SparkFun Electronics Forum

Hi,
This is my first question here. I am trying to learn OpenOCD. And sorry for asking a dump questions.
My Questions are:
1) OCD = On Chip Debugger => How is it OnCHIP ?? isn't Onchip is something which exists right there on Silicon?
2) Debugger = How is it a debugger. i means its job is just to interpret Interface (jtag, swi, icdi etc) signals and to connect with it? and even if it is a debugger, why then we need GDB with OpenOCD to debug code?
3) Hows is it different from let say JTAG device driver? i mean JTAG driver also enables you to communicate with external connected device chip?

1) the capability is either available on your particular chip or it's not.

Many of your questions are answered on this site:
https://hackaday.com/2012/09/27/beginne ... debugging/

Thanks for your reply. The link indeed presents pretty much good info but still i have the same confusion. Can you please answer in bulleted form one per question. I am still confused why GDB is required, can't we just send commands directly to openOCD?

Kowalski wrote: ↑Fri Nov 03, 2017 11:44 pm 1) OCD = On Chip Debugger => How is it OnCHIP ?? isn't Onchip is something which exists right there on Silicon?

It's the on-chip capability that's on the silicon - On Chip Debugging.

Kowalski wrote: ↑Fri Nov 03, 2017 11:44 pm2) Debugger = How is it a debugger. i means its job is just to interpret Interface (jtag, swi, icdi etc) signals and to connect with it? and even if it is a debugger, why then we need GDB with OpenOCD to debug code?

from the link:
In order to do this type of debugging you need three things: a program that controls the chip’s debugging mode (OPENOCD), a way to interface with it (GDB), and a program which has been compiled with debugging information (use -g option to include debugging information).

Kowalski wrote: ↑Fri Nov 03, 2017 11:44 pm3) Hows is it different from let say JTAG device driver? i mean JTAG driver also enables you to communicate with external connected device chip?

I don't know - I believe JTAG is a hardware interface.

This whole question is like asking why you need a pre-processor, a compiler, and a linker to build a program. You kind of need this stuff to do a proper job.