Ok. I need to know when a program reachs certain location in its code.
I dont have the source of it, so my idea:
This is a piece of the code. I need to know when the program reachs
address 071a:0d3c.
I wrote a tsr with a int60h handler, and change address 071a:0d3c to
call int 60h. (cd 60).
071A:00000D37 50 PUSH AX
071A:00000D38 51 PUSH CX
071A:00000D39 52 PUSH DX
071A:00000D3A 56 PUSH SI
071A:00000D3B 57 PUSH DI
071A:00000D3C 33 DB XOR BX,BX (Change this
to CD 60) <<<<<<<<<<<<<<
071A:00000D3E B9 F0 03 MOV CX,03F0
071A:00000D41 BA 83 07 MOV DX,0783
071A:00000D44 B3 03 MOV BL,03
071A:00000D46 E8 E7 00 CALL (+00E7)
071A:00000D49 8A 1C MOV BL,[SI]
071A:00000D4B E8 E2 00 CALL (+00E2)
071A:00000D4E 02 FB ADD BH,BL
071A:00000D50 46 INC SI
071A:00000D51 E2 EE LOOP (-12)
071A:00000D53 5F POP DI
071A:00000D54 5E POP SI
071A:00000D55 5A POP DX
071A:00000D56 59 POP CX
071A:00000D57 58 POP AX
071A:00000D58 C3 RET
Good, now i can do anything when the program gets there. Then, at the
end of my int, i do the xor bx,bx and push it to the stack, so the
program can continue with its bx =3D 0. Int handler is written in c++,
doing those regular pushes and pops.
void interrupt int61(void)
{
a++;
asm pop bx;
asm xor bx,bx;
asm push bx;
}
Not working. I disassembled my int handler and it looks fine, the
assembly flow is ok.
My question is what could go wrong here? Could my int be changing flags
or any other things? Also, could I use dos ints from my int in that
case? (Like fopen, fwrite...) I know this procedure isn=B4t called from
any other int.
Sorry, may look a little confusing.
Tks,
Pedro.
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