Reboot Command Makes kernel to hang (MPC8560)
ma.harounansari at gdatech.co.in
Thu Aug 2 16:48:16 EST 2007
Hi Koller & Kumar
Thanks for ur reply.
Is there a way to reset the full chip (MPC8560) whenever core reset occurs
(using hardware or software) ??
Haroun Ansari M A
----- Original Message -----
From: "Kumar Gala" <galak at kernel.crashing.org>
To: "Clemens Koller" <clemens.koller at anagramm.de>
Cc: "Ansari" <ma.harounansari at gdatech.co.in>; <linuxppc-embedded at ozlabs.org>
Sent: Tuesday, July 31, 2007 7:41 PM
Subject: Re: Reboot Command Makes kernel to hang (MPC8560)
On Jul 31, 2007, at 6:44 AM, Clemens Koller wrote:
> Hi, Ansari!
> Ansari schrieb:
>> Hi Kumar,
>> First of all thanks for ur reply .
>> Even i went through the linux source . And i have observe that the
>> reboot command used to hard reset the core . I have few doubts can u
>> please clarify me.
>> 1. Is there any way to reset the full chip with out using any external
>> signal (MPC8560) ? (like any register that can be used for reseting the
> I RTFM:
> It should be the bits RST[1:0] in the Debug Control Register 0 (DBCR0).
This only resets the core on the 8560.
> I didn't find details how the external signals are affected: HRESET_REQ#
> and friends.
> The HRESET_REQ# is usually fed back to the CPU's HRESET#.
> So if the HRESET_REQ# gets asserted by writing to above registers it
> should really bring
> down the CPU, it's internal as well as it's external components, which
> are usually
> connected to a replication of that signal.
This is roughly correct. The only way on 8560 to generate
HRESET_REQ# is to cause a core watchdog timeout.
> However the existence of cpm2_reset() and a qe_reset() (QuiccEngine?)
> in the code tells me that the above expectations could be wrong.
> Would be nice to have that verified by some hardware guys from
cpm2_reset/qe_reset are more related to SW than any HW reset.
>> 2. Even same reboot command works fine for MPC8540 Processor ?.
> ...because it doesn't have a cpm ?
That's more luck than anything else.
>> 3. what are the factors that makes ramdisk hangs . When its
>> uncompressing ?
> Well, side effects ?
> Clemens Koller
> R&D Imaging Devices
> Anagramm GmbH
> Rupert-Mayer-Straße 45/1
> Linhof Werksgelände
> D-81379 München
> Fax 089-741518-19
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