The script will automatically detect the USB device and prompt the user for any necessary information.
The script automatically detects the USB device.
It prompts the user for the root device and video mode, with a default value for the video mode if none is provided.
It mounts the USB device, loads the kernel and initrd using kexec, and executes the loaded kernel.
Finally, it disables any swap space to prevent conflicts.

#!/bin/bash

# Function to detect the USB device
detect_usb_device() {
    echo "Detecting USB device..."
    USB_DEVICE=$(lsblk -o NAME,MOUNTPOINT | grep -E "sd[b-z]1\s*$" | awk '{print $1}')
    if [ -z "$USB_DEVICE" ]; then
        echo "Error: No USB device detected."
        exit 1
    fi
    echo "USB device detected: /dev/$USB_DEVICE"
    USB_DEVICE="/dev/$USB_DEVICE"
}

# Function to mount the USB device
mount_usb_device() {
    echo "Mounting USB device to $USB_MOUNT_POINT..."
    mount $USB_DEVICE $USB_MOUNT_POINT
    if [ $? -ne 0 ]; then
        echo "Error: Failed to mount USB device."
        exit 1
    fi
    echo "USB device mounted successfully."
}

# Function to get user input for the root device and video mode
get_user_input() {
    read -p "Enter the root device (e.g., /dev/ps3da1): " ROOT_DEVICE
    read -p "Enter the video mode (default is 720p): " VIDEO_MODE
    VIDEO_MODE=${VIDEO_MODE:-720p}
}

# Set variables for USB mount point and kernel/initrd paths
USB_MOUNT_POINT="/mnt/usb"

# Detect the USB device
detect_usb_device

# Check if USB device is already mounted
if ! mount | grep -q "$USB_MOUNT_POINT"; then
    mount_usb_device
else
    echo "USB device already mounted."
fi

# Get user input for root device and video mode
get_user_input

# Set kernel and initrd paths
KERNEL_PATH="$USB_MOUNT_POINT/vmlinux"
INITRD_PATH="$USB_MOUNT_POINT/initrd.gz"

# Load the kernel and initrd using kexec
echo "Loading kernel and initrd..."
kexec -l $KERNEL_PATH --initrd=$INITRD_PATH --append="root=$ROOT_DEVICE video=$VIDEO_MODE"
if [ $? -ne 0 ]; then
    echo "Error: Failed to load kernel and initrd."
    exit 1
fi

# Synchronize filesystem changes
echo "Synchronizing filesystem changes..."
sync

# Execute the loaded kernel
echo "Executing the loaded kernel..."
kexec -e
if [ $? -ne 0 ]; then
    echo "Error: Failed to execute the loaded kernel."
    exit 1
fi

# Disable swap (if any)
echo "Disabling swap..."
swapoff -a
if [ $? -ne 0 ]; then
    echo "Error: Failed to disable swap."
    exit 1
fi

echo "Boot process complete."




How it works:
The script detects and mounts the USB device.
It prompts the user for the root device and video mode.
It displays a menu of available firmware files on the USB device and allows the user to select one.
It flashes the selected firmware file to the HDD (you need to specify the appropriate flashing command and target HDD device).
It loads the kernel and initrd using kexec and boots into the new environment.
It disables any swap space to prevent conflicts.


#!/bin/bash

# Function to detect the USB device
detect_usb_device() {
    echo "Detecting USB device..."
    USB_DEVICE=$(lsblk -o NAME,MOUNTPOINT | grep -E "sd[b-z]1\s*$" | awk '{print $1}')
    if [ -z "$USB_DEVICE" ]; then
        echo "Error: No USB device detected."
        exit 1
    fi
    echo "USB device detected: /dev/$USB_DEVICE"
    USB_DEVICE="/dev/$USB_DEVICE"
}

# Function to mount the USB device
mount_usb_device() {
    echo "Mounting USB device to $USB_MOUNT_POINT..."
    mount $USB_DEVICE $USB_MOUNT_POINT
    if [ $? -ne 0 ]; then
        echo "Error: Failed to mount USB device."
        exit 1
    fi
    echo "USB device mounted successfully."
}

# Function to get user input for the root device and video mode
get_user_input() {
    read -p "Enter the root device (e.g., /dev/ps3da1): " ROOT_DEVICE
    read -p "Enter the video mode (default is 720p): " VIDEO_MODE
    VIDEO_MODE=${VIDEO_MODE:-720p}
}

# Function to display a menu and let the user select the firmware file
select_firmware_file() {
    echo "Available firmware files:"
    PS3='Please select the firmware file to flash: '
    options=($(ls $USB_MOUNT_POINT/*.bin))
    select opt in "${options[@]}"; do
        if [[ -n "$opt" ]]; then
            FIRMWARE_FILE="$opt"
            break
        else
            echo "Invalid option. Try again."
        fi
    done
    echo "Selected firmware file: $FIRMWARE_FILE"
}

# Function to flash the firmware to the HDD
flash_firmware() {
    echo "Flashing firmware to HDD..."
    # Add your firmware flashing command here. For example:
    # dd if=$FIRMWARE_FILE of=/dev/ps3da bs=4096
    # Note: Replace /dev/ps3da with the actual HDD device
    if [ $? -ne 0 ]; then
        echo "Error: Failed to flash firmware."
        exit 1
    fi
    echo "Firmware flashed successfully."
}

# Set variables for USB mount point
USB_MOUNT_POINT="/mnt/usb"

# Detect the USB device
detect_usb_device

# Check if USB device is already mounted
if ! mount | grep -q "$USB_MOUNT_POINT"; then
    mount_usb_device
else
    echo "USB device already mounted."
fi

# Get user input for root device and video mode
get_user_input

# Display the menu to select the firmware file
select_firmware_file

# Flash the selected firmware file to the HDD
flash_firmware

# Load the kernel and initrd using kexec
echo "Loading kernel and initrd..."
kexec -l $KERNEL_PATH --initrd=$INITRD_PATH --append="root=$ROOT_DEVICE video=$VIDEO_MODE"
if [ $? -ne 0 ]; then
    echo "Error: Failed to load kernel and initrd."
    exit 1
fi

# Synchronize filesystem changes
echo "Synchronizing filesystem changes..."
sync

# Execute the loaded kernel
echo "Executing the loaded kernel..."
kexec -e
if [ $? -ne 0 ]; then
    echo "Error: Failed to execute the loaded kernel."
    exit 1
fi

# Disable swap (if any)
echo "Disabling swap..."
swapoff -a
if [ $? -ne 0 ]; then
    echo "Error: Failed to disable swap."
    exit 1
fi

echo "Boot process complete."