RE: BDI2000 and failed MMU translations

Ok,

This still doesn't solve my problem.

In the Makefile:
	CONFIG_KERNEL = -g -ggdb

In mpc860.cnf for the bdi:
	MMU XLAT 0xc0000000 (this is the default BTW)
	PTBASE	0xf0
	BREAK SOFT

On the BDI:
	bi 0xc0157640 (start_kernel)
	go
	<breakpoint>

Now, start gdb w/ vmlinux
(gdb) target remote bdi:2001
(gdb) br scc_enet_init

On the BDI it says:
*** MMU: address translation for 0xC015ECB8 failed
(gdb) c
Continuing.
warning: Cannot insert breakpoint 1:
Error accessing memory address 0xc015ecb8: Operation not permitted

I'm using gdb 5.0.

Does this shed any more light?

TIA Dan and all,

Regards,

Matt

-----Original Message-----
From: Dan Malek [mailto:dan@embeddededge.com]
Sent: Wednesday, January 23, 2002 5:51 PM
To: Gessner, Matt
Cc: 'Linux PPC'
Subject: Re: BDI2000 and failed MMU translations


Gessner, Matt wrote:

quoted

It's straight 2_4.  I wasn't stopping at start_kernel though.

You don't need to stop anywhere unless there are some breakpoints
you want to set for early debug.

quoted

I don't have PTBASE set up.

You need:
	MMU XLAT 0xc0000000
	PTBASE 0x000000f0

The newer kernels initialize the page table pointers for the BDI2000,
so ignore comments about stopping and setting values.  We went through
several iterations of implementation, so anything written about how to
do this manually is probably wrong :-).

quoted

...... I'm going to
break at start kernel FIRST, then connect with BDI, then
see if I can look at my data.

How do you break and then connect the BDI?  You need the BDI
connected to set and trap the breakpoint.

Have fun.


	-- Dan

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