From mboxrd@z Thu Jan 1 00:00:00 1970 In-Reply-To: Date: Wed, 10 Feb 1999 12:49:19 +0100 To: "Michael R. Zucca" , linuxppc-dev@lists.linuxppc.org From: BenH Subject: Re: NuBus PowerMacs and PDM video Message-Id: <19990210124919.012660@mail.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Tue, Feb 9, 1999, Michael R. Zucca wrote: >You just need to know the physical base address of the frame buffer. >Once you know that you can just rewrite the page tables to put the >frame buffer anywhere you'd like it. I was thinking about the machines that store the framebuffer in main memory (I beleive the 6100 does this). In this case, several people told me that the physical address was actually 0. Anyway, I now have some code to mess with the video controller, so I will be able to work around this problem. >You need to write a program under MacOS that will find a physical address >for a given virtual address. You'll probably need to do this in assembly >or there may even be a toolbox call that will do this for you. There is a MacOS call for logical->physical mappings. The base address sent by BootX to the kernel is already a physical address (actually both are sent with BootX >= 1.0.2b1) -- E-Mail: BenH. Web : [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. To unsubscribe from linuxppc-dev, send ]] [[ the message 'unsubscribe' to linuxppc-dev-request@lists.linuxppc.org ]]