diff --git a/writeup/3.md b/writeup/3.md
index 7d2d9db..2297bdc 100644
--- a/writeup/3.md
+++ b/writeup/3.md
@@ -14,3 +14,28 @@ Below that, we have a struct called `ext2fs_vfsops` which just contains values t
 
 At this point, we should see where in the mounting process ext4 fails. Create an ext4 filesystem using qemu and mount it; make sure that the virtual machine manager marks it as a readonly filesystem before mounting it to ensure that it doesn't get corrupted (at least, not yet).
 
+Finally, on line 106 we have the `ext2fs_mountroot` function. This is where the bulk of our analysis will start.
+
+```c
+	struct m_ext2fs *fs;
+    struct mount *mp;
+	struct proc *p = curproc;	/* XXX */
+	struct ufsmount *ump;
+	int error;
+
+	/*
+	 * Get vnodes for swapdev and rootdev.
+	 */
+	if (bdevvp(swapdev, &swapdev_vp) || bdevvp(rootdev, &rootvp))
+		panic("ext2fs_mountroot: can't setup bdevvp's");
+```
+
+So here we have to figure out what exactly the bdevvp function is. 
+From the OpenBSD man page:
+> bdevvp() will create a vnode for a block device, and is used for the root device and swap areas, among other things.
+
+I guess our question starts at, what exactly is a virtual node? It's nothing more than "an abstract ayer on top of a more concrete filesystem." (Wikipedia). 
+
+Meaning nothing more than what we have to do in order for there to be no difference when we run `ls`, `cd`, `rm`, `mkdir`, etc. Abstractions are necessary.
+
+