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Date: Mon, 27 Aug 2001 14:14:34 +0200
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
From: Pierre Muller <muller AT cerbere DOT u-strasbg DOT fr>
Subject: UMB access with %gs selector
Cc: djgpp-workers AT delorie DOT com
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At 12:14 11/07/01 , Eli Zaretskii a écrit:
>Per Andrew's suggestion, I've committed the attached below.
>
>2001-07-10  Eli Zaretskii  <eliz AT is DOT elta DOT co DOT il>
>
>         * go32-nat.c (info_dos_cmdlist): New variable.
>         (go32_info_dos_command): New function.
>         (_initialize_go32_nat): Convert all DOS-specific commands into
>         subcommands of "info dos".  Suggested by Andrew Cagney
>         <ac131313 AT redhat DOT com>.

   Using these new features of GDB on a win95
with a CVS compiled GDB for djgpp target, I noticed that
the selector for Dos memory
(selector stored in $gs at startup)
with base 0x00000000 and limit 0x0010ffff
is declared as a 16 bit Data register!

    Doesn't this mean that the higher part of a index is not used?
(i.e. if  $esi contain 0x10008,
will
    movl  %gs:(%esi),%eax
load into %eax
the content of linear address 0x10008 or 0x00008 ??)

Can we really access to UMB area with a 16 bit selector ?

By the way,
thanks Eli for having added this to GDB !



Pierre Muller
Institut Charles Sadron
6,rue Boussingault
F 67083 STRASBOURG CEDEX (France)
mailto:muller AT ics DOT u-strasbg DOT fr
Phone : (33)-3-88-41-40-07  Fax : (33)-3-88-41-40-99