// BFS bootsector, first 512 bytes of a block device
export type bootsector = struct {
	// Signature of BFS, 0xCAAA
	@offset(446) signature: u16,

	// LBA of lowest yet unallocated
	// free block
	@offset(448) freeblock: u64,

	// LBA of next block in block
	// freelist
	@offset(456) nextblock: u64,
	@offset(464) lastblock: u64,

	// Inode ID of next free inode block
	@offset(472) nextinblk: u64,
	@offset(480) lastinblk: u64,

	// Inode ID of root directory
	@offset(488) rootinode: u64,

	// Log2 of size of blocks on filesystem 
	@offset(496) blocksize: u8,
};

// Fill a bootsector with everything necessary for it to be valid
export fn bootsector_make(self: *bootsector, rsvdblocks: u64) void = {
	self.signature = 0xCAAA;
	self.freeblock = rsvdblocks + 1;
	self.nextblock = 0;
	self.lastblock = 0;
	self.nextinblk = 0;
	self.lastinblk = 0;
	self.rootinode = 0;
	self.blocksize = 12;
};

// Return whether the bootsector is valid
export fn bootsector_validate(self: *bootsector) bool = {
	return self.signature == 0xCAAA;
};