Date: Mon, 27 Apr 1998 15:25:08 +0200 (CEST)
From: Archee/CoNTRACT <01dsolt AT Vpg17 DOT vpg DOT hu>
To: Aurelio <erigotti AT tinet DOT ch>
cc: djgpp AT delorie DOT com
Subject: Re: A strange memory problem
In-Reply-To: <01bd7094$1de72440$78001dc2@rigotti>
Message-ID: <Pine.LNX.3.96.980427151631.505C-100000@Vpg17.vpg.hu>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk

hi !

It is not strange.
You have to put $16000 in %ecx, not %cx.
you have to save %es by pushing it.

I do it in the following way:

short screenselector;  <- have to be GLOBAL (ds)

void proc {
screenselector=__dpmi_createselector(1); // I cannot remember exactly of
the procedures name.

__dpmi_set_selector_base(screenselector,0xa0000);
__dpmi_set_selector_limit(screenselector,320*200);

__asm__ ("
 pushw %es
 movw _screenselector,%es
 cld
 xorl %edi,%edi
 movl _framebuffer,%esi
 movl $16000,%ecx
 rep 
  MOVSL  /* MOVSL uses ES for DEST and DS for src */
 popw %es
 ");

My way works under win95 and DOS fine. 

BUT the bigger problame:
 You can use 16bit and 32 bit/pixel using VBE 1.2 or VBE 2.0

I think you have to write it for VBE 1.2 and VBE 2.0 to.
I have an engine for that. (supporting VBE 2.0 and 1.2 too, and convert
the picture to 16bit/pixel if the user dont have 32 bit/pixel.....)
I can send it to ya. Just mail me at soltesz AT hotmail DOT com

-- Archee/CoNTRACT  CODER   ( 01dsolt AT vpg DOT hu  )
oldnikk:stonee,sutyi
web: http://gondolat.vpg.hu/~01dsolt

On 25 Apr 1998, Aurelio wrote:

> I have a very strange problem with DJGPP. I'm using DJGPP under WIN95 
> with the gcc compiler. I wrote this code:
> 
> int main()
> {
>   Set_Video_Mode(0x13);
> 
>   BYTE * DoubleBuffer = (BYTE *) calloc(64000,1);
> 
>   BYTE * test = (BYTE *)malloc(10);
>   free(test);
> 
>   //copy of DoubleBuffer in video memory
>   __asm__ __volatile__("       \n
>   cld                          \n
>   movw $16000,%%cx             \n
>   movw %1,%%es                 \n
>   movl $0xA0000,%%edi          \n
>   movl %0,%%esi                \n
>   rep                          \n
>   movsl                         "
>   :
>   :"S"(DoubleBuffer),"g"(_dos_ds)
>   :"edi","cx","ebx","memory"
>   );
> 
>   free(DoubleBuffer);
> 
>   return 0;
> }
> 
> When I execute this code the program crashes with the error:
>        General protection fault etc..
> 
> If I delete the 2 lines that allocate the 10 bytes 
>   BYTE * test = (BYTE *)malloc(10);
>   free(test);
> 
> the program doesn't crash.
> 
> Someone can help? 
> 
>