mxw
mxw

Reputation: 23

what's the meaning of %? of objdump output

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

Answers (1)

Nate Eldredge
Nate Eldredge

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

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