Date: Fri, 2 Apr 1999 08:00:15 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Kecskemeti Balazs <balazs AT tiszanet DOT hu>
cc: djgpp AT delorie DOT com
Subject: Re: _farsetsel?
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On Wed, 31 Mar 1999, Kecskemeti Balazs wrote:

>     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);
                                    ^^^^^^
Where did that 120,000 come from?  The size of the memory is 
vib.TotalMemory*65535 (which is 2MB as you say in the comment).  So what 
kind of number is 120000?

Also, please note that the limit should be 1 less than the size, so you 
need to subtract 1.

> how can _farsetsel cause a GPF, when eveything is valid?

Please always post the entire regsiters' dump and call traceback when you 
report crashes.  This is very important information you omitted.

> i debugged
> the program, and a 'mov fs,bx' instruction causes it, where bx is
> 0x12f - seems correct, doesn't it?

One of the possible reasons could be the access rights you define.  
Please post the details why 0x4092 is the right value in your case.