Set DE_CFG[9] -- a chickenbit which stops Zenbleed. The chickenbit may
have other side-effects (not disclosed by AMD), and firmwares fixes may
be better (and have other side-effects, same story). Newer processors
will probably be validated more carefully by AMD.
Issue found by Tavis Ormandy.
This is errata 7.2/033_amdcpu.patch.sig and 7.3/011_amdcpu.patch.sig
Zenbleed also blocked on select cpus by using errata
7.3/012_amdfirmware.patch.sig + 7.3/013_amdcpufirmware.patch /
7.2/034_amdfirmware.patch.sig + 7.2/035_amdcpufirmware.patch.sig
which load AMD cpu firmwares (firmware.openbsd.org is updated often to
contain the best firmwares)
ok jsg