Melina

Automated Kernel Fallback Shield for Arch Linux

Melina is a zero-configuration, automated fallback shield for Arch Linux systems using systemd-boot. It intercepts pacman kernel and system transactions, creating an isolated, bootable safety net before any destructive writes occur on your disk.

If a system crash, power outage, or fatal error occurs during a kernel update, your primary boot entries will corrupt. Melina ensures you always have a pristine, untouched Arch Linux {Melina} entry waiting in your boot menu to instantly recover your machine.

Architecture

Melina is designed with infrastructure-as-code principles and operates autonomously:

• Dynamic Detection: Automatically detects your boot architecture, fully supporting both Standard (discrete vmlinuz + initramfs) and UKI (Unified Kernel Image) deployments.
• ALPM Hook Integration: Uses pacman PreTransaction hooks. The backup occurs before pacman extracts the new kernel, guaranteeing the backup is made from a known-working state.
• Idempotent Execution: Reads storage capacity on the EFI System Partition (ESP) and aborts operations safely if space is insufficient.

Installation

Run the following bootstrap command to fetch and register the CLI globally on your system.

curl -sSL https://raw.githubusercontent.com/sluiys/melina/main/install.sh | sudo bash

After registering the command, initialize the infrastructure:

sudo melina init

Usage and CLI Commands

The tool is entirely managed via the melina CLI, which requires administrative privileges (sudo).

• "sudo melina init" --- Installs the bash engine, configures the pacman ALPM hooks, and triggers the first backup. Your system is now shielded.

• "sudo melina remove" --- Completely purges the tool from your system. It removes all isolated backup files, .conf entries, hooks, and executables, leaving the system in its original state.

• "sudo melina restore" --- The emergency recovery protocol. Use this strictly when your primary boot fails and you have booted into the {Melina} fallback entry. It rebuilds your primary boot binaries by delegating a clean installation to pacman.

Emergency Recovery Protocol

If your system crashes during an update and your primary Arch Linux boot option disappears or fails to boot:

• Reboot your machine.

• In the systemd-boot menu, select Arch Linux {Melina}.

• Once booted into the operational system, open your terminal.

  Execute the recovery command:

  sudo melina restore

  The CLI will temporarily disarm the safety hook, query the ALPM database for your core packages (e.g., linux, systemd, amd-ucode, mkinitcpio), force a clean pacman reinstallation to fix the broken binaries, and rearm the shield automatically.

Requirements

• Arch Linux (or Arch-based distributions)

• systemd-boot as the active bootloader

• Sufficient space on the EFI System Partition to duplicate your kernel/UKI files.