From: "Kecskemeti Balazs" <balazs AT tiszanet DOT hu>
Newsgroups: comp.os.msdos.djgpp
Subject: _farsetsel?
Date: Wed, 31 Mar 1999 15:40:03 +0200
Organization: MatavNet
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

Hi!

i compiled something like this:

#include "vesa.h"
#include <dpmi.h>
#include <sys\farptr.h>
#include <stdio.h>

int main()
{
    __dpmi_meminfo mi;
    short sel = __dpmi_allocate_descriptors(1);    // successful
    InitVbe();
    SetVbeSurface(400,300,8);         // these set up VESA 400x300x256 mode
ok (LFB)
    mi.size=vib.TotalMemory*65536;    // this is 2048K
    mi.address=mib->PhysBasePtr;      // this is 0xE0000000
    __dpmi_physical_address_mapping(&mi);    // successful
    __dpmi_set_segment_base_address(sel, mi.address);
    __dpmi_set_segment_limit(sel, 120000);
    __dpmi_set_descriptor_access_rights(sel, 0x4092);  // successful
    _farsetsel(sel);                  // that causes GPF
    _farnspokeb(0,15);
    getch();
    ShutDown();                       // back to text mode
}

how can _farsetsel cause a GPF, when eveything is valid? i debugged
the program, and a 'mov fs,bx' instruction causes it, where bx is
0x12f - seems correct, doesn't it? Then, what can be the problem?
Please help.
Thanks.