Simple bootloader. Main purpose are floppy disks.

Contains read-only FAT12 driver, but there are few bad things:

• Size of BPB and FAT tables (combined) should not be more than 27KB, because BPB and FAT table is loaded to 0x0:0x1000.
• Do not load anything to an address lower than 0x20000 + size of configuration file. It is reserved area for bootloader.
• For now does not support partitions.

1. Install NASM and run make.
2. Write bootsector to the FAT12 formatted (floppy) disk. You can use dd:

dd if=vbr/vbr.bin of=/dev/fd0 skip=62c seek=62c bs=1c count=450 conv=notrunc

3. Put bootloader/boot.bin and kernel into the root directory.
4. Create btconfig.cfg file there and write configuration. Here are commands used to generate proper configuration file:

# Placing destination address needs to be done in little endian. For example 0x00030000 will be 0x00, 0x00, 0x00, 0x30 and combined "\x00\x00\x00\0x30".
printf "F<FAT12 filename><address in format described above>\x0a" >> btconfig.cfg
# If you need, you can of course load more files than 1. Use the same method.
printf "J<11 spaces><address in the same format>\x0a" >> btconfig.cfg
printf "\x00" >> btconfig.cfg

If you want to use this FAT12 driver in your second stage bootloader or bootsector, read license, take shared/fat.asm and go working, but do not forget; you should add some honorable mentions.

If you want to know how data is stored on FAT12 filesystem, check parsefat.c. It is a simple C program which reads FAT12 disk image, searches for specified file and displays content of each cluster assigned to this file.

Bootloader is licensed under BSD3 license.