Configuring Grub2 to Use the Custom Image

Oct 13, 2025 by wbrum.org 47 views

Introduction

When setting up a Linux system with full disk encryption using LUKS, it's essential to ensure that the keyboard layout is suitable for entering the LUKS passphrase. In this article, we'll explore how to change the keyboard disposition for LUKS passphrase entry using Grub2 on Slackware 15.1.

Disk Partitions

Before we dive into the process, let's take a look at the disk partitions on our system. We can use the lsblk command to get an overview of the disk layout.

# lsblk
NAME               MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                  8:0    0  1.8T  0 disk
|-sda1               8:1    0   512M  0 part /boot
|-sda2               8:2    0  1.8T  0 part
  |-cryptlvm        253:0    0  1.8T  0 crypt /mnt
    |-lvm-root     253:1    0  1.8T  0 lvm  /
    |-lvm-swap     253:2    0   16G  0 lvm  [SWAP]

In this example, we have a single disk /dev/sda with two partitions: /dev/sda1 and /dev/sda2. The /dev/sda2 partition is encrypted using LUKS and contains a logical volume group (cryptlvm) with two logical volumes: lvm-root and lvm-swap.

Changing Keyboard Disposition using Grub-mkimage

To change the keyboard disposition for LUKS passphrase entry, we'll use the grub-mkimage command. This command allows us to create a custom Grub2 image that includes the necessary modules for keyboard layout support.

First, we need to install the grub-mkimage package on our system. On Slackware 15.1, we can install it using the following command:

# slackpkg install grub-mkimage

Once installed, we can use the grub-mkimage command to create a custom Grub2 image. We'll use the following command to create an image that includes the keymap module for keyboard layout support:

# grub-mkimage -o /boot/grub2/custom.img -p /boot/grub2 -m /boot/grub2/grub.cfg -c -d /boot/grub2/i386-pc -O i386-pc keymap

This command creates a custom Grub2 image (custom.img) that includes the keymap module for keyboard layout support. The -p option specifies the path to the Grub2 configuration file, and the -m option specifies the path to the Grub2 menu configuration file.

Configuring Grub2 to Use the Custom Image

To use the custom Grub2 image, we need to configure Grub2 to load it instead of the default image. We can do this by editing the Grub2 configuration file (/boot/grub2/grub.cfg) and adding the following line:

set prefix=(hd0,1)/boot/grub2
set root=(hd0,1)
insmod keymap

This code sets the prefix to the /boot/grub2 directory, sets the root device to the first partition on the first disk, and loads the keymap module.

Testing the Custom Image

To test the custom Grub2 image, we can reboot our system and enter the Grub2 menu. We should see the custom image loaded instead of the default image. We can then select the custom image and enter the LUKS passphrase using the new keyboard layout.

Conclusion

In this article, we've explored how to change the keyboard disposition for LUKS passphrase entry using Grub2 on Slackware 15.1. We've created a custom Grub2 image using the grub-mkimage command and configured Grub2 to load it instead of the default image. With this custom image, we can enter the LUKS passphrase using the new keyboard layout.

Troubleshooting

If you encounter any issues while following this guide, here are some troubleshooting tips:

Make sure you've installed the grub-mkimage package correctly.
Check the Grub2 configuration file (/boot/grub2/grub.cfg) for any errors or typos.
Verify that the custom image is loaded correctly by checking the Grub2 menu.
If you're still having issues, try booting your system in single-user mode and checking the system logs for any errors.

Additional Resources

For more information on Grub2 and LUKS, here are some additional resources:

The Grub2 documentation: https://www.gnu.org/software/grub/manual/grub.html
The LUKS documentation: https://gitlab.com/cryptsetup/cryptsetup/wikis/LUKS
The Slackware documentation: https://docs.slackware.com/
Grub2, Change Keyboard Disposition for LUKS Passphrase using Grub-mkimage: Q&A ====================================================================

Introduction

In our previous article, we explored how to change the keyboard disposition for LUKS passphrase entry using Grub2 on Slackware 15.1. In this article, we'll answer some frequently asked questions (FAQs) related to this topic.

Q: What is Grub2?

A: Grub2 is a boot loader that allows you to choose which operating system to boot from a menu. It's a replacement for the older Grub and is widely used on Linux systems.

Q: What is LUKS?

A: LUKS (Linux Unified Key Setup) is a disk encryption system that allows you to encrypt your disk partitions. It's a popular choice for encrypting Linux systems.

Q: Why do I need to change the keyboard disposition for LUKS passphrase entry?

A: When you encrypt your disk partitions using LUKS, you need to enter a passphrase to unlock the encrypted partitions. If your keyboard layout is not set correctly, you may not be able to enter the passphrase correctly, which can prevent you from booting your system.

Q: How do I create a custom Grub2 image using grub-mkimage?

A: To create a custom Grub2 image using grub-mkimage, you need to run the following command:

# grub-mkimage -o /boot/grub2/custom.img -p /boot/grub2 -m /boot/grub2/grub.cfg -c -d /boot/grub2/i386-pc -O i386-pc keymap

This command creates a custom Grub2 image (custom.img) that includes the keymap module for keyboard layout support.

Q: How do I configure Grub2 to use the custom image?

A: To configure Grub2 to use the custom image, you need to edit the Grub2 configuration file (/boot/grub2/grub.cfg) and add the following lines:

set prefix=(hd0,1)/boot/grub2
set root=(hd0,1)
insmod keymap

This code sets the prefix to the /boot/grub2 directory, sets the root device to the first partition on the first disk, and loads the keymap module.

Q: How do I test the custom image?

A: To test the custom image, you need to reboot your system and enter the Grub2 menu. You should see the custom image loaded instead of the default image. You can then select the custom image and enter the LUKS passphrase using the new keyboard layout.

Q: What are some common issues that I may encounter while following this guide?

A: Some common issues that you may encounter while following this guide include:

Installing the grub-mkimage package incorrectly
Editing the Grub2 configuration file incorrectly
Loading the custom image incorrectly
Entering the LUKS passphrase incorrectly

Q: Where can I find more information on Grub2 and LUKS?

A: You can find more information on Grub2 and LUKS on the following websites:

The Grub2 documentation: https://www.gnu.org/software/grub/manual/grub.html
The LUKS documentation: https://gitlab.com/cryptsetup/cryptsetup/wikis/LUKS
The Slackware documentation: https://docs.slackware.com/

Conclusion

In this article, we've answered some frequently asked questions (FAQs) related to changing the keyboard disposition for LUKS passphrase entry using Grub2 on Slackware 15.1. We hope that this article has been helpful in answering your questions and providing you with a better understanding of this topic.