Re: MPC8360E Linux and 2.6.19.2

["Russell McGuire" <rmcguire@uwbt.com>]

I have tracked my 'lockup' to a specific line in /powerpc/kernel/prom.c

In the function: __init unflatten_device_tree(void)
On line:

mem = lab_alloc(size + 4, __alignof__(struct device_node));
mem = (unsigned long) __va(mem);

((u32 *)mem[size / 4] = 0xdeadbeef;


This is causing a lockup when 0xdeadbeef is written. I have no idea why...

My assumption would be that somehow the memory is not ready? Or BATS are not
setup correctly? Perhaps a LAW register?

Is this line dependent on having the DTS tree setup correctly? If so, how
big can the 'memory' node be in the DTS file? I have mine tried a single
bank of 256MB, and of 512MB <I have a single 512MB DIMM at the moment>

-Russ

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Original Message:

All,

Trying to boot up / debug my board with a Rev 1.2 MPC8360E. 

After the kernel launches from U-boot I receive no serial debug, and the
system hangs. 

I am running U-boot 1.1.6. Dirty <which does contains support for the 8360>,

I have walked through the DTS/blob file, after U-boot modifies it, <I turned
on all the debug info>, and can clearly see that the /chosen node, etc.. is
getting entered. My original DTS file already has all of the clock speeds
entered <modeled after the MPC8360xx.dts file that was already in the
DENX-2.6.19.2 kernel release>.

I have limited debug ability via some GPIO leds on our board, I can see that
the kernel starts to run and at least gets to the point where it clears all
the BATs <powerpc/boot/head_32.S and setup_32.c>, at which point I lose
access to the IO space and can no longer write out to the debug lights.
Unfortunately I do not have access to a COP debugger at this point. It
doesn't seem to get to the platform files, or at least I can get the GPIO
access inside the IMMR space to work correctly.

Does anyone have any suggestion per software only debug method that might be
enabled? Or a way to temporarily hack the early serial output so I can see
what is going on?

-Russ