To build:

```shell
bazelisk build //hello_xtensa --platforms=//hello_xtensa:qemu_xtensa_dc233c
```

Then to run:

```
qemu-system-xtensa -nographic -machine virt -cpu dc233c -semihosting -kernel bazel-bin/hello_xtensa/hello_xtensa
```

Use Ctrl-A + X to exit from QEMU.

qemu-system-xtensa can be downloaded as part of the "hosttools" package from the Zephyr SDK:
https://github.com/zephyrproject-rtos/sdk-ng/releases.