[U-Boot] mcf5445x watchdog support in U-Boot

[U-Boot] mcf5445x watchdog support in U-Boot

[Matthew Lear]

Hi TsiChung et al,

I was wondering if there are plans to support and utilise the watchdog in the
mcf5445x devices within U-Boot?

I've ported a kernel driver from the bitshrine gpp
(http://www.bitshrine.org/gpp/linux-2.6.25-mcfv4e-watchdog.patch) so that it
hooks into my 54455 hw (Freescale EVB), however I'd like to configure and enable
the watchdog in U-Boot with the intention that once Linux starts, the
responsibility of kicking the watchdog resides with a user space app -> driver.

Thoughts?

Much appreciated.
--  Matt

[U-Boot] mcf5445x watchdog support in U-Boot

[Liew Tsi Chung-R5AAHP]

Matt,

Yes. I am planning to enable watchdog in mcf5445x in u-boot. Need to
investigate more in booting linux and the transition to starting the
linux kernel of watchdog behavior to make sure it is not causing problem
to the linux kernel.

Best Regards,
TsiChung


-----Original Message-----
From: Matthew Lear [mailto:matt at bubblegen.co.uk] 
Sent: Monday, June 15, 2009 7:59 AM
To: Liew Tsi Chung-R5AAHP; u-boot at lists.denx.de
Subject: mcf5445x watchdog support in U-Boot

Hi TsiChung et al,

I was wondering if there are plans to support and utilise the watchdog
in the mcf5445x devices within U-Boot?

I've ported a kernel driver from the bitshrine gpp
(http://www.bitshrine.org/gpp/linux-2.6.25-mcfv4e-watchdog.patch) so
that it hooks into my 54455 hw (Freescale EVB), however I'd like to
configure and enable the watchdog in U-Boot with the intention that once
Linux starts, the responsibility of kicking the watchdog resides with a
user space app -> driver.

Thoughts?

Much appreciated.
--  Matt

[U-Boot] mcf5445x watchdog support in U-Boot

[Matthew Lear]

Hi TsiChung,

I can supply you my patch for a watchdog driver implementation for 5445x
to test with if you like? I've not fed it back to Freescale yet. Will do
though. It's based on 2.6.29.

Is there a mechanism to allow U-Boot to indicate to Linux that it has
enabled the watchdog (eg as part of the bd_info struct maybe)? Just a
thought... It could then be kicked at kernel arch init and then repeatedly
by Linux user space via /dev/watchdog if required by the application. The
reason I suggested kicking the watchdog in arch init is to give Linux a
chance to boot (kernel and user) before the watchdog times out. Obviously
several things could prevent this (eg tasks that take time before user
space starts for example fsck etc).

I'm sure other U-Boot developers/maintainers have thought about this..?
Thoughts?

In any case, I need to enable the watchdog in U-Boot for a mcf54451 based
platform because need it in our system (we're using an mcf54455 evb as
reference hw). I'm happy to help in the development / testing etc. Please
just let me know.

Best regards,
--  Matt


> Matt,
>
> Yes. I am planning to enable watchdog in mcf5445x in u-boot. Need to
> investigate more in booting linux and the transition to starting the
> linux kernel of watchdog behavior to make sure it is not causing problem
> to the linux kernel.
>
> Best Regards,
> TsiChung
>
>
> -----Original Message-----
> From: Matthew Lear [mailto:matt at bubblegen.co.uk]
> Sent: Monday, June 15, 2009 7:59 AM
> To: Liew Tsi Chung-R5AAHP; u-boot at lists.denx.de
> Subject: mcf5445x watchdog support in U-Boot
>
> Hi TsiChung et al,
>
> I was wondering if there are plans to support and utilise the watchdog
> in the mcf5445x devices within U-Boot?
>
> I've ported a kernel driver from the bitshrine gpp
> (http://www.bitshrine.org/gpp/linux-2.6.25-mcfv4e-watchdog.patch) so
> that it hooks into my 54455 hw (Freescale EVB), however I'd like to
> configure and enable the watchdog in U-Boot with the intention that once
> Linux starts, the responsibility of kicking the watchdog resides with a
> user space app -> driver.
>
> Thoughts?
>
> Much appreciated.
> --  Matt
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
>
>

[U-Boot] mcf5445x watchdog support in U-Boot

[Matthew Lear]

Hello TsiChung.

I have added watchdog support in U-Boot for MCF5445x devices using the
M54455 EVB platform to test. I can send you a patch if you wish (the
timeout is hard coded to 16 secs at the moment)?

However, I am having trouble when U-Boot starts Linux in the case when the
watchdog has been enabled in U-Boot. Basically, Linux seems to crash
before it gets a chance to print anything on the console - but, control
appears to have left U-Boot.

Building U-Boot with debug, it displays:

## Transferring control to Linux (at address 40020000) ...
BIV

Then it's dead after which the watchdog times out and causes a cpu reset.

Building U-Boot without debug I get the following:

*** Unexpected exception ***
Vector Number: 4  Format: 04  Fault Status: 0

PC: 4fdbfdc8    SR: 00002700    SP: 4fd72a64
D0: 00000004    D1: 000003f9    D2: 4fdb4202    D3: 004fa3da
D4: 00000000    D5: 4fdc7c8c    D6: 122c0034    D7: 4fd82f76
A0: 4033cb98    A1: 4025aa39    A2: 40020000    A3: 4fdbfdc8
A4: 00000000    A5: 4fdc5800    A6: 4fd72afb

*** Please Reset Board! ***

Then again, the watchdog times out and causes a cpu reset.

It definitely appears as though Linux has been started but I cannot tell
what has actually happened. I think it's possible that something in the
Linux setup has caused (or contributed to) the crash. The problem does not
happen if the watchdog support is disabled by #undefining CONFIG_WATCHDOG.

It certainly seems that U-Boot is not responsible for the crash. Do you
have any thoughts on this? I'd appreciate a bit of help.

Rgds,
--  Matt


> Hi TsiChung,
>
> I can supply you my patch for a watchdog driver implementation for 5445x
> to test with if you like? I've not fed it back to Freescale yet. Will do
> though. It's based on 2.6.29.
>
> Is there a mechanism to allow U-Boot to indicate to Linux that it has
> enabled the watchdog (eg as part of the bd_info struct maybe)? Just a
> thought... It could then be kicked at kernel arch init and then repeatedly
> by Linux user space via /dev/watchdog if required by the application. The
> reason I suggested kicking the watchdog in arch init is to give Linux a
> chance to boot (kernel and user) before the watchdog times out. Obviously
> several things could prevent this (eg tasks that take time before user
> space starts for example fsck etc).
>
> I'm sure other U-Boot developers/maintainers have thought about this..?
> Thoughts?
>
> In any case, I need to enable the watchdog in U-Boot for a mcf54451 based
> platform because need it in our system (we're using an mcf54455 evb as
> reference hw). I'm happy to help in the development / testing etc. Please
> just let me know.
>
> Best regards,
> --  Matt
>
>
>> Matt,
>>
>> Yes. I am planning to enable watchdog in mcf5445x in u-boot. Need to
>> investigate more in booting linux and the transition to starting the
>> linux kernel of watchdog behavior to make sure it is not causing problem
>> to the linux kernel.
>>
>> Best Regards,
>> TsiChung
>>
>>
>> -----Original Message-----
>> From: Matthew Lear [mailto:matt at bubblegen.co.uk]
>> Sent: Monday, June 15, 2009 7:59 AM
>> To: Liew Tsi Chung-R5AAHP; u-boot at lists.denx.de
>> Subject: mcf5445x watchdog support in U-Boot
>>
>> Hi TsiChung et al,
>>
>> I was wondering if there are plans to support and utilise the watchdog
>> in the mcf5445x devices within U-Boot?
>>
>> I've ported a kernel driver from the bitshrine gpp
>> (http://www.bitshrine.org/gpp/linux-2.6.25-mcfv4e-watchdog.patch) so
>> that it hooks into my 54455 hw (Freescale EVB), however I'd like to
>> configure and enable the watchdog in U-Boot with the intention that once
>> Linux starts, the responsibility of kicking the watchdog resides with a
>> user space app -> driver.
>>
>> Thoughts?
>>
>> Much appreciated.
>> --  Matt
>> _______________________________________________
>> U-Boot mailing list
>> U-Boot at lists.denx.de
>> http://lists.denx.de/mailman/listinfo/u-boot
>>
>>
>
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
>
>