boards: raspberrypi: rpi_pico2: Add OpenOCD runner configuration

Add OpenOCD debugger support.
For now we will need Raspberry Pi'a forked version of OpenOCD from
https://github.com/raspberrypi/openocd .

The default adapter speed is set to match Raspberry Pi's documentation.

Signed-off-by: Andrew Featherstone <[email protected]>

Author: ajf58

boards/raspberrypi/rpi_pico2/board.cmake

@@ -1,5 +1,18 @@
 # SPDX-License-Identifier: Apache-2.0
 
+if("${RPI_PICO_DEBUG_ADAPTER}" STREQUAL "")
+	set(RPI_PICO_DEBUG_ADAPTER "cmsis-dap")
+endif()
+
+board_runner_args(openocd --cmd-pre-init "source [find interface/${RPI_PICO_DEBUG_ADAPTER}.cfg]")
+board_runner_args(openocd --cmd-pre-init "source [find target/rp2350.cfg]")
+
+# The adapter speed is expected to be set by interface configuration.
+# The Raspberry Pi's OpenOCD fork doesn't, so match their documentation at
+# https://www.raspberrypi.com/documentation/microcontrollers/debug-probe.html#debugging-with-swd
+board_runner_args(openocd --cmd-pre-init "set_adapter_speed_if_not_set 5000")
+
 board_runner_args(uf2 "--board-id=RP2350")
 
-include(${ZEPHYR_BASE}/boards/common/uf2.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/uf2.board.cmake)

boards/raspberrypi/rpi_pico2/rpi_pico2_rp2350a_m33_defconfig

@@ -1,6 +1,7 @@
 # This configuration is orthogonal to whether the Cortex-M33 or Hazard3 cores
 # are in use, but Zephyr does not support providing a qualifier-agnostic
 # _defconfig file.
+CONFIG_BUILD_OUTPUT_HEX=y
 CONFIG_BUILD_OUTPUT_UF2=y
 CONFIG_CLOCK_CONTROL=y
 CONFIG_CONSOLE=y

boards/raspberrypi/rpi_pico2/support/openocd.cfg

@@ -0,0 +1,11 @@
+# Copyright (c) 2024 TOKITA Hiroshi
+# SPDX-License-Identifier: Apache-2.0
+
+# Checking and set 'adapter speed'.
+# Set the adaptor speed, if unset, and given as an argument.
+proc set_adapter_speed_if_not_set { speed } {
+	puts "checking adapter speed..."
+	if { [catch {adapter speed} ret] } {
+		adapter speed $speed
+	}
+}