RE: Reset for MPC8245

-----Original Message-----
From: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]On Behalf Of
Arunachalam, Saravanan
Sent: Tuesday, June 01, 2004 1:57 PM
To: linuxppc-embedded@lists.linuxppc.org
Subject: Reset for MPC8245



Hi,

I am trying to do Internal Hard Reset from the kernel for
MPC8245 based
custom board. I tried the Machine check stop approach but it doesn't
work. I am able to successfully do from the u-boot bootloader. The
following code generates Instruction Exception at the instruction that
turns off MMU.

msr = mfmsr();

/* Interrupts and MMU off */
__asm__ __volatile__ ("mfmsr    %0":"=r" (msr));

msr &= ~0x1030;
__asm__ __volatile__ ("mtmsr    %0"::"r" (msr)); <---
Instruction Except
addr = 0xfff00100;
((void (*)(void)) addr) ();

If anyone has a solution to this, I would greatly appreciate it.

Thanks
Arun

I don't know if it is a solution, but I'm suspicious of the line " addr = 0xfff00100;".  The key to doing a machine check reset is (a) reconfiguring the MSR to do a reset on a machine check and (b) causing a machine check to occur.  Item (b) is typically done by jumping to a memory location that doesn't exist.  I suspect that in your case, location 0xfff00100 _does_ exist: it is the reset vector in your ROM.

Try setting addr to an invalid location.

gvb


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