rp2040: Add a bazel rule for flashing

Change-Id: I13baea1b64e3b2488dcba78fc05d9df0264b1300
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/216314
Pigweed-Auto-Submit: Aaron Green <[email protected]>
Commit-Queue: Aaron Green <[email protected]>
Reviewed-by: Armando Montanez <[email protected]>
Lint: Lint 🤖 <[email protected]>

pw_system/BUILD.bazel

@@ -19,6 +19,7 @@ load(
 )
 load("//pw_system/py:console.bzl", "device_console", "device_simulator_console")
 load("//targets/host_device_simulator:transition.bzl", "host_device_simulator_binary")
+load("//targets/rp2040:flash.bzl", "flash_rp2040")
 load("//targets/rp2040:transition.bzl", "rp2040_binary")
 
 package(default_visibility = ["//visibility:public"])
@@ -438,6 +439,12 @@ rp2040_binary(
     binary = ":system_example",
 )
 
+flash_rp2040(
+    name = "flash_rp2040_system_example",
+    testonly = True,
+    rp2040_binary = ":rp2040_system_example",
+)
+
 # Start :simulator_system_example and connect to it with pw console.
 device_simulator_console(
     name = "simulator_system_example_console",

targets/rp2040/flash.bzl

@@ -0,0 +1,40 @@
+# Copyright 2024 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+"""Bazel macros for flashing an rp2040 binary."""
+
+load("@bazel_skylib//rules:native_binary.bzl", "native_binary")
+
+def flash_rp2040(
+        name,
+        rp2040_binary,
+        **kwargs):
+    """Flash the binary to a connected rp2040 device.
+
+    Args:
+      name: The name of this flash_rp2040 rule.
+      rp2040_binary: The binary target to flash.
+      **kwargs: Forwarded to the underlying native_binary rule.
+    """
+    data = [rp2040_binary]
+    args = ["$(rootpath " + rp2040_binary + ")"]
+
+    native_binary(
+        name = name,
+        src = "@pigweed//targets/rp2040/py:flash",
+        args = args,
+        data = data,
+        # Note: out is mandatory in older bazel-skylib versions.
+        out = name + ".exe",
+        **kwargs
+    )