Date: Thu, 6 Sep 2007 11:28:03 +0200 From: "Die Gestalt" <die.gestalt@gmail.com> To: freebsd-drivers@freebsd.org Subject: Re: Physical address Message-ID: <5bf3e10d0709060228s44f9a3efl886512e186c86448@mail.gmail.com> In-Reply-To: <5bf3e10d0709050757vfb87ef4m499339ff0bb4724d@mail.gmail.com> References: <5bf3e10d0709050757vfb87ef4m499339ff0bb4724d@mail.gmail.com>
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What I did is start a VMWare running FreeBSD, boot and freeze at logon, open the vmem file in a Hex editor and see that there is stuff between 0x1000 - 0x4000. The memory is clear (as expected) after 0x4000 till the kernel (after the first megabyte). I have no idea what it is and where it comes from, especially since I think pages are cleared when mapped, right? That would mean that it cannot be a residue from the boot sequence (unless I'm wrong). Any idea? -- Die Gestalt On 9/5/07, Die Gestalt <die.gestalt@gmail.com> wrote: > Hi all, > > I would like to know if there are drivers in a vanilla FreeBSD kernel > that write to *physical* memory addresses between 0x1000 and 0x4000. > > From what I inderstand the region between 0x1000 and the first > megabyte is mapped read only, but that doesn't prevent you from > accessing the region if you really want to. > > Hope my question makes sense. > > -- > > Die Gestalt >
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