BDI2000 and failed MMU translations
Gessner, Matt
mattg at aiinet.com
Thu Jan 24 09:55:13 EST 2002
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 at 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:
>
> > 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.
>
> > 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 :-).
>
> > ...... 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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