on template sections in /etc/grub.d. The default templates should cover most common boot setups.
The behavior of these templates may be controlled by setting variables in /etc/default/grub. See the GRUB manual for reference.
In order for grub2-mkconfig to detect your Linux kernel(s), they must be named vmlinuz-version or kernel-version. For example:
If you use an initramfs, it should be named initramfs-version.img or initrd-version.img. File names generated by genkernel will also work.
Generate the grub.cfg file:
Silent Kernel Decompression
To silence kernel decompression make your line in /etc/default/grub look like this.
to boot systemd with grub2 make your line look like this
Loading another operating system
grub2-mkconfig can generate a configuration to load other operating systems. This requires the sys-boot/os-prober package.
To boot Windows, you should also install sys-fs/ntfs3g to allow grub2-mkconfig to probe NTFS filesystems.
Instead of using
grub2-mkconfig, a typical simple
grub.conf can easily be converted to be suitable for use in