MOV
From Asmpedia
Move (general purpose)
| Intel | AMD |
|---|---|
| + | + |
Definition:
MOV DST, SRC
Replaces the value (contents) of the first operand (DST) with the value (contents) of the second operand (SRC) or, in another words, copies the contents of the second operand (SRC) to the first operand (DST)
Operation in pseudo code:
mov(r/mem/seg dst, imm/r/mem/seg src)
{
#if sizeof(dst) != sizeof(src)
#error both operands must have the same size (8/16/32/64)
#endif
#if dst is mem && src is mem
#error both operands cannot be memory addresses
#endif
#if dst is imm
#error destination cannot be a constant
#endif
#if dst is seg && src is seg
#error both operands cannot be segment registers
#endif
if (dst == CS)
{
throw #UD; // invalid opcode exception
}
if (dst is seg)
{
validate_segment(src);
}
if (dst == SS)
{
// disable all interrupts until the end of the next instruction execution (loading ESP)
}
dst = src;
}
Opcodes (x86):
| 88 | mod (xx) reg (xxx) r/m (xxx) | MOV r/mem8, r8 | - |
| 89 | mod (xx) reg (xxx) r/m (xxx) | MOV r/mem16/32, r16/32 | - |
| 8a | mod (xx) reg (xxx) r/m (xxx) | MOV r8, r/mem8 | - |
| 8b | mod (xx) reg (xxx) r/m (xxx) | MOV r16/32, r/mem16/32 | - |
| 8c | mod (xx) reg (xxx) r/m (xxx) | MOV r/mem16, seg | - |
| 8e | mod (xx) reg (xxx) r/m (xxx) | MOV seg, r/mem16 | - |
| a0 | - | MOV AL, offset8 | AL := byte ptr seg:[offset8] |
| a1 | - | MOV (E)AX, offset16/32 | (E)AX := (d)word ptr seg:[offset16/32] |
| a2 | - | MOV offset8, AL | byte ptr seg:[offset8] := AL |
| a3 | - | MOV offset16/32, (E)AX | (d)word ptr seg:[offset16/32] := (E)AX |
| b0 | - | MOV AL, imm8 | - |
| b1 | - | MOV СL, imm8 | - |
| b2 | - | MOV DL, imm8 | - |
| b3 | - | MOV BL, imm8 | - |
| b4 | - | MOV AH, imm8 | - |
| b5 | - | MOV CH, imm8 | - |
| b6 | - | MOV DH, imm8 | - |
| b7 | - | MOV BH, imm8 | - |
| b8 | - | MOV (E)AX, imm16/32 | - |
| b9 | - | MOV (E)CX, imm16/32 | - |
| ba | - | MOV (E)DX, imm16/32 | - |
| bb | - | MOV (E)BX, imm16/32 | - |
| bc | - | MOV (E)SP, imm16/32 | - |
| bd | - | MOV (E)BP, imm16/32 | - |
| be | - | MOV (E)SI, imm16/32 | - |
| bf | - | MOV (E)DI, imm16/32 | - |
| с6 | mod (xx) reg (000) r/m (xxx), imm8 | MOV r/mem8, imm8 | - |
| с7 | mod (xx) reg (000) r/m (xxx), imm16/32 | MOV r/mem16/32, imm16/32 | - |
EFLAGS
:31 | :30 | :29 | :28 | :27 | :26 | :25 | :24 | :23 | :22 | ID :21 | VIP :20 | VIF :19 | AC :18 | VM :17 | RF :16 | :15 | NT :14 | IOPL :13:12 | OF :11 | DF :10 | IF :9 | TF :8 | SF :7 | ZF :6 | :5 | AF :4 | :3 | PF :2 | :1 | CF :0 |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | - | - | - | - | - | - | 0 | - | - | - | - | - | - | - | - | 0 | - | 0 | - | 1 | - |
Annotated WinDbg disassembly (x86):
8bff mov edi,edi ; 8b: opcode ff: mod=11 reg=111 EDI r/m=111 EDI 8bec mov ebp,esp ; 8b: opcode ec: mod=11 reg=101 EBP r/m=100 ESP 8bf8 mov edi,eax 8945fc mov dword ptr [ebp-4],eax 8975e8 mov dword ptr [ebp-18h],esi b80b800000 mov eax,800Bh 8b3da8120001 mov edi,dword ptr [010012a8] 8bd8 mov ebx,eax a13c980001 mov eax,dword ptr [0100983c] 8b45e8 mov eax,dword ptr [ebp-18h] 8b483c mov ecx,dword ptr [eax+3Ch] 8a06 mov al,byte ptr [esi] 8bf0 mov esi,eax 8bc6 mov eax,esi c745fc01000000 mov dword ptr [ebp-4],1 ; c7: opcode 45: mod=01 reg=000 r/m=101 [EBP+disp8] fc: -4 01000000: 1 (imm32)
Annotated WinDbg disassembly (x64):
48899d28050000 mov qword ptr [rbp+528h],rbx 4889b530050000 mov qword ptr [rbp+530h],rsi 4889bd38050000 mov qword ptr [rbp+538h],rdi 4c89a508050000 mov qword ptr [rbp+508h],r12 488b05b7b50200 mov rax,qword ptr [00000000`78c11108] 488985f0040000 mov qword ptr [rbp+4F0h],rax 65488b042530000000 mov rax,qword ptr gs:[30h] 488bf1 mov rsi,rcx 488988d0140000 mov qword ptr [rax+14D0h],rcx 65488b042530000000 mov rax,qword ptr gs:[30h] 48898808150000 mov qword ptr [rax+1508h],rcx 8bf8 mov edi,eax 448bc7 mov r8d,edi 48c7c1ffffffff mov rcx,0FFFFFFFFFFFFFFFFh 488b8df0040000 mov rcx,qword ptr [rbp+4F0h] 488b9d28050000 mov rbx,qword ptr [rbp+528h] 488bb530050000 mov rsi,qword ptr [rbp+530h] 488bbd38050000 mov rdi,qword ptr [rbp+538h] 4c8ba508050000 mov r12,qword ptr [rbp+508h]
