FBoot

Extraordinarily simple real mode bootloader written in NASM for x86 BIOS.

FBoot sets up a basic and safe environment, loads the specified sector amount, and jumps to the raw loaded segment.

I do not suggest using FBoot for any serious production projects, this is primarily educational.

Usage

• Building on a UNIX-like operating system like Linux is strongly recommended.
• Ensure you have Git, GNU Make, and Nasm installed on your system.
• Clone the repository: git clone https://github.com/FeltMacaroon389/FBoot.git
• Move into the cloned directory: cd FBoot
• Run make to build the output image. By default, this will be located in bin/fboot.bin
• To use with your kernel, ensure it is assembled as a raw binary. Then, concatenate your FBoot binary with your kernel, placing FBoot first.
• For example, if your FBoot binary is named fboot.bin and your kernel source file is named kernel.asm and written with NASM syntax:
  • nasm -f bin -o kernel.bin kernel.asm
  • cat fboot.bin kernel.bin > boot.img
• This will produce a bootable image at boot.img
• If you wish for your kernel to return, it's important to use the retf instruction instead of normal ret

Supported languages

Currently, only binaries assembled directly from assembly language is supported. However, higher-level languages like C may work, provided it's compiled to a raw binary and that there are no additional files or headers included above the entrypoint.

License

FBoot is licensed under the GNU GPLv3 license. For more information, see the LICENSE file in the root directory.