Introduction

GDB can be used for debugging the code on the boards.

Procedure

Start openocd in a new shell since this process needs to remain running.
To program the Lisa/L board run the command
```
openocd -f interface/lisa-l.cfg -f board/lisa-l.cfg
```
Start GDB with an argument of the elf file created and uploaded to the board.
If you programmed with the ap target then the command would be along the lines of
```
arm-none-eabi-gdb var/<airframe>/ap/ap.elf
```
Replace <airframe> with the name of the airframe that has been built.
Now connect GDB to the board
```
target remote localhost:3333
```
Now we need to set some break points in the code.
In this example the ap target was part of the rotorcraft and main.c contains the main program. Open rotorcraft sw/airborne/firmwares/rotorcraft/main.c and find a line at which you'd like to set a break point.
```
break main.c:113
```
Stop the currently running code
```
monitor reset halt
```
Reset the code back to the start
```
monitor reset init
```
We probably want to ignore the interrupt calls for the moment so we can step through the code as it's being called. Note that we don't always want to do this.
```
monitor cortex_m3 maskisr on
```
Now we can run the program which will stop at the break point we set.
```
continue
```