🚀 go-pugleaf

I presume you are using djgpp... If not, some of my statements may be
wrong.

Brea Torremocha (cur2n9) wrote:
: I have a problem with the assembly code.
: When I try  to send a pointer as an argument of an assembler
: function, this function ignores the argument.

You have prototyped your function in a header file, haven't you ?
something like :

extern void flip(void* ptr);

: movl 8(%ebp),%esi   /* Here is the problem. The function don't take
:                        the pointer */

Are you sure about the '8' ? I often program in asm, but often
without frame pointers - I use a number of special macros I wrote for
gas that free me of the word-counting. If you want them, they are on
DJ's ftp server. Or I can mail you the latest versions.

: pushw %ds

performance remark : you'd better use "pushl %ds". I KNOW ds is only
16 bits long, but it IS a valid asm instruction (I don't know and
don't give a damn about what tha x86 does with the 16 higher
bits. Maybe it sets them to 0). That would prevent the stack pointer
from being mis-aligned - You never now when an interrupt occurs, that
will extensively use the stack, or if you call go32's services.

: If somebody knows something, please tell me.


I'd say the best thing to do is :

1st try) write your function in a separate C-file, as close as
possible to your asm-source, and compile it with -S. Take a look at
the result. You'll see if you '8' is valid or if something unexpected
happens.

2nd try) Define a string "%d\n", push your argument, call _printf
(yes, close graphics FIRST) you take a look at the value of your
argument.

By the way, be careful : some VGA don't take 32-bits acces to their
video memory. Only the 16 lower bits would be transfered.

Good luck


BTW : could you provide a valid e-mail address when you post ?
thanx...

CU

                        Igx, The dreaming drummer...

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Igx, The dreaming drummer... in real(???) life : Jean-Marc CHALLIER
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