mbs lecture9

7/18/2019 MBS Lecture9

1/19

!"#$%&$%#'((%$ *+(', -.(/'0(

*1123 45*6

112789

:$; 5


2/19

?


3/19

:+/+ @$+>(A'$ B>(/$C#D%>(4*+("# @.&' %A E&'$+>,(6

"##$%&'($

)*+,('+( &+($.$/ 012 342 */ 5! 6&(,7

)*+,('+( 8'9:$ &, ,(*/$% ;&($.&,($/ +:#6$/ &, $+=*%$% ;&(


4/19

:+/+ @$+>(A'$ B>(/$C#D%>(4E&'$+>, F%/+D%>(6

8-, 16-, or 32-bit memory operandmem

32-bit operand which can be a 32-bit general register or memory doublewordr/m32

16-bit operand which can be a 16-bit general-purpose register or memory wordr/m16

8-bit operand which can be an 8-bit general-purpose register or memory byter/m8

32-bit immediate doubleword valueimm3216-bit immediate word valueimm16

8-bit immediate byte valueimm8

8-, 16-, or 32-bit immediate valueimm

16-bit segment register: CS, DS, SS, ES, FS, GSsreg

Any general-purpose registerreg

32-bit general-purpose register: EAX, EBX, ECX, EDX, ESI, EDI, ESP, EBPr32

16-bit general-purpose register: AX, BX, CX, DX, SI, DI, SP, BPr16

8-bit general-purpose register: AH, AL, BH, BL, CH, CL, DH, DLr8

D$,=/&A(&*+EA$/'+%


5/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

94>$ ,41%2$ 4#$%&'( .4 ($,.3'&.34'

mov destination, source

641%2$ &'( ($,.3'&.34' 4#$%&'(, 2&' >&%+

mov reg, regmov mem, reg

mov reg, mem

mov mem, imm

mov reg, immmov r/m16, sreg

mov sreg, r/m16

?%48%&;, %1''3'8 3' #%4.$2.$( ;4($ ,@41A( '4. ;4(3/+

.@$ ,$8;$'. %$83,.$%,

B1A$,

C D4.@ 4#$%&'(, ;1,. 7$ 4/ ,&;$ ,3E$

C F4 ;$;4%+ .4 ;$;4%+ ;4>$,

C -$,.3'&.34' 2&''4. 7$ =6G H0?G 4% 0?C F4 3;;$(3&.$ .4 ,$8;$'. ;4>$,


6/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

.DATA

count BYTE 100

bVal BYTE 20

wVal WORD 2

dVal DWORD 5

.CODE

mov bl, count ; bl = count = 100

mov ax, wVal ; ax = wVal = 2

mov count,al ; count = al = 2

mov eax, dval ; eax = dval = 5

; Assembler will not accept the following moves why?

mov ds, 45

mov esi, wVal

mov eip, dVal

mov 25, bVal

mov bVal,count

; immediate move to DS not permitted

; size mismatch

; EIP cannot be the destination

; immediate value cannot be destination

; memory-to-memory move not permitted


7/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

.DATA

count BYTE 100

bVal BYTE 20

wVal WORD 2

dVal DWORD 5

.CODE






mov ds, 45

mov esi, wVal

mov eip, dVal

mov 25, bVal

mov bVal,count


; size mismatch





8/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

.DATA

count BYTE 100

bVal BYTE 20

wVal WORD 2

dVal DWORD 5

.CODE






mov ds, 45

mov esi, wVal

mov eip, dVal

mov 25, bVal

mov bVal,count


; size mismatch





9/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

.DATA

count BYTE 100

bVal BYTE 20

wVal WORD 2

dVal DWORD 5

.CODE





; Assembler will not accept the following moves why?mov ds, 45

mov esi, wVal

mov eip, dVal

mov 25, bVal

mov bVal,count


; size mismatch





10/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

.DATA

count BYTE 100

bVal BYTE 20

wVal WORD 2

dVal DWORD 5

.CODE






mov esi, wVal

mov eip, dVal

mov 25, bVal

mov bVal,count


; size mismatch





11/19

:+/+ @$+>(A'$ B>(/$C#D%>(4!EG B>(/$C#D%>6

.DATA

count BYTE 100

bVal BYTE 20

wVal WORD 2

dVal DWORD 5

.CODE






mov esi, wVal

mov eip, dVal

mov 25, bVal

mov bVal,count


; size mismatch





12/19

:+/+ @$+>(A'$ B>(/$C#D%>(4H'$% 1I/'>("%>6

J+D%> /% P'$%

JKR "( ("K>', ">/'K'$ 'SC+=( /% ';K;L 2TU V


13/19

:+/+ @$+>(A'$ B>(/$C#D%>(4H'$% 1I/'>("%>6

JKR "( ("K>', ">/'K'$ 'SC+=( /% ';K;L 2TU V

?%$$'#/ (%=CD%>O 2


14/19

:+/+ @$+>(A'$ B>(/$C#D%>(4H'$% 1I/'>("%> W !EGHX Y !EG-X6

" $ $ $ " " " "

" $ $ $ " " " "

Source

Destination$ $ $ $ $ $ $ $

$

%&'() *+,-./0-12+

3144, 567-6+8,9 -:6 /;;6. ;


15/19

:+/+ @$+>(A'$ B>(/$C#D%>(4H'$% 1I/'>("%> W !EGHX Y !EG-X6

"#$%& ()*+,-.+/0)

1/22* 345+4)6*7 +84 -994, 9:,+ 0; +84 64*+/):+/0) ,4 0; +84 *0-,.4 094,:)6?* */ : *B:22 *0-,.4 /)+0 : 2:,


16/19

:+/+ @$+>(A'$ B>(/$C#D%>(4Z5[\ Y -5[\ B>(/$C#D%>(6

Z5[\ #%&"'( /L

H'$%L 5CI"="+$. ?+$$.L _+$"/. +>, ?+$$.;

-5[\ ,%( /


17/19

:+/+ @$+>(A'$ B>(/$C#D%>(4X?[^ B>(/$C#D%>(6

&EFG 45.8:)


18/19

:+/+ @$+>(A'$ B>(/$C#D%>(4:"$'#/ !'0%$. E&'$+>,(6

"#$%#&'( *#+(, #$( $(-($(*.(, /0 '0.#/%0*, %* +(+0$1

2%$(./ 3(+0$1 45($#*67

8#+(6 $(-($(*.( /0 # +(+0$1 '0.#/%0*

9,,(+&'($ .0+5:/(, #66$(,, ;0--,(/< 0- *#+(6 =#$%#&'(

.DATA

var1 BYTE 10h

.CODE

mov al, var1 ; AL = var1 = 10h

mov al,[var1] ; AL = var1 = 10h

Direct Memory Operand

Alternate Format


19/19

:+/+ @$+>(A'$ B>(/$C#D%>(4:"$'#/ !'0%$. E&'$+>,(6

.DATA

arrayB BYTE 10h,20h,30h,40h

.CODE

mov al, arrayB+1 ; AL = 20hmov al,[arrayB+1] ; alternative notation

mov al, arrayB[1] ; yet another notation

2%$(./C4--,(/ 45($#*67 D0*,/#*/ 0--,(/ %, #66(6 /0 #

*#+(6 +(+0$1 '0.#/%0* /0 5$06:.( #* (--(./%=( #66$(,,

9,,(+&'($ .0+5:/(, /@( (--(./%=( #66$(,,

E(/, 10: #..(,, +(+0$1 '0.#/%0*, /@#/ @#=( *0 *#+(

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