[U-Boot-Users] PPC440GX reset command doesn't work

[U-Boot-Users] PPC440GX reset command doesn't work

[Andrew Wozniak]

We have a custom PPC440GX board running a ported version of U-Boot based
on the OCOTEA codebase. Most U-Boot commands are working - life is good.

Except for the 'reset' command. The do_reset() source code at
cpu/ppc4xx/cpu.c appears to be the function for doing the reset via the
PPC "debug control register". The PPC manual shows that a cpu reset is
possible thru this register, but I'm a PPC assembly newbee and need to
figure it out the macros in the cpu.c source code.

Just wondering if anyone else with a PPC440 target had any special
modifications to make 'reset' work.

Thank you.

[U-Boot-Users] PPC440GX reset command doesn't work

[Andrew Wozniak]

Andrew Wozniak wrote:
> We have a custom PPC440GX board running a ported version of U-Boot based
> on the OCOTEA codebase. Most U-Boot commands are working - life is good.
> 
> Except for the 'reset' command. The do_reset() source code at
> cpu/ppc4xx/cpu.c appears to be the function for doing the reset via the
> PPC "debug control register". The PPC manual shows that a cpu reset is
> possible thru this register, but I'm a PPC assembly newbee and need to
> figure it out the macros in the cpu.c source code.
> 
> Just wondering if anyone else with a PPC440 target had any special
> modifications to make 'reset' work.

Ok, understand the assembly macro (except for the ::: "r3"). Must have
something to do with do_reset args?

Anyway, it appears that a PPC "system reset" does not work as
implemented via DBCR0 value 0x30000000.

If I change the value to 0x20000000 to do a "chip reset", the U-Boot
'reset' command works!

Is this an appropriate solution or might our hardware design have a flaw?

Thanks for all suggestions.

> Thank you.

[U-Boot-Users] PPC440GX reset command doesn't work

[Travis B. Sawyer]

Andrew Wozniak wrote:
> Andrew Wozniak wrote:
> 
>> We have a custom PPC440GX board running a ported version of U-Boot based
>> on the OCOTEA codebase. Most U-Boot commands are working - life is good.
>>
<SNIP>
>> Just wondering if anyone else with a PPC440 target had any special
>> modifications to make 'reset' work.
> 
Nope, it just works, on 3 different 440gx targets I have.  The XES
XPedite1000, the Ocotea, and our custom hardware...


-travis

[U-Boot-Users] PPC440GX reset command doesn't work

[Andrew Wozniak]

Travis B. Sawyer wrote:
> Andrew Wozniak wrote:
> 
>> Andrew Wozniak wrote:
>>
>>> We have a custom PPC440GX board running a ported version of U-Boot based
>>> on the OCOTEA codebase. Most U-Boot commands are working - life is good.
>>>
> <SNIP>
> 
>>> Just wondering if anyone else with a PPC440 target had any special
>>> modifications to make 'reset' work.
>>
>>
> Nope, it just works, on 3 different 440gx targets I have.  The XES
> XPedite1000, the Ocotea, and our custom hardware...

hmmm.... will have to investigate further.

Could our problem be related to how our PPC is configured from serial
eeprom? Or might is be that DBCR (or some other control register) is
misconfigured - disallowing a "system reset"?

Thanks for confirming proper 'reset' operation as currently implemented.

> 
> -travis
> 
> 

[U-Boot-Users] PPC440GX reset command doesn't work

[Howard, Marc]

Try putting a scope/logic analyzer on your SYSRESET* line to see if it
is getting pulled down when you try to reset from U-Boot.

Marc W. Howard


> -----Original Message-----
> From: u-boot-users-admin at lists.sourceforge.net 
> [mailto:u-boot-users-admin at lists.sourceforge.net] On Behalf 
> Of Andrew Wozniak
> Sent: Tuesday, June 07, 2005 10:48 AM
> To: tsawyer+u-boot at sandburst.com
> Cc: U-Boot mailing list
> Subject: Re: [U-Boot-Users] PPC440GX reset command doesn't work
> 
> Travis B. Sawyer wrote:
> > Andrew Wozniak wrote:
> > 
> >> Andrew Wozniak wrote:
> >>
> >>> We have a custom PPC440GX board running a ported version 
> of U-Boot based
> >>> on the OCOTEA codebase. Most U-Boot commands are working 
> - life is good.
> >>>
> > <SNIP>
> > 
> >>> Just wondering if anyone else with a PPC440 target had any special
> >>> modifications to make 'reset' work.
> >>
> >>
> > Nope, it just works, on 3 different 440gx targets I have.  The XES
> > XPedite1000, the Ocotea, and our custom hardware...
> 
> hmmm.... will have to investigate further.
> 
> Could our problem be related to how our PPC is configured from serial
> eeprom? Or might is be that DBCR (or some other control register) is
> misconfigured - disallowing a "system reset"?
> 
> Thanks for confirming proper 'reset' operation as currently 
> implemented.
> 
> > 
> > -travis
> > 
> > 
> 
> 
> 
> -------------------------------------------------------
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> 

[U-Boot-Users] PPC440GX reset command doesn't work

[Andrew Wozniak]

Howard, Marc wrote:
> Try putting a scope/logic analyzer on your SYSRESET* line to see if it
> is getting pulled down when you try to reset from U-Boot.

Good point. But shouldn't the core and chip level reset still function,
independent of the external reset line?  The answer might be buried
somewhere in the PPC440 tech manuals.

I might also talk to our hardware guys about this.

> Marc W. Howard
> 
> 
> 
>>-----Original Message-----
>>From: u-boot-users-admin at lists.sourceforge.net 
>>[mailto:u-boot-users-admin at lists.sourceforge.net] On Behalf 
>>Of Andrew Wozniak
>>Sent: Tuesday, June 07, 2005 10:48 AM
>>To: tsawyer+u-boot at sandburst.com
>>Cc: U-Boot mailing list
>>Subject: Re: [U-Boot-Users] PPC440GX reset command doesn't work
>>
>>Travis B. Sawyer wrote:
>>
>>>Andrew Wozniak wrote:
>>>
>>>
>>>>Andrew Wozniak wrote:
>>>>
>>>>
>>>>>We have a custom PPC440GX board running a ported version 
>>
>>of U-Boot based
>>
>>>>>on the OCOTEA codebase. Most U-Boot commands are working 
>>
>>- life is good.
>>
>>><SNIP>
>>>
>>>>>Just wondering if anyone else with a PPC440 target had any special
>>>>>modifications to make 'reset' work.
>>>>
>>>>
>>>Nope, it just works, on 3 different 440gx targets I have.  The XES
>>>XPedite1000, the Ocotea, and our custom hardware...
>>
>>hmmm.... will have to investigate further.
>>
>>Could our problem be related to how our PPC is configured from serial
>>eeprom? Or might is be that DBCR (or some other control register) is
>>misconfigured - disallowing a "system reset"?
>>
>>Thanks for confirming proper 'reset' operation as currently 
>>implemented.
>>
>>
>>>-travis
>>>
>>>
>>
>>
>>
>>-------------------------------------------------------
>>This SF.Net email is sponsored by: NEC IT Guy Games.  How far 
>>can you shotput
>>a projector? How fast can you ride your desk chair down the 
>>office luge track?
>>If you want to score the big prize, get to know the little guy.  
>>Play to win an NEC 61" plasma display: http://www.necitguy.com/?r=20
>>_______________________________________________
>>U-Boot-Users mailing list
>>U-Boot-Users at lists.sourceforge.net
>>https://lists.sourceforge.net/lists/listinfo/u-boot-users
>>
> 
> 

[U-Boot-Users] PPC440GX reset command doesn't work

[Mészáros Lajos]

The RESET pin is pulled down during internal reset.
I know only the 8xx and 82xx family but IMHO the 440
is (should be) the same.
The answer IS buried somewhere in the manuals.
    Ludwig

...
> 
> Howard, Marc wrote:
> > Try putting a scope/logic analyzer on your SYSRESET* line 
> to see if it
> > is getting pulled down when you try to reset from U-Boot.
> 
> Good point. But shouldn't the core and chip level reset still 
> function,
> independent of the external reset line?  The answer might be buried
> somewhere in the PPC440 tech manuals.
> 
> I might also talk to our hardware guys about this.
> 
...
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[U-Boot-Users] PPC440GX reset command doesn't work

[Renaud Barbier]

Just saw that old email. I am haveing the sme problem with my 440GX.

Have you found any clue of why a system reset does not work?

Andrew Wozniak wrote:

>Andrew Wozniak wrote:
>  
>
>>We have a custom PPC440GX board running a ported version of U-Boot based
>>on the OCOTEA codebase. Most U-Boot commands are working - life is good.
>>
>>Except for the 'reset' command. The do_reset() source code at
>>cpu/ppc4xx/cpu.c appears to be the function for doing the reset via the
>>PPC "debug control register". The PPC manual shows that a cpu reset is
>>possible thru this register, but I'm a PPC assembly newbee and need to
>>figure it out the macros in the cpu.c source code.
>>
>>Just wondering if anyone else with a PPC440 target had any special
>>modifications to make 'reset' work.
>>    
>>
>
>Ok, understand the assembly macro (except for the ::: "r3"). Must have
>something to do with do_reset args?
>
>Anyway, it appears that a PPC "system reset" does not work as
>implemented via DBCR0 value 0x30000000.
>
>If I change the value to 0x20000000 to do a "chip reset", the U-Boot
>'reset' command works!
>
>Is this an appropriate solution or might our hardware design have a flaw?
>
>Thanks for all suggestions.
>
>  
>
>>Thank you.
>>    
>>
>
>
>
>-------------------------------------------------------
>This SF.Net email is sponsored by: NEC IT Guy Games.  How far can you shotput
>a projector? How fast can you ride your desk chair down the office luge track?
>If you want to score the big prize, get to know the little guy.  
>Play to win an NEC 61" plasma display: http://www.necitguy.com/?r=20
>_______________________________________________
>U-Boot-Users mailing list
>U-Boot-Users at lists.sourceforge.net
>https://lists.sourceforge.net/lists/listinfo/u-boot-users
>
>  
>