broken go-disks fat32 example

fat32.go

package main

import (
	"fmt"
	"io"
	"os"

	"github.com/diskfs/go-diskfs/filesystem/fat32"
)

func main() {
	var size int64 = 128 * 1024 * 1024
	fp, err := os.OpenFile("/tmp/fat", os.O_TRUNC|os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644)
	if err != nil {
		fmt.Printf("open failed: %v", err)
		os.Exit(1)
	}
	_, err = fat32.Create(fp, size, 0, 512, "EFIBOOT")
	if err != nil {
		fmt.Printf("Create failed: %v", err)
		os.Exit(1)
	}
	defer fp.Close()
	fs, err := fat32.Read(fp, size, 0, 512)
	if err != nil {
		fmt.Printf("fat32.Read failed: %v", err)
		os.Exit(1)
	}
	src, err := os.Open("/tmp/in")
	if err != nil {
		fmt.Printf("os.Open failed: %v", err)
		os.Exit(1)
	}
	defer src.Close()
	err = fs.Mkdir("/EFI/BOOT")
	if err != nil {
		fmt.Printf("mkdir failed: %v", err)
		os.Exit(1)
	}
	dest, err := fs.OpenFile("/EFI/BOOT/kernel.efi", os.O_CREATE|os.O_RDWR|os.O_TRUNC)
	if err != nil {
		fmt.Printf("fs.OpenFile failed: %v", err)
		os.Exit(1)
	}
	defer dest.Close()
	b, err := io.Copy(dest, src)
	if err != nil {
		fmt.Printf("io.Copy failed: %v", err)
		os.Exit(1)
	}
	fmt.Printf("copied %d bytes\n", b)
}