Ahmed x86 | GRUB Fixer

About the Project

GRUB Fixer (V27 - The "Bulletproof" Update) takes system recovery to the absolute limit. It is an automated, bulletproof Bash script designed to repair the GRUB bootloader on both UEFI and Legacy BIOS GNU/Linux systems. V27 solidifies the engine with extreme error handling, strict cleanup traps, and absolute execution safety. This builds upon the Modular Architecture (V26), VM Polishing (V25), Backend API (V24), Security Hardening (V23), Secure Boot Support (V22), and LUKS Encryption (V21) of previous versions.

✨ New in V27: Absolute Safety! Implemented a strict trap engine to automatically unmount and clean up the system on errors, plus global input validation and download integrity verification.

🛡️ The Bulletproof Update (V27)

Absolute Safety (Trap Engine): A global trap system guarantees that your system is never left in an unstable state, safely unmounting all partitions before exiting on success, failure, or interruption.
Network Interruption Immunity: Modules download to temporary files with strict HTTP checks, preventing incomplete code execution during connection drops.
Global Input Validation: Robust, pipe-safe boolean engine forces valid y/n answers across all interactive prompts, eliminating typos.

🧩 The Modular Update (V26)

Architectural Overhaul: The monolith script is completely deconstructed into a sleek, modular engine (api, ui, crypto, core_scan, secureboot).
Smart Module Loader: Intelligently detects execution context, sourcing local files or downloading modules on-the-fly to a temporary directory.

✨ The Polishing Update (V25)

VM & VirtIO Precision: Fixed Legacy BIOS disk extraction failures in virtual environments by implementing a smart Regex fallback.
Btrfs Hardening: Added failsafe checks for empty subvolume definitions in fstab parsing.

🔌 The Backend API Update (V24)

JSON Endpoints for GUIs: Designed to be the brain behind graphical interfaces (--sys-info, --json-scan).
Explicit Execution Mapping: Bypasses all interactive logic when instructed by a frontend GUI via --map-std or --map-btrfs.
Headless Worker: Operates flawlessly in the background, executing precise mounts, LUKS unlocks, and repairs.

🔒 The Security Hardening Update (V23)

Anti-Shoulder Surfing: LUKS password input is now completely hidden (read -s).
Dynamic MOK OTP Generation: Replaced hardcoded passwords with a 12-character random One-Time Password.
Failsafe Config Backups: Creates a timestamped backup of /etc/default/grub before modification.

🛡️ The Secure Boot Update (V22)

Smart State Detection: Utilizes mokutil --sb-state to check if Secure Boot is enforced.
Dynamic Shim Routing: Forces --uefi-secure-boot on Debian/Ubuntu systems to utilize Microsoft-signed shim binaries.
Arch Linux sbctl Integration: Detects custom keys and attempts automatic sbctl sign.

🔐 The LUKS Encryption Update (V21)

Early LUKS Detection: Scans for crypto_LUKS partitions before the Deep Scan Engine starts.
LVM Auto-Activation: Automatically runs vgchange -ay to expose hidden Logical Volumes.
Auto-Cryptodisk Injection: Appends GRUB_ENABLE_CRYPTODISK=y to ensure the repaired system prompts for a password.

🩺 The Health Check Update (V20)

Smart Dependency Resolution: Auto-detects missing crucial packages (grub, os-prober, efibootmgr, cryptsetup, mokutil).
Multi-Package Manager Support: Dynamically utilizes pacman, apt-get, dnf, or zypper.

🌐 The Universal Update (V19)

RedHat/Fedora Family Support: Full compatibility with Fedora, RHEL, CentOS, Rocky, and AlmaLinux.
Dynamic Command Routing: Automatically switches to RedHat-specific grub2-install / grub2-mkconfig.

🚩 CLI Flags & API Reference

Bypass prompts, enable headless automation, or integrate with graphical frontends:

--sys-info: Return basic system information as JSON.
--json-scan: Stealth scan outputting partition layout as JSON.
--map-std "<mapping>": Explicit partition layout for standard filesystems.
--map-btrfs "<mapping>": Explicit partition layout for Btrfs setups.
-env l or -env live: Force the script to assume a Live Environment.
-env h or -env host: Force the script to assume a Real Machine environment.
-auto: Bypasses all confirmation prompts (y/n) and executes the repair instantly.
--version or -v: Print the current version and exit.

🛠️ Usage

Run the "Ultimate Rescue Weapon" directly from your terminal:

Option 1: Quick One-Liner (Interactive Mode)

The classic, smart, and unified interactive experience:

curl -sL https://raw.githubusercontent.com/ahmed-x86/grub-fixer/main/grub-fixer.sh | sudo bash

Option 2: Fully Automated (Zero-Interaction Mode) 💥

Skip all questions and let the script fix GRUB silently based on auto-detection (perfect for Live USBs):

curl -sL https://raw.githubusercontent.com/ahmed-x86/grub-fixer/main/grub-fixer.sh | sudo bash -s -- -env l -auto

Option 3: Manual Download

curl -O https://raw.githubusercontent.com/ahmed-x86/grub-fixer/main/grub-fixer.sh
chmod +x grub-fixer.sh
sudo ./grub-fixer.sh [FLAGS]

📜 Version History

Click to view full version history

Version	Major Changes
V1	Basic manual-like chroot logic for GRUB repair.
V2	Added input validation (checks if partition exists) and loops for user input.
V3	Added /mnt cleanup (umount -R) before starting to prevent mount conflicts.
V4	Added 'set -e' for safety, forced Root partition input, OS detection.
V5	Added '--removable' to fix VM/NVRAM issues, and TTY Pipeline support.
V6	Added Auto-Detection using lsblk FSTYPE without mounting.
V7	Added dynamic support for mounting custom volumes (e.g., /home, /var).
V8	Added Root Validation, System Logging, and Smart EFI Detection.
V9	Added dynamic Btrfs subvolumes support with smart routing.
V10	Bulletproof Btrfs loop (forced y/n), fixed Archinstall /boot vs /boot/efi trap.
V11	Zero-Interaction Mode (fstab parser), 3-Tier Fallback System.
V12	Added Legacy BIOS (i386-pc) support, auto-detection, and Target Disk extraction.
V13	Added OS Prober support to automatically detect dual-boot systems (e.g., Windows).
V14	Added Dynamic Execution Timer with gamer-style human responses (The Speedrun Update).
V15	Added Universal UEFI Support (32-bit/i386-efi) with dynamic bitness detection.
V16	Added In-Situ (Local) Mode to repair GRUB directly from the running system without Live USB/chroot.
V17	Deep Scan Engine, Kernel Cmdline Detection, & Unified UX Prompt.
V18	Added CLI Flags (--version, -env l/h, -auto) for complete Zero-Interaction Automation.
V19	Added universal support for RedHat/Fedora/CentOS family (dynamic grub2 commands & paths).
V20	Chroot Health Check - Auto-detects and installs missing GRUB/EFI packages with DNS resolv support.
V21	LUKS & LVM Encryption Support - Auto-detects, unlocks (visible password), and configures GRUB_ENABLE_CRYPTODISK.
V22	Secure Boot & Shim Integration - Auto-detects Secure Boot, handles shim-signed, and MOK Enrollment.
V23	Security Hardening & Bug Fixes - Dynamic MOK OTP, hidden LUKS passwords, config backups, and environment isolation.
V24	The "Backend API" Update - Added JSON Endpoints (--sys-info, --json-scan) and explicit mapping for GUI integration.
V25	The "Polishing" Update - VM/VirtIO Regex Fallback and Btrfs Hardening.
V26	The "Modular" Update - Completely refactored the monolith script into a modular architecture with on-the-fly loading.
V27	Current: The "Bulletproof" Update - Strict trap cleanup engine, download integrity verification, and global input validation.

📋 System Requirements

OS Families: Arch Linux, Debian/Ubuntu, RedHat/Fedora, SUSE, and derivatives.
Architecture: UEFI (x86_64/i386) or Legacy BIOS (i386-pc).
Privileges: Sudo/Root access required.
Filesystems: Ext4, Btrfs, XFS, LUKS, LVM2.
Secure Boot: Fully supported (Requires Motherboard MOK Enrollment via OTP).

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