Greetings Sangmoon, My apologies, I thought that most PPC based chips had configuration or status registers that were not in the SPR space (i.e. IMMR based regs). A little research says this is not the case. As I understand it (with thanks to Wolfgang) Linux reserves memory space below 80000000 for user applications. In my case I had my IMMR based registers mapped below this value, and the kernel was setting mapping for this space to virtual = physical, which caused my problem. You may have the same issue with your serial port, it would be worth a try to move it to high memory and see if this resolves your problem.
Best of luck, Derrik Weeks -----Original Message----- From: Sangmoon Kim [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 26, 2002 8:31 PM To: Derrik Weeks; linuxppc-embedded Subject: Re: execve system call question Hi Derrik Weeks! > IMMR needs to be located in high memory above F0000000. The MPC755 doesn't have an IMMR. If it is because all the I/O should be locaced above F0000000, please let me know. The serial port of my board is located at 0x78000000. > kernel will crash whether you're running NFS or a ram disk. You are right I tried ramdisk but kernel crashed. Thank you for the reply. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
