Flyswatter2 Beagleboard XM How To
- 1 Connecting the Flyswatter2 and the Beagleboard XM
- 1.1 Set the EMU pins on the JTAG Adapter Board.
- 1.2 Connect the JTAG Adapter Board to the Flyswatter2.
- 1.3 Connect the 14-pin Ribbon Cable to the JTAG Adapter Board.
- 1.4 Connect the 10-pin Ribbon Cable to the RS-232 Adapter Board.
- 1.5 Connect the Other End of the Ribbon Cable to the Beagleboard XM.
- 1.6 Plug in the Serial Cable.
- 1.7 Connect the USB cable to the Flyswatter2.
- 1.8 Connect the Power Cable to the Beagleboard XM.
- 1.9 Plug the Power Adapter into a Wall Outlet.
- 1.10 Plug the USB Cable into your PC.
- 2 Installing OpenOCD
- 3 Running OpenOCD
- 4 Common OpenOCD Commands
- 5 GDB Debugger
Connecting the Flyswatter2 and the Beagleboard XM
To hook up the Flyswatter2 and the Beagleboard XM, you will need:
- 20-pin ARM to 14-pin TI JTAG Adapter Board
- 14-pin JTAG Ribbon Cable
- RS-232 Serial Cable with one male, one female head
- USB Male A/Male B Cable
- 5V1A Power Cable
Set the EMU pins on the JTAG Adapter Board.
Connect the JTAG Adapter Board to the Flyswatter2.
Connect the 14-pin Ribbon Cable to the JTAG Adapter Board.
Connect the 10-pin Ribbon Cable to the RS-232 Adapter Board.
Connect the Other End of the Ribbon Cable to the Beagleboard XM.
Plug in the Serial Cable.
Connect the USB cable to the Flyswatter2.
Connect the Power Cable to the Beagleboard XM.
Plug the Power Adapter into a Wall Outlet.
The green power LED on the Beagleboard XM should come on and remain on.
Plug the USB Cable into your PC.
The green power LED on the Flyswatter2 should come on and remain on.
OpenOCD (Open On-Chip Debugger) is open-source software that interfaces with the Flyswatter2. OpenOCD provides debugging and in-system programming for embedded target devices. You will need to compile OpenOCD from source, and patch the source with one of the OpenOCD Patches for Flyswatter 2 support.
Whichever guide you use, be sure to install the patch! Both guides include instructions on downloading and installing the patch.
Compiling OpenOCD Linux - This set of instructions uses libFTDI, an open-source driver library for FTDI devices.
Now you are ready to run OpenOCD. If you installed the OpenOCD Ubuntu package, open a terminal window and type the following from any directory:
openocd -f interface/flyswatter2.cfg -f board/ti_beagleboard_xm.cfg -c init -c "reset init"
If you compiled OpenOCD yourself, navigate to the openocd-bin directory you created in the compile guide and type:
cd ~/openocd-bin sudo ./openocd -f interface/flyswatter2.cfg -f board/ti_beagleboard_xm.cfg -c init -c "reset init"
For more information, see Running OpenOCD on Linux. When you start OpenOCD, its output should look like this:
JTAG-DP_STICKY_ERROR on startup
You may see one or more JTAG-DP_STICKY_ERROR immediately on startup. This is caused by a bug in OpenOCD, but don't worry. OpenOCD will still be able to communicate with the board. The errors look like this.
The -c init -c "reset init" commands at the end of the OpenOCD startup is a workaround for this error. If you don't include the init and reset init commands, you will still be able to use OpenOCD with the Beagleboard XM. However, if you exit and restart OpenOCD, it will fail to connect unless you unplug the Flyswatter and plug it back in.
You cannot enter commands directly to OpenOCD. Open a new terminal window and type:
telnet localhost 4444
You will should see this prompt:
You can give commands to OpenOCD through this prompt.
Common OpenOCD Commands
To see a full list of OpenOCD commands, enter help in the telnet window.
Resets the Beagleboard XM. The output of the Reset command should look like this:
Sends a halt request to the Beagleboard XM. If the Beagleboard XM halts, you will see text output in the telnet window. (If the Beagleboard XM is already halted, you will see no output.)
You can also use halt followed by a time in milliseconds. OpenOCD waits for the target to halt the specified amount of time, then gives up if the target has not halted. You can use this to avoid OpenOCD hanging because the Beagleboard XM fails to halt. For example, to send a halt command with a timeout of one second, type:
Enter resume to end a halt. You will not see any text output in the telnet window.
Displays a numbered list of all of the Beagleboard XM's registers.
Run reg with a register number to display the contents of a register, in hexadecimal. The register number corresponds to the output of the reg command with no arguments, above. You must run the halt command before reading registers.
If you run reg while the Beagleboard XM is not halted, you will still see the value stored in the register. However, registers change contents very quickly while the device is running; by the time you see the value, the value actually in the register may be different. If you try to run reg while the device is not halted, you will see this:
reg [entry] [value]
Sets the value of a register. The register number corresponds to the output of the reg command with no arguments, above. Make sure the Beagleboard XM is halted (with the halt command) before you change the value of a register!
You can enter registry values in either decimal, by typing a number by itself, or in hexadecimal, by prefacing the value with 0x.
GDB, the GNU Project Debugger is a debugging tool provided with the GNU Compiler Collection (GCC). GDB allows you to stop and start a running program, examine its functioning, and make changes. GDB is installed on Ubuntu 10.04 by default, but you will need a different version of GDB build for embedded targets. Follow the instructions on the GDB Debugger page below.
The GDB debugger page will walk you through installing GDB for use with OpenOCD, and loading and testing a simple program.