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 the repo has an outdated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


_______________________________________________
Linux4nano-dev mailing list
[email protected]
https://mail.gna.org/listinfo/linux4nano-dev
http://www.linux4nano.org

Reply via email to