Boot

This guide covers how to change what you boot into from both Windows and NixOS.

🔄 Methods to Change Boot Order

1. From NixOS (Recommended)

Using Keyboard Shortcuts

• Super+Ctrl+B: Show current boot information
• Super+Shift+B: List all boot entries
• Super+Alt+B: Show available boot commands

Using Terminal Commands

## Set next boot to NixOS
set-boot-nixos

## Set next boot to Windows
set-boot-windows

## Show current boot configuration
boot-info

## List all boot entries
list-boot-entries

Manual EFI Management

## List all boot entries
sudo efibootmgr

## Set next boot (one-time)
sudo efibootmgr --bootnext 0001  # Replace with boot number

## Change boot order permanently
sudo efibootmgr --bootorder 0001,0002,0003  # Replace with actual numbers

2. From Windows

Method 1: EasyBCD (Recommended)

1. Download EasyBCD (free for personal use)
2. Run as Administrator
3. Go to “Edit Boot Menu”
4. Reorder entries or set default
5. Click “Save Settings”

Method 2: bcdedit (Built-in)

1. Open Command Prompt as Administrator
2. View current entries:

   bcdedit /enum

3. Set default boot:

   bcdedit /default {identifier}

4. Set timeout:

   bcdedit /timeout 10

Method 3: System Configuration

1. Press Win+R, type msconfig
2. Go to “Boot” tab
3. Select desired OS and click “Set as default”
4. Adjust timeout if needed
5. Click “OK”

Method 4: UEFI/BIOS Setup

1. Restart your computer
2. Enter BIOS/UEFI (usually F2, F12, Del, or Esc)
3. Navigate to “Boot” or “Boot Order”
4. Reorder boot entries
5. Save and exit

3. From GRUB Menu (At Boot Time)

One-Time Selection

1. Restart computer
2. When GRUB menu appears, use arrow keys
3. Select desired OS
4. Press Enter to boot

Permanent Default

1. Boot into NixOS
2. Edit /etc/default/grub:

   GRUB_DEFAULT=2  # Set to Windows entry number
   GRUB_TIMEOUT=10  # Show menu for 10 seconds

3. Rebuild GRUB:

   sudo nixos-rebuild switch

🔧 Advanced Configuration

Custom GRUB Configuration

To permanently change boot order in NixOS:

## In your hardware-configuration.nix or a separate boot module
boot.loader.grub = {
  enable = true;
  efiSupport = true;
  useOSProber = true;
  default = 2;  # Set Windows as default (0-based index)
  timeout = 10;  # Show menu for 10 seconds

  extraEntries = ''
    menuentry "Windows 11" {
      insmod part_gpt
      insmod fat
      insmod chain
      search --file --set=root /EFI/Microsoft/Boot/bootmgfw.efi
      chainloader /EFI/Microsoft/Boot/bootmgfw.efi
    }
  '';
};

Network Boot Management

For remote boot management via SSH:

## From any machine with SSH access
ssh luxus@lea-ip "sudo set-boot-windows && sudo reboot"

## Or create a script for remote boot management
#!/bin/bash
case $1 in
  nixos) ssh luxus@lea-ip "sudo set-boot-nixos && sudo reboot" ;;
  windows) ssh luxus@lea-ip "sudo set-boot-windows && sudo reboot" ;;
  *) echo "Usage: $0 [nixos|windows]" ;;
esac

📱 Mobile Boot Control

Android App

1. Use Termux with SSH
2. Create aliases for boot commands
3. Execute remote boot commands

iOS Shortcut

1. Create Siri Shortcut
2. Add “Run SSH Script” action
3. Add boot management commands

🎯 Quick Reference

From NixOS

## Quick boot to Windows
set-boot-windows && sudo reboot

## Quick boot to NixOS (if Windows was default)
set-boot-nixos && sudo reboot

From Windows

## Quick boot to NixOS (requires admin)
bcdedit /default {identifier-for-nixos}
shutdown /r /t 0

🔍 Troubleshooting

GRUB Not Showing

1. Hold Shift while rebooting
2. Edit GRUB timeout:

   boot.loader.grub.timeout = 10;

3. Rebuild: sudo nixos-rebuild switch

EFI Boot Issues

## Check EFI variables
sudo efibootmgr -v

## Reset boot order to defaults
sudo efibootmgr --bootorder 0000,0001,0002,0003,0004

## Create missing boot entry
sudo efibootmgr --create --disk /dev/sda --part 1 --label "NixOS" --loader "\\EFI\\NixOS\\grubx64.efi"

Windows Boot Manager Issues

## Rebuild BCD
bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

## Reset to defaults
bcdedit /deletevalue {default} recoveryenabled
bcdedit /set {default} recoveryenabled Yes

🚀 Automation Scripts

Boot Toggle Script

#!/bin/bash
## Toggle between NixOS and Windows
if efibootmgr | grep -q "BootNext.*NixOS"; then
    set-boot-windows
    echo "Next boot: Windows"
else
    set-boot-nixos
    echo "Next boot: NixOS"
fi

Scheduled Boot

## Schedule boot to Windows at 6 PM daily
echo "0 18 * * * luxus /usr/bin/set-boot-windows" | sudo tee -a /etc/crontab

📋 Boot Entry Numbers

Typical boot entry pattern:

• 0000: NixOS
• 0001: Windows Boot Manager
• 0002: UEFI Settings
• 0003: Network Boot

Check your actual numbers with efibootmgr or boot-info.