[meta-zephyr][PATCH 5/5] zephyr-flash-pyocd.bbclass: support for flashing via pyocd

["Wojciech Zmuda" <zmuda.w@gmail.com>]

Flash boards supported via pyocd:

    MACHINE=xxx bitbake yyy -c flash_usb

The only supported board for now is 96Boards Nitrogen. Modify its
config accordingly.

Modify helloworld and philosopers samples with adidtional .hex
output file deployment, as this format is required by pyocd.

Describe the feature in README.

Signed-off-by: Wojciech Zmuda <wojciech.zmuda@huawei.com>
---
 README.txt                                    | 23 +++++++++++++++++++
 classes/zephyr-flash-pyocd.bbclass            | 17 ++++++++++++++
 conf/machine/96b-nitrogen.conf                |  1 +
 .../zephyr-kernel/zephyr-helloworld.bb        |  1 +
 .../zephyr-kernel/zephyr-philosophers.bb      |  1 +
 5 files changed, 43 insertions(+)
 create mode 100644 classes/zephyr-flash-pyocd.bbclass

diff --git a/README.txt b/README.txt
index 6463339..4366764 100644
--- a/README.txt
+++ b/README.txt
@@ -43,6 +43,29 @@ The same sample, for Nios2 image:
     $ MACHINE=qemu-nios2 bitbake zephyr-philosophers
     $ runqemu qemu-nios2
 
+Flashing
+=================================
+
+You can flash Zephyr samples to boards. Currently, the following MACHINEs
+are supported:
+ * DFU:
+  - arduino_101_sss
+  - arduino_101
+  - arduino_101_ble
+ * pyocd:
+  - 96b_nitrogen
+
+To flash the example you built with command e.g.
+
+    $ MACHINE=96b_nitrogen bitbake zephyr-philosophers
+
+call similar command with explicit flash_usb command:
+
+    $ MACHINE=96b_nitrogen bitbake zephyr-philosophers -c flash_usb
+
+dfu-util and/or pyocd need to be installed in your system. If you observe
+permission errors or the flashing process seem to hang, follow those instructions:
+https://github.com/pyocd/pyOCD/tree/master/udev
 
 Building and Running Zephyr Tests
 =================================
diff --git a/classes/zephyr-flash-pyocd.bbclass b/classes/zephyr-flash-pyocd.bbclass
new file mode 100644
index 0000000..aafe9e7
--- /dev/null
+++ b/classes/zephyr-flash-pyocd.bbclass
@@ -0,0 +1,17 @@
+
+python do_flash_usb() {
+    from pyocd.core.helpers import ConnectHelper
+    from pyocd.flash.file_programmer import FileProgrammer
+
+    image = f"{d.getVar('DEPLOY_DIR_IMAGE')}/{d.getVar('PN')}.hex"
+    bb.plain(f"Attempting to flash {image} to board {d.getVar('BOARD')}")
+
+    with ConnectHelper.session_with_chosen_probe() as session:
+        FileProgrammer(session).program(image)
+        session.board.target.reset()
+}
+
+addtask do_flash_usb
+
+do_flash_usb[nostamp] = "1"
+do_flash_usb[vardepsexclude] = "BB_ORIGENV"
diff --git a/conf/machine/96b-nitrogen.conf b/conf/machine/96b-nitrogen.conf
index d1905f2..998db4c 100644
--- a/conf/machine/96b-nitrogen.conf
+++ b/conf/machine/96b-nitrogen.conf
@@ -4,4 +4,5 @@
 #@DESCRIPTION: Machine configuration for 96Boards Nitrogen Board.
 
 require conf/machine/include/nrf52832.inc
+ZEPHYR_INHERIT_CLASSES += "zephyr-flash-pyocd"
 ARCH_96b-nitrogen = "arm"
diff --git a/recipes-kernel/zephyr-kernel/zephyr-helloworld.bb b/recipes-kernel/zephyr-kernel/zephyr-helloworld.bb
index 1400e72..9b77975 100644
--- a/recipes-kernel/zephyr-kernel/zephyr-helloworld.bb
+++ b/recipes-kernel/zephyr-kernel/zephyr-helloworld.bb
@@ -8,6 +8,7 @@ OECMAKE_SOURCEPATH = "${ZEPHYR_SRC_DIR}"
 
 do_deploy () {
     install -D ${B}/zephyr/${ZEPHYR_MAKE_OUTPUT}.elf ${DEPLOYDIR}/${PN}.elf
+    install -D ${B}/zephyr/${ZEPHYR_MAKE_OUTPUT}.hex ${DEPLOYDIR}/${PN}.hex
 }
 
 addtask deploy after do_compile
diff --git a/recipes-kernel/zephyr-kernel/zephyr-philosophers.bb b/recipes-kernel/zephyr-kernel/zephyr-philosophers.bb
index 5f7fbcb..f720999 100644
--- a/recipes-kernel/zephyr-kernel/zephyr-philosophers.bb
+++ b/recipes-kernel/zephyr-kernel/zephyr-philosophers.bb
@@ -8,6 +8,7 @@ OECMAKE_SOURCEPATH = "${ZEPHYR_SRC_DIR}"
 
 do_deploy () {
     install -D ${B}/zephyr/${ZEPHYR_MAKE_OUTPUT}.elf ${DEPLOYDIR}/${PN}.elf
+    install -D ${B}/zephyr/${ZEPHYR_MAKE_OUTPUT}.hex ${DEPLOYDIR}/${PN}.hex
 }
 
 addtask deploy after do_compile
-- 
2.25.1