grub_nvme_repair

.sh

#!/bin/bash

# GRUB Repair Script for NVMe Disk (After BIOS Update)
# This script repairs GRUB bootloader after BIOS updates that break Linux boot
# Usage: Run this from a Kali Linux Live USB

# Color codes
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m' # No Color

echo -e "${CYAN}==========================================${NC}"
echo -e "${CYAN}GRUB Repair Script for NVMe Disk${NC}"
echo -e "${CYAN}==========================================${NC}"
echo ""

# Check if running as root
if [ "$EUID" -ne 0 ]; then 
    echo -e "${RED}ERROR: Please run as root (use sudo)${NC}"
    exit 1
fi

# Step 1: Identify partitions
echo -e "${BLUE}[Step 1] Identifying disk partitions...${NC}"
echo ""
lsblk -f
echo ""
echo -e "${YELLOW}Look for your Kali Linux partition (usually ext4 on nvme0n1)${NC}"
echo ""

# Get user input for partitions
read -p "Enter your Kali ROOT partition (e.g., nvme0n1p3): " ROOT_PARTITION
read -p "Enter your EFI partition (usually nvme0n1p1): " EFI_PARTITION

# Validate input
if [ -z "$ROOT_PARTITION" ] || [ -z "$EFI_PARTITION" ]; then
    echo -e "${RED}ERROR: Partitions cannot be empty${NC}"
    exit 1
fi

# Extract disk name (e.g., nvme0n1 from nvme0n1p3)
DISK_NAME=$(echo $ROOT_PARTITION | sed 's/p[0-9]*$//')

echo ""
echo -e "${CYAN}Configuration:${NC}"
echo -e "  Root partition: ${GREEN}/dev/$ROOT_PARTITION${NC}"
echo -e "  EFI partition:  ${GREEN}/dev/$EFI_PARTITION${NC}"
echo -e "  Disk:           ${GREEN}/dev/$DISK_NAME${NC}"
echo ""
read -p "Is this correct? (y/n): " CONFIRM

if [ "$CONFIRM" != "y" ] && [ "$CONFIRM" != "Y" ]; then
    echo -e "${YELLOW}Aborted by user${NC}"
    exit 1
fi

# Step 2: Mount partitions
echo ""
echo -e "${BLUE}[Step 2] Mounting partitions...${NC}"

umount -R /mnt 2>/dev/null  # Unmount if already mounted

mount /dev/$ROOT_PARTITION /mnt
if [ $? -ne 0 ]; then
    echo -e "${RED}ERROR: Failed to mount root partition${NC}"
    exit 1
fi
echo -e "${GREEN}✓ Mounted root partition${NC}"

# Check if /boot/efi exists in the root partition
if [ ! -d /mnt/boot/efi ]; then
    mkdir -p /mnt/boot/efi
    echo -e "${GREEN}✓ Created /boot/efi directory${NC}"
fi

mount /dev/$EFI_PARTITION /mnt/boot/efi
if [ $? -ne 0 ]; then
    echo -e "${RED}ERROR: Failed to mount EFI partition${NC}"
    umount /mnt
    exit 1
fi
echo -e "${GREEN}✓ Mounted EFI partition${NC}"

# Mount system directories
mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
echo -e "${GREEN}✓ Mounted system directories${NC}"

# Step 3: Chroot and repair GRUB
echo ""
echo -e "${BLUE}[Step 3] Entering chroot environment and repairing GRUB...${NC}"
echo ""

# Create a script to run inside chroot
cat > /mnt/tmp/repair_grub.sh << 'CHROOT_SCRIPT'
#!/bin/bash

# Color codes for chroot
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

echo -e "${CYAN}Inside chroot environment...${NC}"
echo ""

# Check if grub directory exists
if [ ! -d /boot/grub ]; then
    echo -e "${YELLOW}Creating /boot/grub directory...${NC}"
    mkdir -p /boot/grub
fi

# Check if grub binaries exist
if [ ! -f /usr/sbin/grub-install ]; then
    echo -e "${YELLOW}WARNING: GRUB packages not found!${NC}"
    echo "Attempting to reinstall (requires internet)..."
    apt update
    apt install -y --reinstall grub-efi-amd64 grub-common grub2-common
fi

# Install GRUB
echo -e "${BLUE}Installing GRUB to disk...${NC}"
DISK_NAME_CHROOT=$(echo $ROOT_PARTITION | sed 's/p[0-9]*$//')
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=kali --force /dev/$DISK_NAME_CHROOT

if [ $? -ne 0 ]; then
    echo -e "${YELLOW}WARNING: grub-install reported issues (this might be normal in Live USB)${NC}"
fi

# Generate GRUB configuration
echo ""
echo -e "${BLUE}Generating GRUB configuration...${NC}"
grub-mkconfig -o /boot/grub/grub.cfg

if [ $? -eq 0 ] && [ -f /boot/grub/grub.cfg ]; then
    echo -e "${GREEN}✓ GRUB configuration created successfully${NC}"
    echo ""
    echo -e "Config file size: ${GREEN}$(du -h /boot/grub/grub.cfg | cut -f1)${NC}"
else
    echo -e "${RED}ERROR: Failed to create GRUB configuration${NC}"
    exit 1
fi

# Update initramfs
echo ""
echo -e "${BLUE}Updating initramfs...${NC}"
update-initramfs -u -k all

echo ""
echo -e "${GREEN}✓ GRUB repair completed inside chroot${NC}"

CHROOT_SCRIPT

chmod +x /mnt/tmp/repair_grub.sh

# Export the ROOT_PARTITION variable so it's available in chroot
export ROOT_PARTITION

# Execute the script inside chroot
chroot /mnt /bin/bash -c "ROOT_PARTITION=$ROOT_PARTITION /tmp/repair_grub.sh"

CHROOT_EXIT_CODE=$?

# Step 4: Create fallback boot entries
echo ""
echo -e "${BLUE}[Step 4] Creating fallback EFI boot entries...${NC}"

# Ensure Boot folder exists with fallback bootloader
mkdir -p /mnt/boot/efi/EFI/Boot

if [ -f /mnt/boot/efi/EFI/kali/grubx64.efi ]; then
    cp /mnt/boot/efi/EFI/kali/grubx64.efi /mnt/boot/efi/EFI/Boot/bootx64.efi
    echo -e "${GREEN}✓ Created fallback bootloader${NC}"
elif [ -f /mnt/boot/efi/EFI/debian/grubx64.efi ]; then
    cp /mnt/boot/efi/EFI/debian/grubx64.efi /mnt/boot/efi/EFI/Boot/bootx64.efi
    echo -e "${GREEN}✓ Created fallback bootloader from debian${NC}"
fi

# Step 5: Install and use efibootmgr
echo ""
echo -e "${BLUE}[Step 5] Installing efibootmgr and registering EFI boot entry...${NC}"

# Check if efibootmgr is installed
if ! command -v efibootmgr &> /dev/null; then
    echo -e "${YELLOW}Installing efibootmgr...${NC}"
    
    # Check if we have internet connection
    if ping -c 1 8.8.8.8 &> /dev/null; then
        apt update
        apt install -y efibootmgr
        
        if [ $? -eq 0 ]; then
            echo -e "${GREEN}✓ efibootmgr installed successfully${NC}"
        else
            echo -e "${YELLOW}⚠ Failed to install efibootmgr (no internet or repository issue)${NC}"
            echo "  You may need to manually set boot order in BIOS"
        fi
    else
        echo -e "${YELLOW}⚠ No internet connection - cannot install efibootmgr${NC}"
        echo -e "  Please connect to internet ${CYAN}(nmtui for WiFi)${NC} and run script again"
        echo "  Or manually set boot order in BIOS"
    fi
fi

# Use efibootmgr if available
if command -v efibootmgr &> /dev/null; then
    echo ""
    echo -e "${CYAN}Current boot entries:${NC}"
    efibootmgr -v
    echo ""
    
    # Extract partition number from EFI_PARTITION
    PART_NUM=$(echo $EFI_PARTITION | grep -o '[0-9]*$')
    
    # Add Kali boot entry
    echo -e "${BLUE}Adding Kali Linux boot entry...${NC}"
    efibootmgr -c -d /dev/$DISK_NAME -p $PART_NUM -L "Kali Linux" -l "\\EFI\\kali\\grubx64.efi"
    
    if [ $? -eq 0 ]; then
        echo -e "${GREEN}✓ EFI boot entry registered${NC}"
        echo ""
        echo -e "${CYAN}Updated boot entries:${NC}"
        efibootmgr -v
    else
        echo -e "${YELLOW}⚠ Failed to register EFI boot entry${NC}"
        echo "  This is normal in some Live USB environments"
    fi
else
    echo -e "${YELLOW}⚠ efibootmgr not available${NC}"
    echo "  You may need to manually set boot order in BIOS"
fi

# Step 6: Cleanup
echo ""
echo -e "${BLUE}[Step 6] Cleaning up...${NC}"

rm -f /mnt/tmp/repair_grub.sh

umount /mnt/boot/efi
umount /mnt/dev
umount /mnt/proc
umount /mnt/sys
umount /mnt

echo -e "${GREEN}✓ All partitions unmounted${NC}"

# Final instructions
echo ""
echo -e "${CYAN}==========================================${NC}"
echo -e "${GREEN}GRUB Repair Complete!${NC}"
echo -e "${CYAN}==========================================${NC}"
echo ""
echo -e "${YELLOW}Next steps:${NC}"
echo -e "1. Reboot your system: ${CYAN}sudo reboot${NC}"
echo -e "2. Enter BIOS ${CYAN}(press F2 during boot on Acer Nitro)${NC}"
echo "3. Check these settings:"
echo -e "   - Boot Mode: ${GREEN}UEFI${NC} (not Legacy/CSM)"
echo -e "   - Secure Boot: ${GREEN}Disabled${NC}"
echo -e "   - Fast Boot: ${GREEN}Disabled${NC}"
echo -e "   - Boot Order: Set ${GREEN}nvme0n1${NC} as first boot device"
echo -e "4. Look for ${GREEN}'Kali Linux'${NC} in boot options and select it"
echo ""
echo "If GRUB still doesn't load, you may need to manually"
echo "add a boot entry in BIOS pointing to:"
echo -e "  ${CYAN}\\EFI\\kali\\grubx64.efi${NC}"
echo "  or"
echo -e "  ${CYAN}\\EFI\\Boot\\bootx64.efi${NC}"
echo ""
echo -e "${CYAN}==========================================${NC}"