Reputation: 23
what's meaning of %? at 402cce? Is this a invalid instruction?
402cca: 80 c6 28 add $0x28,%dh
402ccd: 9d popf
402cce: 8e 3e mov (%esi),%?
402cd0: 23 7b 05 and 0x5(%ebx),%edi
402cd3: fc cld
402cd4: b2 de mov $0xde,%dl
Upvotes: 2
Views: 163
Reputation: 58142
Yes, it's invalid. Opcode 8e
is mov sreg, r/m
, the instruction to load a segment register, where the desired segment register is to be encoded in the 3-bit reg
field of the ModRM byte (bits 3-5). But there are only 6 segment registers, so having 110
or 111
in this field is undefined.
Upvotes: 1