7400 mmu_init problem
Matt Porter
mporter at mvista.com
Sat Apr 6 03:28:54 EST 2002
On Fri, Apr 05, 2002 at 05:45:08AM -0500, Greg Griffes wrote:
>
> Hello,
>
> I am trying to port linuxppc_2_4_devel to a custom 750 design.
> Using the GNU binutils and gcc-core-2.95.3 tools.
7400 (subject line) or 750? :) It doesn't matter though.
> After ppc_md.progress reports "MMU: exit" in mm/init.c::mmu_init()
> the kernel goes into panic() and dies there.
>
> I have been using a lousy, unreliable JTAG debugger. Today, I have a
> BDI2000 and will be learning how to use it and GDB :-))
Even with a bad debugger you should be able to dump log_buf to
see the oops message.
> Has anyone experienced this in the past?
If I had a nickel for every time...
> Does anyone have a rough idea of the cause of the problem?
> My guess is that it could be many possible problems, but, it has to
> be something that I did wrong in <my>_setup.c I haven't changed
> much in the kernel itself.
We can only guess since we don't know your hardware and can't see
your board specific code. However, you made it out of MMU_init
and most likely got to start_kernel:setup_arch. I can only guess
that you access an unmapped area in your <board>_setup_arch.
> The low level IO is mapped at 0xEC00_0000; could that be a problem?
What low level IO? Are you attempting to map and use it early on?
We need more details to help further.
> The kernel is configured very slim, could I be excluding necessary
> functionality?
Not really.
Regards,
--
Matt Porter
MontaVista Software, Inc.
mporter at mvista.com
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
More information about the Linuxppc-embedded
mailing list