From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: From: Steven Blakeslee To: "'Paul Miller'" , linuxppc-embedded@lists.linuxppc.org Subject: RE: 405EP peripheral memory access Date: Wed, 29 Oct 2003 09:31:52 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: I would recommend you get the following books. Embedded Linux: Hardware, Software, and Interfacing by Craig Hollabaugh Linux Device Drivers, 2nd Edition by Alessandro Rubini, Jonathan Corbet Building Embedded Linux Systems by Karim Yaghmour -----Original Message----- From: Paul Miller [mailto:pmiller9@users.sourceforge.net] Sent: Wednesday, October 29, 2003 9:08 AM To: linuxppc-embedded@lists.linuxppc.org Subject: 405EP peripheral memory access Hi, I am new to Linux embedded programming. I have experience programming microcontrollers and DSPs without an operating system, so I have some idea what I'm doing. Anyhow, I'm trying to use the peripheral memory bus on my 405EP CerfCube from Intrinsyc. Does anyone have an example that I can work from? To setup the memory's timings, I need access to the DCR register. In the PowerPC datasheet it says to use assembly instructions mtdcr and mfdcr. I don't know much about assembly, but I found a kernel patch that uses these functions. So, working off this patch, I tried making a simple program to read these registers. When I run it, Linux reports an "Illegal instruction" and doesn't let me access the register. Does access to this bus need to be done in "kernel mode"? If so, where can I find more information about writing a kernel driver? Ideally, I'd like to just open a device file and read/write to the bus. Thanks! -Paul ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/