scripts: Add flash and debug support using pyOCD on NXP boards

Adds a new debug support script using pyOCD and configures most NXP
boards so they can use it. frdm_kw41z is the one exception because pyOCD
doesn't yet support kw41z. Tested with pyOCD v0.8.0 and the latest
DAPLink firmware for each board.

Introduces two new environment variables, PYOCD_FLASHTOOL and
PYOCD_GDBSERVER, that allow you to set custom paths to the pyOCD tools.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>

boards/arm/frdm_k64f/Makefile.board

@@ -6,4 +6,6 @@ OPENOCD_VERIFY_CMD = "verify_image ${O}/${KERNEL_BIN_NAME} ${CONFIG_FLASH_BASE_A
 
 JLINK_DEVICE = MK64FN1M0xxx12
 
-export FLASH_SCRIPT OPENOCD_LOAD_CMD OPENOCD_VERIFY_CMD JLINK_DEVICE
+PYOCD_TARGET = k64f
+
+export FLASH_SCRIPT OPENOCD_LOAD_CMD OPENOCD_VERIFY_CMD JLINK_DEVICE PYOCD_TARGET

boards/arm/frdm_kl25z/Makefile.board

@@ -2,4 +2,6 @@ DEBUG_SCRIPT = jlink.sh
 
 JLINK_DEVICE = MKL25Z128xxx4
 
-export JLINK_DEVICE
+PYOCD_TARGET = kl25z
+
+export JLINK_DEVICE PYOCD_TARGET

boards/arm/hexiwear_k64/Makefile.board

@@ -2,4 +2,6 @@ DEBUG_SCRIPT = jlink.sh
 
 JLINK_DEVICE = MK64FN1M0xxx12
 
-export JLINK_DEVICE
+PYOCD_TARGET = k64f
+
+export JLINK_DEVICE PYOCD_TARGET

boards/arm/hexiwear_kw40z/Makefile.board

@@ -2,4 +2,6 @@ DEBUG_SCRIPT = jlink.sh
 
 JLINK_DEVICE = MKW40Z160xxx4
 
-export JLINK_DEVICE
+PYOCD_TARGET = kw40z4
+
+export JLINK_DEVICE PYOCD_TARGET

scripts/support/pyocd.sh

@@ -0,0 +1,78 @@
+#!/bin/sh
+
+# This script is loosly based on a script with same purpose provided
+# by RIOT-OS (https://github.com/RIOT-OS/RIOT)
+
+PYOCD_FLASHTOOL=${PYOCD_FLASHTOOL:-pyocd-flashtool}
+PYOCD_GDBSERVER=${PYOCD_GDBSERVER:-pyocd-gdbserver}
+BIN_NAME=${O}/${KERNEL_BIN_NAME}
+ELF_NAME=${O}/${KERNEL_ELF_NAME}
+GDB_PORT=${GDB_PORT:-3333}
+
+test_config() {
+    if ! which ${PYOCD_FLASHTOOL} >/dev/null 2>&1; then
+        echo "Error: Unable to locate pyOCD flash tool: ${PYOCD_FLASHTOOL}"
+        exit 1
+    fi
+    if ! which ${PYOCD_GDBSERVER} >/dev/null 2>&1; then
+        echo "Error: Unable to locate pyOCD GDB server: ${PYOCD_GDBSERVER}"
+        exit 1
+    fi
+}
+
+test_bin() {
+    if [ ! -f "${BIN_NAME}" ]; then
+        echo "Error: Unable to locate image binary: ${BIN_NAME}"
+        exit 1
+    fi
+}
+
+do_flash() {
+    test_config
+    test_bin
+
+    # flash device with specified image
+    echo "Flashing Target Device"
+    ${PYOCD_FLASHTOOL} -t ${PYOCD_TARGET} ${BIN_NAME}
+}
+
+
+do_debug() {
+    do_debugserver 1 &
+
+    # connect to the GDB server
+    ${GDB} ${TUI} ${ELF_NAME} \
+	-ex "target remote :${GDB_PORT}" \
+	-ex 'load' \
+	-ex 'monitor reset halt'
+}
+
+do_debugserver() {
+    test_config
+
+    # Calling with an arg will result in setsid being used, which will prevent
+    # Ctrl-C in GDB from killing the server. The server automatically exits
+    # when the remote GDB disconnects.
+    if [ -n "$1" ]; then
+        SETSID=/usr/bin/setsid
+    else
+        SETSID=
+    fi
+    echo "pyOCD GDB server running on port ${GDB_PORT}"
+    ${SETSID} ${PYOCD_GDBSERVER} -p ${GDB_PORT} -t ${PYOCD_TARGET}
+}
+
+CMD="$1"
+shift
+
+case "${CMD}" in
+  flash)
+    do_flash "$@"
+    ;;
+  debugserver)
+    do_debugserver "$@"
+    ;;
+  debug)
+    do_debug "$@"
+    ;;
+esac