Awesome

N64 GDB Stub

This is a gdb stub for the n64 that works with a modified version of cen64. In order to properly use this stub you need to use the fork of cen64 here. This stub currently depends on libdragon.

You'll need to add the gdbstub.c and gdbstub_sys.c files to your project. If you execute the makefile contained in this repo, it will build an example program using this stub.

When you start the cen64 emulator it will wait for a connection from gdbserver over a tcp socket. The emulator will create a tcp socket on port 2159. When running gdb (built for mips64-elf) you can then execute the gdb command target remote localhost:2159 to connect.

How to use the example project

This section assumes that you have already built the modified cen64 and a version of gdb for mips64-elf. In order to build this rom you first need to set the environment variable N64_INST to the path where you n64 toolchain is installed. Once that is done you can run the command make to build the example rom which will be called out.z64. To debug this rom you need to open cen64 with this rom. The emulator window will not open until the debugger is connected. To connect the debug run mips64-elf-gdb out.elf (note that we use the elf file here and not the n64 rom, this is required to get the right debug symbols). Once gdb has opened you will need to type in target remote 2159 (this step assumed that you have ran gdb from the same folder cen64 was run from). The debugger will then connect and you will be able to use gdb commands to set breakpoints and inspect the target.

How to use this stub

To use this stub you simply need to include the source files (gdbstub.c & gdbstub_sys.c) into your project. After they are included you need to add a call to dbg_main() in your program near initilization to connect the debugger.

TODO

[ ] Implement stepping support. Currently only continue is supported. Cannot step lines of source code on the target [x] Use generic socket interface so library will work on more operating systems