Orchard gdb cheatsheet

If you're not familiar with gdb, here are some commands to get you started.

Starting GDB

To start GDB with Orchard, use these commands:

pi@raspberrypi ~/orchard-src/orchard $ gdb build/orchard.elf

Note that you're starting it in the same directory where you'd type make to build the executable.

Once GDB is started, you want to first execute

target remote localhost:3333

This establishes a connection between gdb and the orchard CPU.

Debugging with GDB

• To stop execution, hit ctrl-c. This will break you to a prompt.
• 'c' will continue execution
• 'mon reset' will reset the board
• 'b <function name>' will set a breakpoint at a given symbolic function name
• 'step' will step one source line, diving into functions
• 'next' will step one source line, treating functions as a single source line
• 'info reg' will give you the register dump
• 'info threads' will give you the status of all threads running on chibiOS
• 'bt' will give you the current backtrace
• 'l' will list the current source line that's running
• 'disas' will show you the assembly code of the current code that's running
• 'print <expression>' will print the value of a variable in the current stack frame

Also see http://darkdust.net/files/GDB%20Cheat%20Sheet.pdf

Layouts:

• to view assembly while single stepping "layout asm"
• to view registers, "layout reg"