I created many assembly programs with nasm and I always tested them with qemu (system-x86_64). I would like to create a bootable disk image that I can burn on an USB stick and plug it in my second computer for testing.
For qemu I just needed to make the file end with 0x55aa and make it long 512 bytes.
However I can't seem to find a way to convert my file to a bootable format.
I know that it's better to create a virtual machine using VirtualBox or other software and do my tests in a protected environment to avoid accidental overwriting of files on my SSD drive, but I still face the same problem: VBox only accepts ISO/IMG files (hard drive and floppy).