[syslinux] Confusion regarding cpu-arch values for EFI ByteCode and 64-bit

Phil Pokorny ppokorny at penguincomputing.com
Thu Apr 21 21:13:43 PDT 2016

This document:

Has the same (plus expanded) list of cpu arch values for parameter 0x93.
This list matches RFC 4578 except for values 7 and 9 which are EFI ByteCode
and x86-64.

Turns out RFC 4578 is wrong


And 00:07 *is* the correct value for 64-bit x86 clients and the comment on
the wiki should be updated.  See:


That said, because RFC 4578 is still shown incorrectly unless you click on
the "ERRATA" we will probably see clients written with the "wrong" values
for quite some time and we should probably continue to recommend that both
7 and 9 be accepted as efi 64-bit and assume that no one would ever
knowingly use ByteCode...

Just FYI,
Phil P.

Philip Pokorny, RHCE
Chief Technology Officer

Changing the world through technical innovation

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