Don&#x27;t forget the Segfault bug on the Intel Quark (which doesn&#x27;t have killbits - oops) [1], or the stack pointer overflow bug that Matt Dillon found compiling DragonflyBSD [2], or the Barcelona &quot;you weren&#x27;t really using your TLB, were you?&quot; cache coherency bug [3].<p>Microcode is also in multiple places - there&#x27;s a flavor baked into your chip, flavors baked into your BIOS to boot on your CPU if its rev is lower, and flavors pushed into {Windows,Linux,...} that also flash if their revs are newer.<p>[1] - <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Intel_Quark#Segfault_bug" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Intel_Quark#Segfault_bug</a><p>[2] - <a href="http:&#x2F;&#x2F;wiki.osdev.org&#x2F;CPU_Bugs#DragonFly_BSD_Heavy_Load_Crash" rel="nofollow">http:&#x2F;&#x2F;wiki.osdev.org&#x2F;CPU_Bugs#DragonFly_BSD_Heavy_Load_Cras...</a><p>[3] - <a href="http:&#x2F;&#x2F;www.anandtech.com&#x2F;show&#x2F;2477&#x2F;2" rel="nofollow">http:&#x2F;&#x2F;www.anandtech.com&#x2F;show&#x2F;2477&#x2F;2</a>