More work on writing

writer_write.go

@@ -3,10 +3,26 @@ package squashfs
 import (
 	"errors"
 	"io"
+	"math"
 )
 
 //WriteTo attempts to write the archive to the given io.Writer.
 func (w *Writer) WriteTo(write io.Writer) (int64, error) {
-	//TODO
+	if w.BlockSize > 1048576 {
+		w.BlockSize = 1048576
+	} else if w.BlockSize < 4096 {
+		w.BlockSize = 4096
+	}
+	//TODO: set forced Flag values
+	_ = superblock{
+		Magic:           magic,
+		BlockSize:       w.BlockSize,
+		BlockLog:        uint16(math.Log2(float64(w.BlockSize))),
+		CompressionType: uint16(w.compressionType),
+		Flags:           w.Flags.ToUint(),
+		IDCount:         uint16(len(w.uidGUIDTable)),
+		MajorVersion:    4,
+		MinorVersion:    0,
+	}
 	return 0, errors.New("I SAID DON'T")
 }