Further down, under "Not everything is perfect," the author addresses the problem with /dev/urandom never blocking. Seeding /dev/urandom from /dev/random is a

Further down, under "Not everything is perfect," the author addresses the problem with /dev/urandom never blocking. Seeding /dev/urandom from /dev/random is a trick that can be used early in the boot sequence to ensure that /dev/urandom is henceforth secure. (In practice, distros carry over a seed from the previous boot which accomplishes the same effect.)