Super-secret' debugger discovered in AMD CPUs
A hardware hacker has discovered a secret debugging feature hidden in all AMD chips made in the past decade.
The password-protected debugger came as a shock to reverse-engineers who have hungered for an on-chip mechanism for performing conditional and direct-hardware breakpoint operations. Although AMD has built the firmware-controlled feature into all chips since the Athlon XP, the company kept it a closely guarded secret that was only disclosed late last week by a hacker who goes by the name Czernobyl.
You don't need to be a genius to debug a pf.conf firewall ruleset, you just need the guts to run tcpdump