Subject: Re: changed files: 'src/sys/arch/i386/include reg.h'
To: Charles Hannum <>
From: John Brezak <>
List: source-changes
Date: 01/01/1994 14:47:47
>    (though if support for them is ever put in here, they should be,
>    but for i486-en only...
> I don't follow your logic there.  My 386 certainly thinks it knows about
> FS and GS, and theoretically we should be making them as accessible as
> any other registers.  Now it's true that we don't really use them for any
> `normal' applications, but that's not an adequate answer; who the Hell
> knows what, e.g., WINE programs might do, and there's no documentation
> that says their use is forbidden.

Right now the kernel will clobber GS and FS without saving them for the user.
Also WINE is a Win16 emulator. Win16 uses 286 instructions and thus will not
reference FS and GS. Although Win32 support is not far off.

Prehaps there should be some "lazy" context saving code for gs and fs ? Maybe
just go for a real TSS per process and be done with it ?

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