JTAG debugging the linux kernel on tegra3 platforms

JTAG debugging the linux kernel on tegra3 platforms

[Alexander Oh]

Hi!

I'm currently trying to debug a QuadMo747-X T30. I'm trying to update 
the versions of u-boot and linux kernel. I run into problems while 
booting the kernel (similar to [2], but I'm not sure whats going on yet) 
and was hoping to get some help here about JTAG debuggers.

I've seen that people are already running the flyswatter2 JTAG debuggers 
with the nvidia tegra2 [1]. Is this debugger also working with the 
nvidia tegra3? I found out that James Zhao has been working on OpenOCD 
to get the Tegra3 running. But I could not find any references or 
manuals to get it working. I'm not entirely sure that the debugger is 
compatible with tegra3 processors.

Is anybody here actually using a flyswatter2 debugger with a tegra3 
processor?

Alex

[1]: http://comments.gmane.org/gmane.linux.ports.tegra/6019
[2]: http://www.spinics.net/lists/linux-tegra/msg11085.html

Re: JTAG debugging the linux kernel on tegra3 platforms

[Stephen Warren]

On 03/26/2014 08:16 AM, Alexander Oh wrote:
> Hi!
> 
> I'm currently trying to debug a QuadMo747-X T30. I'm trying to update
> the versions of u-boot and linux kernel. I run into problems while
> booting the kernel (similar to [2], but I'm not sure whats going on yet)
> and was hoping to get some help here about JTAG debuggers.

Turning on earlyprintk is hopefully the simplest way to debug this; see
the details in the thread you linked to.

> I've seen that people are already running the flyswatter2 JTAG debuggers
> with the nvidia tegra2 [1]. Is this debugger also working with the
> nvidia tegra3? I found out that James Zhao has been working on OpenOCD
> to get the Tegra3 running. But I could not find any references or
> manuals to get it working. I'm not entirely sure that the debugger is
> compatible with tegra3 processors.
> 
> Is anybody here actually using a flyswatter2 debugger with a tegra3
> processor?

While my OpenOCD config files imply that I did try it on some Tegra30
device in the past, I haven't ever had much good luck with using it on
the main CPUs. I certainly have done some simple operations on the
AVP/boot processor, but not much worked on the A9s. This might be user
error, or might not; I'm not sure. This isn't an area I've put much time
into understanding.