Grub not shown on external screen after installing Arch Linux on old laptop

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Title: Grub not showing up in BIOS/UEFI on Arch Linux old laptop

Introduction

Recently, you downloaded Arch Linux and installed it on your old laptop using the Arch Install Script (Arch Install SH). You chose Grub as your bootloader, but you're not sure if there's a problem with BIOS or UEFI, as Grub doesn't show up in the boot menu.

Detailed Context

In this case, it's essential to determine if your system is using BIOS or UEFI, as the boot process and configuration can vary significantly between the two. Here's a general overview of the steps you can follow:

1. Check your system type: To find out whether your system is using BIOS or UEFI, restart your computer and enter the BIOS/UEFI settings by pressing the appropriate key (usually F2, F10, F12, Esc, or Del). Look for the boot mode settings, and you should see either UEFI or Legacy/CSM. If you see UEFI, your system is using UEFI, and if you see Legacy/CSM, your system is using BIOS.

2. Check Grub configuration: If your system is using UEFI, you should configure Grub to use the UEFI bootloader. To do this, edit the /etc/default/grub file and change the GRUB_TIMEOUT, GRUB_CMDLINE_LINUX, and GRUB_INIT_FD settings. Then, run grub-mkconfig -o /boot/grub/grub.cfg to generate the Grub configuration file.

3. Install OS-prober: If Grub still doesn't show up in the UEFI boot menu, install the os-prober package to automatically detect your operating system and add it to the UEFI boot menu. After installing os-prober, run update-grub to regenerate the Grub configuration.

4. Check the boot order: Make sure that your Arch Linux entry is at the top of the boot order in the UEFI settings.

5. Check for EFI system partition: Ensure that you have an EFI system partition (usually /boot/efi or /boot/EFI). If it doesn't exist, create one using the mkfs.fat command and mount it at /boot/efi or /boot/EFI.

Code Blocks

Here's an example of how to edit the /etc/default/grub file:

# /etc/default/grub

GRUB_TIMEOUT=5
GRUB_CMDLINE_LINUX="quiet splash"
GRUB_INIT_FD="/boot/grub/grubenv"

References

• ArchWiki: Grub
• ArchWiki: UEFI
• ArchWiki: os-prober

Summary

To resolve the issue of Grub not showing up in the BIOS/UEFI boot menu on your Arch Linux old laptop, follow the steps outlined above to configure Grub, install os-prober, check the boot order, and ensure that you have an EFI system partition. If you still encounter problems, consider consulting the Arch Linux forums or seeking help from experienced Arch Linux users.