i tried some different versions, including mid2008 ones, and i work now 
mainly with the latest svn version.

i forgot :

an example of the CP15 registers :

data
CP15(0)    41029402
CP15(1)    C000107D >>
CP15(2)    00000015 >> D region 0,2,4 cachable
CP15(3)    00000017
CP15(5)    0000FEFF
CP15(6)    00000027  08000035  08000031  20000033  2400002B  38000035 
2201401B  22020021
CP15(7)    00000000
CP15(9)    00000000
CP15(F)    00000000
instruction
CP15(0)    0F0F10F1
CP15(2)    00000015 >> D region 0,2,4 cachable
CP15(5)    0000FEFF
CP15(6)    00000027  08000035  08000031  20000033  2400002B  38000035 
2201401B  22020021
CP15(7)    00000000
CP15(9)    00000000



Cory Walker a écrit :
> You did compile openocd from source right? the repo has an outdated
> version (commit 1147 when the current is 2294)
> 
> On Sat, 2009-06-20 at 17:28 +0900, tof wrote:
>> Hello
>>
>>
>> some news :
>>
>> We have now a working ARM core in debug. The problem is., as soon as TCK 
>> gets closcked, all the memories and peripherials are disconnected from 
>> the micro. (the nano freezes)
>>
>> I cannot acess any memory, so it's not possible to dump the mask rom.
>> Also, between the clocking of the jtag, and the efffective stopping of 
>> the execution, many instruction can get executed, leading to random 
>> effects. These instructions are usually a fixed opcode.
>>
>> Useful infos we can get :
>> - all core registers, at any time (small chance of corruption)
>> - CP15 registers : R/W acess : config of the memory system...
>> - some sparse data left in the data cache. Unfortunately the instruction 
>> cache cannot be acessed, and the caches are not active during the first 
>> phase of the boot (only activated when the screen light turns on)
>> - the memory map is guessed to be nearly the same than the 8700
>> - the NOR flash is physically acessed, even if the value does not arrive 
>> to the processor.
>> - i did not found a scanchain 3 (1 bit only ?)
>>
>>
>> I suspect 2 things
>> a) some protection scheme introduced by samsung externally to the core
>> b) some problem from openocd for clocking the load instructions at 
>> system speed.
>>
>>
>> For acessing the memory, the debugger needs to follow a special 
>> procedure, so that the core resynchronizes to sys. clock, instead of the 
>> JTAG clock. This could be an issue. Normally openocd handles this, but 
>> there are far more users of the ARM920 than the ARM940 (with different 
>> memory systems)
>>
>> To check that, we could make a trial with a commercial JTAG debugger+SW
>> does someone here own this kind of hardware ?
>>
>>
>> some data examples :
>>
>> http://f4eru.free.fr/nano2/log/
>>
>>
>> the dump with 4 words is the Dcache data
>>
>> the random patterns with most time 16bits content are the corrupt values
>>
>>
>>
>> Cory Walker a écrit :
>>> Also, could you explain the difference between red and pink on your  
>>> annotations?
>>>
>> the pink is just for interesting signals...
>>
>>
>>
>>
>> sto
>>
>>
>> _______________________________________________
>> Linux4nano-dev mailing list
>> [email protected]
>> https://mail.gna.org/listinfo/linux4nano-dev
>> http://www.linux4nano.org
> 
> 
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