how can you access an write to specific cells in array of pointers in assembly in model large?

i need to write a program in c that creates a variable long int **arr , and then allocates to each cell a partition sized m like this:

arr = malloc(n*sizeof(long int *));

for(i=0; i < n;i=i+2 )

arr[i] = malloc( m*sizeof(long int));

and then create an asm program in model large that implement the function:

extern void set_bufferred_long(long int *arr[], int buff_size, int i,long int value); -which sets cells of the array

this is my implantation of the function in asm:

.MODEL LARGE

.CODE

PUBLIC _set_bufferred_long ;set_bufferred_long(long int *arr[], int buff_size, int i,long int value)

; [bp+6] [bp+10] [bp+12] [bp+14]

_set_bufferred_long PROC far

PUSH BP ;Preserve BP register

MOV BP,SP

PUSH SI ;Preserve SI register

PUSH DI ;Preserve DI register

PUSH ES ;Preserve ES register

MOV AX,[BP+12] ;i

MOV CX,[BP+10] ;m

DIV CX ;AX=I/M DX=I%M

MOV CX,2

MOV BX,DX ;BX=I%M

MUL CX ;AX=AX*2 =(I/M)*2

MOV ES,[BP+8]

MOV DI,[BP+6] ;address of arr

ADD DI,AX ;address of a[i] is the block inside the array

MOV SI,ES:[DI] ;[di]=the address of the memory where the block starts (each block contains m long int cells)

MOV AX,BX ;AX=I%M

MOV BX,4 ;each cell is long int=4

MUL BX

ADD SI,AX

MOV AX,[BP+14] ;first part of long int

MOV ES:[SI],AX

MOV AX,[BP+16] ;second part of long int

MOV ES:[SI+2],AX

POP ES ;Restore ES register

POP DI ;Restore DI register

POP SI ;Restore SI register

POP BP ;Restore BP register

RET

_set_bufferred_long ENDP

but while the program runs and compile the values are not placed correctly in the array, when i debug i see that when i try to get the address in a[i] (with the command MOV SI,ES:[DI]) ,si only gets the offset of the array ,and not the content of the cell (which should be the address of the partition i want to write to)

what am i doing wrong? (when i do the same program in model small with the proper changes it works fine)

any help would be appreciated