auracaster-os/flash_sdcard.sh

#!/bin/bash
#
# Script to flash the Auracaster System image to an SD card
# This script must be run with sudo privileges

set -e

# Configuration
BUILDROOT_DIR="../buildroot"
IMAGE_FILE="$BUILDROOT_DIR/output/images/sdcard.img"
AUTO_YES=false

# Parse command line arguments
while getopts "y" opt; do
  case $opt in
    y)
      AUTO_YES=true
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      exit 1
      ;;
  esac
done

# Check if script is run as root
if [ "$(id -u)" -ne 0 ]; then
    echo "Error: This script must be run as root (sudo)."
    exit 1
fi

# Check if image exists
if [ ! -f "$IMAGE_FILE" ]; then
    echo "Error: Image file not found at $IMAGE_FILE"
    echo "You need to build the project first."
    exit 1
fi

# Find SD cards (both removable devices and mmcblk devices)
echo "Looking for SD cards..."
echo

# Get list of potential SD cards (both removable devices and mmcblk devices)
SD_CARDS=$(lsblk -d -o NAME,SIZE,MODEL,VENDOR,TRAN,RM | grep -v "loop" | grep -E '(1$|mmcblk)' | awk '{print $1}')
SD_CARD_COUNT=$(echo "$SD_CARDS" | grep -v "^$" | wc -l)

if [ "$SD_CARD_COUNT" -eq 0 ]; then
    echo "No SD cards found. Please insert an SD card and try again."
    exit 1
fi

# Display available SD cards
echo "Available SD cards:"
echo
lsblk -d -o NAME,SIZE,MODEL,VENDOR,TRAN,RM | head -n 1
lsblk -d -o NAME,SIZE,MODEL,VENDOR,TRAN,RM | grep -v "loop" | grep -E '(1$|mmcblk)'
echo

# Safety check - get list of internal disks to avoid (exclude mmcblk devices from this check)
INTERNAL_DISKS=$(lsblk -d -o NAME,RM | grep -E '0$' | grep -v "mmcblk" | awk '{print $1}')

# Select SD card
DEVICE=""
if [ "$SD_CARD_COUNT" -eq 1 ]; then
    DEVICE=$(echo "$SD_CARDS" | tr -d '[:space:]')
    echo "Found single SD card: /dev/$DEVICE"
else
    echo "Multiple SD cards found. Please select which one to use:"
    select DEVICE in $SD_CARDS; do
        if [ -n "$DEVICE" ]; then
            break
        else
            echo "Invalid selection. Please try again."
        fi
    done
fi

# Safety check - ensure we're not flashing to an internal disk
if echo "$INTERNAL_DISKS" | grep -q "$DEVICE"; then
    echo "ERROR: Selected device /dev/$DEVICE appears to be an internal disk!"
    echo "This script will only flash to removable devices or mmcblk devices for safety."
    exit 1
fi

# Validate device exists
if [[ "$DEVICE" == mmcblk* ]]; then
    DEV_PATH="/dev/$DEVICE"
else
    DEV_PATH="/dev/$DEVICE"
fi

if [ ! -b "$DEV_PATH" ]; then
    echo "Error: Device $DEV_PATH does not exist or is not a block device."
    exit 1
fi

# Double-check with clear warning
echo
echo "You are about to erase ALL DATA on $DEV_PATH and write the Auracaster System image to it."
echo "This operation cannot be undone."
echo

# Check if pv is available for better progress display
if command -v pv >/dev/null 2>&1; then
    # Get image size for pv
    IMAGE_SIZE=$(stat -c %s "$IMAGE_FILE")
    
    # Show the command that will be executed with pv
    FLASH_COMMAND="pv -s $IMAGE_SIZE \"$IMAGE_FILE\" | dd of=\"$DEV_PATH\" bs=4M conv=fsync oflag=direct"
    echo "The following command will be executed (with progress bar):"
    echo "$FLASH_COMMAND"
else
    # Fallback to dd with status=progress
    FLASH_COMMAND="dd if=\"$IMAGE_FILE\" of=\"$DEV_PATH\" bs=4M status=progress conv=fsync oflag=direct"
    echo "The following command will be executed:"
    echo "$FLASH_COMMAND"
    echo "For better progress visualization, consider installing 'pv' (Pipe Viewer)."
fi
echo

if [ "$AUTO_YES" = true ]; then
    CONFIRM="y"
    echo "Auto-confirming with -y flag"
else
    read -p "Are you ABSOLUTELY SURE you want to continue? (y/n): " CONFIRM
    
    if [ "$CONFIRM" != "y" ]; then
        echo "Operation cancelled."
        exit 0
    fi
fi

# Unmount any partitions on the device
echo "Unmounting any mounted partitions on $DEV_PATH..."
if [[ "$DEVICE" == mmcblk* ]]; then
    for partition in $(lsblk -n -o NAME | grep "^$DEVICE"); do
        if [ "$partition" != "$DEVICE" ]; then
            umount "/dev/$partition" 2>/dev/null || true
        fi
    done
else
    for partition in $(lsblk -n -o NAME /dev/$DEVICE | grep -v "^$DEVICE$"); do
        umount "/dev/$partition" 2>/dev/null || true
    done
fi

# Flash the image
echo "Flashing image to $DEV_PATH..."
echo "This may take several minutes. Please wait..."
echo

# Execute the flashing command
eval "$FLASH_COMMAND"

# Sync to ensure all writes are complete
sync

echo
echo "Flash complete!"
echo

# Remind user to eject the card safely
echo "You can now safely remove the SD card."
echo "1. Insert the SD card into your Raspberry Pi 3"
echo "2. Power on the device"
echo "3. Access the SWUpdate web interface at http://<raspberry-pi-ip>:8080"
echo

exit 0