Bootloader

This is a simple bootloader written in NASM assembly language. It is designed to be placed in the first sector of a bootable disk and executed during the boot process. The bootloader displays a welcome message, prompts the user to enter a character, and then displays the entered character on the screen.

Prerequisites

To assemble the bootloader code, you need to have NASM (Netwide Assembler) installed on your system. You can download NASM from the official website: https://www.nasm.us/

Building the Bootloader

To assemble the bootloader code, follow these steps:

1. Save the provided code in a file called bootloader.asm.

2. Open a terminal or command prompt.

3. Navigate to the directory where the bootloader.asm file is located.

4. Run the following command to assemble the code:

   nasm -f bin bootloader.asm -o bootloader.bin
   

   This command will use NASM to assemble the code into a binary file called bootloader.bin.

Running the Bootloader

Once you have the bootloader.bin file, you can run it using an emulator or write it to the first sector of a bootable disk.

Running with an Emulator

You can use an x86 emulator, such as QEMU, to run the bootloader. Follow these steps:

1. Install QEMU on your system if you haven't already. You can download QEMU from the official website: https://www.qemu.org/

2. Open a terminal or command prompt.

3. Navigate to the directory where the bootloader.bin file is located.

4. Run the following command to start the emulator and execute the bootloader:

   qemu-system-x86_64 -drive format=raw,file=bootloader.bin
   

   This command will launch the emulator and load the bootloader.bin file as the bootable disk.

Writing to a Bootable Disk

If you want to run the bootloader on real hardware, you can write the bootloader.bin file to the first sector of a bootable disk, such as a USB drive. Be cautious when performing disk operations, as it can erase or damage existing data.

Important: Writing to a disk will erase its contents. Make sure to back up any important data before proceeding.

Follow these steps to write the bootloader to a bootable disk:

1. Insert a blank bootable disk, such as a USB drive, into your computer.

2. Open a terminal or command prompt.

3. Identify the device name of the bootable disk. On Linux, you can use the lsblk command or the fdisk -l command to list available disks. On Windows, you can use the diskpart utility or third-party tools like Rufus.

4. Make sure you have the correct device name and double-check that it is the desired bootable disk.

5. Run the following command to write the bootloader to the bootable disk (replace /dev/sdx with the correct device name):

   dd if=bootloader.bin of=/dev/sdx bs=512 count=1
   

   This command will use the dd utility to write the bootloader.bin file to the first sector of the bootable disk.

   Note: Be extremely careful to specify the correct device name to avoid accidentally overwriting important data.

License

This code is provided under the MIT License. See the LICENSE file for details.