Dual Booting NixOS and Windows
From NixOS Wiki
Revision as of 18:37, 29 May 2018 by Samueldr (talk | contribs) (→EFI + Grub: Fixes comment, the previous statement wasn't false, but may have been surprising when compared to the installation section of the manual)
MBR
All MBR bootloaders will need at least some configuration to chainload Windows.
MBR + Grub
When using MBR on your disk then you can configure grub chain-loading:
{
boot.loader.grub.enable = true;
boot.loader.grub.version = 2;
boot.loader.grub.device = "/dev/sda";
boot.loader.grub.extraEntries = ''
menuentry "Windows 7" {
chainloader (hd0,1)+1
}
'';
}
Source: https://www.reddit.com/r/NixOS/comments/31lx3i/windows_and_nixos_dual_boot/
EFI
After setting up a 256mb EFI Partition dualboot should work out of the box (at least for windows10)
Source: https://zimbatm.com/journal/2016/09/09/nixos-window-dual-boot/
EFI + Grub
systemd-boot can not load EFI binaries from other partitions, and a pre-exisitng EFI partition from a Windows install may be smaller than we would like our /boot partition to be. If we still want Windows and NixOS to use the same EFI partition, we can use GRUB instead.
Here we assume:
- the EFI partition has been mounted on /boot/efi
- $FS_UUID is the UUID of the EFI partition
- the boot.loader.systemd-boot.enable = true; line added to configuration.nix by nixos-generate-config has been removed
{ config, ... }:
{
boot.loader = {
efi = {
canTouchEfiVariables = true;
# assuming /boot is the mount point of the EFI partition in NixOS (as the installation section recommends).
efiSysMountPoint = "/boot";
};
grub = {
# despite what the configuration.nix manpage seems to indicate,
# as of release 17.09, setting device to "nodev" will still call
# `grub-install` if efiSupport is true
# (the devices list is not used by the EFI grub install,
# but must be set to some value in order to pass an assert in grub.nix)
devices = [ "nodev" ];
efiSupport = true;
enable = true;
# set $FS_UUID to the UUID of the EFI partition
extraEntries = ''
menuentry "Windows" {
insmod part_gpt
insmod fat
insmod search_fs_uuid
insmod chain
search --fs--uid --set=root $FS_UUID
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
'';
version = 2;
};
};
}
Sources:
- Arch Wiki GRUB article
- NixOS GRUB installer (check the code block beginning with # install EFI GRUB)