From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ian Pratt" Subject: RE: EPS Signature Date: Mon, 5 Feb 2007 02:52:39 -0000 Message-ID: <8A87A9A84C201449A0C56B728ACF491E04F423@liverpoolst.ad.cl.cam.ac.uk> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: Content-class: urn:content-classes:message List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Kaushik Barde , Xen devel list List-Id: xen-devel@lists.xenproject.org > We want to access the EBDA Entry Point Signature at 40:0E for our DOM-0 > through a driver, > We noticed that driver is trying to read from a pseudo physical location > and not the physical machine RAM location. Hence it's not getting the > proper value. But if we have to read from the machine RAM location we can > use ( virt_to_bus or bus_to_virt) per dev_list comments. >=20 > But this area is under the control of hypervisor. I do not know if we can > ioremap these pages ( those which belong to hypervisor). >=20 > I am trying to see if we can be able to get to the 40:0E address. And get > the correct EPS signature Dom0 already has the bottom 1MB of physical ram mapped. You can use the poorly named isa_bus_to_virt() Ian