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Date:      Sat, 18 Sep 2004 16:59:48 -0400
From:      John Baldwin <jhb@FreeBSD.org>
To:        "Poul-Henning Kamp" <phk@phk.freebsd.dk>
Cc:        cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/sys/boot/i386/boot2 boot2.c
Message-ID:  <200409181659.48310.jhb@FreeBSD.org>
In-Reply-To: <1860.1095491285@critter.freebsd.dk>
References:  <1860.1095491285@critter.freebsd.dk>

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On Saturday 18 September 2004 03:08 am, Poul-Henning Kamp wrote:
> In message <200409180207.i8I27044010045@repoman.freebsd.org>, John Baldwin
> writ
>
> es:
> >jhb         2004-09-18 02:07:00 UTC
> >
> >  FreeBSD src repository
> >
> >  Modified files:
> >    sys/boot/i386/boot2  boot2.c
> >  Log:
> >  A long, long time ago in a CVS branch far away (specifically, HEAD prior
> >  to 4.0 and RELENG_3), the BTX mini-kernel used paging rather than flat
> >  mode and clients were limited to a virtual address space of 16
> > megabytes. Because of this limitation, boot2 silently masked all physical
> > addresses in any binaries it loaded so that they were always loaded into
> > the first 16 Meg.  Since BTX no longer has this limitation (and hasn't
> > for a long time), remove the masking from boot2.  This allows boot2 to
> > load kernels larger than about 12 to 14 meg (12 for non-PAE, 14 for PAE).
>
> Does this also give us better space for isa_dma bounce buffers ?

Err, I don't see how it could.  This only affects how boot2 handles addresses 
in the executables it loads, it doesn't affect how the kernel manages memory 
at all.

-- 
John Baldwin <jhb@FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org



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