board: arm: nucleo_g071 support openocd

This adds the support of openocd for nucleo board stm32g071rb
It requires the openocd that supports stm32G0xx
(zephyrproject-rtos/openocd#24)

Signed-off-by: Francois Ramu <francois.ramu@st.com>

boards/arm/nucleo_g071rb/board.cmake

@@ -4,3 +4,4 @@ board_runner_args(pyocd "--flash-opt=-O reset_type=hw")
 board_runner_args(pyocd "--flash-opt=-O connect_mode=under-reset")
 
 include(${ZEPHYR_BASE}/boards/common/pyocd.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)

boards/arm/nucleo_g071rb/doc/index.rst

@@ -133,7 +133,9 @@ Flashing
 ========
 
 Nucleo G071RB board includes an ST-LINK/V2-1 embedded debug tool interface.
+
 This interface is not yet supported by the openocd version included in the Zephyr SDK.
+
 Instead, support can be enabled on pyocd by adding "pack" support with
 the following pyocd command:
 
@@ -141,6 +143,16 @@ the following pyocd command:
 
    $ pyocd pack --install stm32g071rb
 
+Note:
+To manually enable the openocd interface, You can still update, compile and install
+a 'local' openocd from the official openocd repo http://openocd.zylin.com .
+Then run the following openocd command where the '/usr/local/bin/openocd'is your path
+for the freshly installed openocd, given by "$ which openocd" :
+
+.. code-block:: console
+
+   $ west flash --openocd /usr/local/bin/openocd
+
 Flashing an application to Nucleo G071RB
 ----------------------------------------
 

boards/arm/nucleo_g071rb/support/openocd.cfg

@@ -0,0 +1,7 @@
+source [find interface/stlink.cfg]
+
+transport select hla_swd
+
+source [find target/stm32g0x.cfg]
+
+reset_config srst_only