data in array (beguining boy)

[albedo]

 :wink  'ning all..

i try to put somes ddata in an array but i can't obtain at screen the value of the address an the data value  :(
i beguin with M32 and i think i've got many thing to do to be right !!!  :boohoo:

here my quote :

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««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««« *

    .486                                    ; create 32 bit code
    .model flat, stdcall                    ; 32 bit memory model
    option casemap :none                    ; case sensitive

    include \masm32\include\windows.inc     ; always first
    include \masm32\macros\macros.asm       ; MASM support macros

  ; -----------------------------------------------------------------
  ; include files that have MASM format prototypes for function calls
  ; -----------------------------------------------------------------
    include \masm32\include\masm32.inc
    include \masm32\include\gdi32.inc
    include \masm32\include\user32.inc
    include \masm32\include\kernel32.inc

  ; ------------------------------------------------
  ; Library files that have definitions for function
  ; exports and tested reliable prebuilt code.
  ; ------------------------------------------------
    includelib \masm32\lib\masm32.lib
    includelib \masm32\lib\gdi32.lib
    includelib \masm32\lib\user32.lib
    includelib \masm32\lib\kernel32.lib

   .data
      array DD ?
           

    .code                       ; Tell MASM where the code starts

; «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««

start:                          ; The CODE entry point to the program

    call main                   ; branch to the "main" procedure

    exit

; «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««

main proc

 

    push esi
    push edi

   
    mov edi,array          ; put array address into EDI

    mov esi,25h
    mov [edi],esi              ; dereference it into EDI

print str$(edi)             ; display the address of the value
    print chr$("        = address  memory",13,10)

print str$(esi)             ; display data
    print chr$("       = content ",13,10,13,10)
   
    pop edi
    pop esi

    ret

main endp

; «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««

end start                       ; Tell MASM where the program ends


5u for help...

[dedndave]

you can get rid of a lot of typing by starting with...

        INCLUDE \masm32\include\masm32rt.inc

you should take a look inside that file and see what it replaces

this code loads the dword array into EDI - not the address of it

        mov     edi,array

to get the address of array into EDI...

        mov     edi,offset array

for viewing addresses, it is handy to see them in hex form

        print   uhex$(edi),13,10

[Slugsnack]

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include \masm32\include\masm32rt.inc

.data?
   
array DD ?
           

.code
  start:

mov edi, offset array
mov esi, 25h
mov [edi], esi
    print str$(edi)             ; display the address of the value
    print chr$("        = address  memory",13,10)
    print str$(esi)             ; display data
    print chr$("       = content ",13,10,13,10)
  invoke ExitProcess, 0

end start

looks fine to me

http://img11.imageshack.us/img11/700/47129019.png

if you are just wanting to fill a single dword then you could just do :

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mov array, 25h

[BogdanOntanu]

And BTW... your "array" has space for only one single item ...
Hence as it is now it is not really an "array"... it is more like a single dword variable.

You can reserve more space for items at compile time (statically) ...  for example with:

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.data?
my_array dd 1024 dup (?)


Or you could allocate memory for your array at run time by using the API (VirtualAlloc or GlobalAlloc or HeapAlloc) and store the start of your array pointer in a variable (dynamically) with something like this:

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.data
my_array_size dd 1024*32
my_array_ptr  dd ?

.code
...
; init my_array memory buffer
invoke GlobalAlloc,[my_array_size], GPTR
mov [my_array_ptr],eax
...
; obtain a pointer to start of my_array
mov edi,[my_array_ptr]

;write first item
mov DWORD PTR [edi],25h

; next item, size of item is assumed to be 4 ... ie a DWORD ...
; but you can use STUCTURES and SIZE operator
add edi, 4

; write 2nd item
mov DWORD PTR [edi],33h
...


Do not forget to check for API failure/error in your code and use loops if you want to access a lot of array items...

[albedo]

 :dazzled: outch !!! so many good answers ! so quickly !!
and picture of dedndave ...so nice ...!  :8)
so many great things yo give me all ! very thank u to all of you... :clap:
i gona work good whit that topics...
thanks from paris my friends...4°c 9.56 pm
bye :U

[Slugsnack]

:dazzled: outch !!! so many good answers ! so quickly !!
and picture of dedndave ...so nice ...!  :8)
so many great things yo give me all ! very thank u to all of you... :clap:
i gona work good whit that topics...
thanks from paris my friends...4°c 9.56 pm
bye :U

lmao you wish that is dedndave

[dedndave]

lol - no he doesn't   :bdg

[albedo]

just one thing i try to do next,

i try to read memory by a dump
i use for it "debugx"by japheth's site , my adress to dump is at 0040300c , how can i read my contents ? d0040:300c ? d40:300c ? :red

[dedndave]

in 32-bit programs, you can directly address it

        mov     edi,40300Ch
        mov     eax,[edi]
;eax holds the dword value at address 0040300C

that may be in the code segment of the program
which, should be write-protected (as well as the const data segment)
you can read the value, but you cannot write to that address without changing permissions
if you do, it will cause the program to crash with a c0000005 access violation exception
you can change permission with the VirtualProtect API function, if you need to
if it is in the initialized or uninitialized data segment, you already have permission to write

[Slugsnack]

in 32-bit programs, you can directly address it

        mov     edi,40300Ch
        mov     eax,[edi]
;eax holds the dword value at address 0040300C

that may be in the code segment of the program
which, should be write-protected (as well as the const data segment)
you can read the value, but you cannot write to that address without changing permissions
if you do, it will cause the program to crash with a c0000005 access violation exception
you can change permission with the VirtualProtect API function, if you need to
if it is in the initialized or uninitialized data segment, you already have permission to write

or even:

Code Select Expand

mov eax, [40300Ch]

[japheth]

in 32-bit programs, you can directly address it

        mov     edi,40300Ch
        mov     eax,[edi]
;eax holds the dword value at address 0040300C

that may be in the code segment of the program
which, should be write-protected (as well as the const data segment)
you can read the value, but you cannot write to that address without changing permissions
if you do, it will cause the program to crash with a c0000005 access violation exception
you can change permission with the VirtualProtect API function, if you need to
if it is in the initialized or uninitialized data segment, you already have permission to write

or even:

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mov eax, [40300Ch]

in Masm-syntax, this just moves 40300C into EAX ... as you should know by now ... with a post count of 321. However, you can code:

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mov eax,ds:[40300Ch]

[Slugsnack]

in 32-bit programs, you can directly address it

        mov     edi,40300Ch
        mov     eax,[edi]
;eax holds the dword value at address 0040300C

that may be in the code segment of the program
which, should be write-protected (as well as the const data segment)
you can read the value, but you cannot write to that address without changing permissions
if you do, it will cause the program to crash with a c0000005 access violation exception
you can change permission with the VirtualProtect API function, if you need to
if it is in the initialized or uninitialized data segment, you already have permission to write

or even:

Code Select Expand

mov eax, [40300Ch]

in Masm-syntax, this just moves 40300C into EAX ... as you should know by now ... with a post count of 321. However, you can code:

Code Select Expand

mov eax,ds:[40300Ch]

there was no need for that condescending attitude for what was a simple mistake

[albedo]

 :U right.. it's ok , i understood...things i was looking for was a line commande under debugx like :

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-debug
-_
-
-dc800:0

C800:0000  32 E4 33 D2 B0 0A CD 17-5A C3 06 1E 60 E8 2E 01   2.3.....Z...`...
C800:0010  2E 83 0E F0 5A 00 75 6E-80 3E 00 05 01 74 67 C6   ....Z.un.>...tg.
C800:0020  06 00 05 01 8A 1E 62 04-32 FF D1 E3 8B FB 8B 85   ......b.2.......
C800:0030  50 04 8A 3E 62 04 50 32-F6 8A 0E 84 04 32 ED 41   P..>b.P2.....2.A
C800:0040  51 8B 0E 4A 04 32 D2 E8-A8 FF F6 C4 29 75 3D 51   Q..J.2......)u=Q
C800:0050  52 89 95 50 04 B4 08 E8-28 9F 0A C0 75 02 B0 20   R..P....(...u..
C800:0060  33 D2 32 E4 CD 17 F6 C4-29 75 1F 5A FE C2 59 E2   3.2.....)u.Z..Y.
C800:0070  DE FE C6 59 E2 CA E8 79-FF 32 C0 A2 00 05 58 89   ...Y...y.2....X.
-d
C800:0080  85 50 04 E8 E4 03 61 1F-07 CF 5A 59 59 B0 FF EB   .P....a...ZYY...
C800:0090  EA 52 2A F5 38 C6 7D 02-32 C0 2E 8E 06 E8 5A 5A   .R*.8.}.2.....ZZ
C800:00A0  C3 A0 85 04 F6 E3 8A F7-8B D8 8B CA BA C4 03 B8   ................
C800:00B0  02 0F EF B4 02 E8 6D 00-8B D1 32 ED 8A E6 8A C6   ......m...2.....
C800:00C0  F3 AA 03 FD 8A CA 4B 75-F7 32 E4 E8 57 00 C3 53   ......Ku.2..W..S
C800:00D0  8A 1E 62 04 0B C0 75 04-0A DB 74 03 E8 6A 03 5B   ..b...u...t..j.[
C800:00E0  8B F8 2B D1 81 C2 01 01-8A C3 32 E4 C3 8A C6 32   ..+.......2....2
C800:00F0  F6 2B EA 0A DB 74 2A 2A-C3 F6 26 85 04 8B C8 52   .+...t**..&....R



-you see ? in order to watch the adresses and find the contents...

any way i gona pass by your solutions, i think it's the best for shure... :U

[dedndave]

welllllll - debugx isn't a full-blown 32-bit debugger
if you look at it with OllyDebug, you can see 32-bit registers and addresses   :U

[albedo]

:8) niiiiiice ! i gona watch it tonight
it seems to be ok.... :clap:
thanks for all !!