From:	Corelli Marco <mcorelli AT gtwparc DOT padova DOT ccr DOT it>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Accesing from 0xFFFF:F000 to 0xFFFF:FFFF physical memory address
Date:	Fri, 13 Oct 2000 17:18:07 +0200
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To:	djgpp AT delorie DOT com
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> Didn't you say in your original message that the address you wanted to
> map was at FFFC:0000 to FFFF:FFFF?  Are those real-mode segment:offset
> addresses, or did you mean to say FFFC0000, a 32-bit physical address?
> There's a big difference between these two alternatives.

It's a physical address from FFFC000 to FFFFFFFF!!

> The above setup of the FS register is correct for 32-bit physical
> address FFFC0000, but incorrect for FFFC:0000.
>
> > byte_read = _farpeekb ( selector, i ) ;

> Please tell what is the first value of i for which the program
> crashes.

It's crash at first value : zero!!!

> >         __dpmi_physical_address_mapping( &mem ) ;
> >         selector = __dpmi_allocate_ldt_descriptors ( 1 ) ;
> >         __dpmi_set_segment_base_address ( selector, mem.address ) ;
> >         __dpmi_set_segment_limit ( selector, mem.size - 1 ) ;
>
> Did all those functions succeed, or did some of them returned -1?

All function succeed!!! I test the result an it't != -1 !!!!

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