Embdebug is the generic GDB/LLDB debug server for embedded systems. This is the target specific library for embedded CORE-V targets.

These instructions only focus on building the target standalone. However the more usual way to build the target is by being symbolically linked into the Embdebug source tree, and being built together with Embdebug. This is documented as part of the Embdebug repository.

Check out core-v-mcu and switch to its top level directory. Build the model library

make model-lib

Note. You need to have FuseSoc and Verilator (4.20 or greater) installed.

Make a note of the directory holding the generated model, which will be something like.

build/openhwgroup.org_systems_core-v-mcu_0/model-lib-sim-verilator/obj_dir

Created a build directory, we'll assume at the top level

mkdir bd

Configure with CMake, specifying the location of the Embedebug include directory and the Verilator model directory. You may need to change the precise details depending on your directory hierarchy.

cmake -DCMAKE_INSTALL_PREFIX=<install-dir> \
    -DEMBDEBUG_INCLUDE_DIR=<embdebug-dir>/include \
    -DCV_MCU_BUILD_DIR=<model-dir>

• <install-dir> is the directory where you want the generated library stored (optional).
• <embdebug-dir> is the root directory of the generic Embddebug engine.
• <model-dir> is the location of the generated MCU verilator model. Typically something like build/openhwgroup.org_systems_core-v-mcu_0/model-lib-verilator/obj_dir within the core-v-mcu repository.

Build and install using CMake

cmake --build . -- -j $(nproc)
cmake --build . --target install

(Only install if you have specified -DCMAKE_INSTALL_PREFIX).

The CORE-V MCU code initializes its boot ROM by using $readmemh with a relative file name. This means you need the mem_init directory to be in the same directory from which you run Embdebug. A workaround to make Embdebug more usable is to edit the CORE-V MCU code to use an absolute file name witnin $readmemh.

Once built and installed, you can start the server using

embdebug --soname cv32e40

This will start the server, with the CV32E40P model and report a port name on which to connect. Use embdebug --help to see other options which are accessible. You can then connect from RISC-V GDB using:

(gdb) target remote :<pornum>

Where <portnum> is the port number reported when starting Embdebug.

It is also possible to start embdebug directly from within gdb and connect via a pipe. In this case there is no need to run Embdebug itself. From within GDB, you can just use

(gdb) target remote | embdebug --soname cv32e40
```