Install OpenOCD

OpenOCD is a tool to connect with the target chip over JTAG and similar transports. It also provides a GDB server which is an “intermediate” when debugging software on the chip with GDB.

It is recommended to use the regular upstream version of OpenOCD instead of the RISC-V downstream fork.

It is trivial to install OpenOCD because we manage the dependency with Bazel. The Bazel-built OpenOCD binary lives at //third_party/openocd:openocd_bin. It’s not runnable, but we also provide a runnable wrapper: //third_party/openocd.

OpenOCD also ships with a library of config files. Instead of using use whichever config files happen to be installed on the system, prefer the Bazel-exposed config files that match OpenOCD source. Currently, we only expose OpenTitan’s default JTAG adapter config as //third_party/openocd:jtag_adapter_cfg.

# Manually run OpenOCD:
./ run //third_party/openocd -- arg1 arg2

# Get the path of the OpenOCD binary:
./ outquery //third_party/openocd:openocd_bin