Hi Flavio, on 862 the internal memory mapped registers are not like plane memory. Only several addresses can actualy be accessed. If you try no access an non existant register address you cause a bus error. For that reason you have to consult the manual before you access any address in the IMMR area and in most cases a simple dump tries to access an area that is to large to avoid invalid accesses.
Regards, Stephan > -----Original Message----- > From: owner-linuxppc-embedded at lists.linuxppc.org > [mailto:owner-linuxppc-embedded at lists.linuxppc.org]On Behalf Of Flavio > Pereira > Sent: Mittwoch, 5. Februar 2003 13:48 > To: LinuxPPC-Embedded > Subject: Accessing MPC862 registers > > > > Hi all > > I'm hoping that someone can help me here. I'm using the TQM8xxL module > with a MPC862 processor on board. With minor changes to the pin > configurations for the ethernet controller I have gotten U-boot and > Linux to work without any issues. However from my BDI2000 shell, with my > IMMR set to 0xFFF00000 (confirmed), I cannot do memory dumps for the > region 0xFFF00000 - 0xFFF02000. From FFF02000 (DP-RAM) the memory > accesses seem fine. The same goes for the u-boot shell. Obviously u-boot > and linux have managed to access these registers, else the system would > not start? How do I go about doing direct memory accesses to the MPC's > registers which are located from 0xFFF00000 to 0xFFF00DFF from either > u-boot or the BDI shell? > > Regards > Flavio Pereira > > > > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
