boards: mec172xevb_assy6906: support remote flashing

This allows mec172xevb_assy6906 to support misc-flasher to run
arbitrary script to flash the SPI chip. A script is also
provided as an example.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>

Author: dcpleung

boards/arm/mec172xevb_assy6906/board.cmake

@@ -9,3 +9,6 @@ board_finalize_runner_args(dediprog
   "--spi-image=${PROJECT_BINARY_DIR}/${SPI_IMAGE_NAME}"
   "--vcc=0"
 )
+
+# This allows a custom script to be used for flashing the SPI chip.
+include(${ZEPHYR_BASE}/boards/common/misc.board.cmake)

boards/arm/mec172xevb_assy6906/support/mec172x_remote_flasher.py

@@ -0,0 +1,180 @@
+#!/usr/bin/env python3
+#
+# Copyright (c) 2023 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+'''
+This script allows flashing a mec172xevb_assy6906 board
+attached to a remote system.
+
+Usage:
+  west flash -r misc-flasher -- mec172x_remote_flasher.py <remote host>
+
+Note:
+1. SSH access to remote host with write access to remote /tmp.
+   Since the script does multiple SSH connections, it is a good idea
+   to setup public key authentication and ssh-agent.
+2. Dediprog "dpcmd" available in path on remote host.
+   (Can be compiled from https://github.com/DediProgSW/SF100Linux)
+3. SSH user must have permission to access USB devices,
+   since dpcmd needs USB access to communicate with
+   the Dediprog programmer attached to remote host.
+
+To use with twister, a hardware map file is needed.
+Here is a sample map file:
+
+  - connected: true
+    available: true
+    id: mec172xevb_assy6906
+    platform: mec172xevb_assy6906
+    product: mec172xevb_assy6906
+    runner: misc-flasher
+    runner_params:
+      - <ZEPHYR_BASE>/boards/arm/mec172xevb_assy6906/support/mec172x_remote_flasher.py
+      - <remote host>
+    serial_pty: "nc,<remote host>,<ser2net port>"
+
+The sample map file assumes the serial console is exposed via ser2net,
+and that it can be accessed using nc (netcat).
+
+To use twister:
+  ./scripts/twister --hardware-map <hw map file> --device-testing
+
+Required:
+* Fabric (https://www.fabfile.org/)
+'''
+
+import argparse
+import hashlib
+import pathlib
+import sys
+
+from datetime import datetime
+
+import fabric
+from invoke.exceptions import UnexpectedExit
+
+def calc_sha256(spi_file):
+    '''
+    Calculate a SHA256 of the SPI binary content plus current
+    date string.
+
+    This is used for remote file name to avoid file name
+    collision.
+    '''
+    sha256 = hashlib.sha256()
+
+    # Use SPI file content to calculate SHA.
+    with open(spi_file, "rb") as fbin:
+        spi_data = fbin.read()
+        sha256.update(spi_data)
+
+    # Add a date/time to SHA to hopefully
+    # further avoid file name collision.
+    now = datetime.now().isoformat()
+    sha256.update(now.encode("utf-8"))
+
+    return sha256.hexdigest()
+
+def parse_args():
+    '''
+    Parse command line arguments.
+    '''
+    parser = argparse.ArgumentParser(allow_abbrev=False)
+
+    # Fixed arguments
+    parser.add_argument("build_dir",
+                        help="Build directory")
+    parser.add_argument("remote_host",
+                        help="Remote host name or IP address")
+
+    # Arguments about remote machine
+    remote = parser.add_argument_group("Remote Machine")
+    remote.add_argument("--remote-tmp", required=False,
+                        help="Remote temporary directory to store SPI binary "
+                             "[default=/tmp for Linux remote]")
+    remote.add_argument("--dpcmd", required=False, default="dpcmd",
+                        help="Full path to dpcmd on remote machine")
+
+    # Remote machine type.
+    # This affects how remote path is constructed.
+    remote_type = remote.add_mutually_exclusive_group()
+    remote_type.add_argument("--remote-is-linux", required=False,
+                             default=True, action="store_true",
+                             help="Set if remote machine is a Linux-like machine [default]")
+    remote_type.add_argument("--remote-is-win", required=False,
+                             action="store_true",
+                             help="Set if remote machine is a Windows machine")
+
+    return parser.parse_args()
+
+def main():
+    '''
+    Main
+    '''
+    args = parse_args()
+
+    # Check for valid arguments and setup variables.
+    if not args.remote_tmp:
+        if args.remote_is_win:
+            # Do not assume a default temporary on Windows,
+            # as it is usually under user's directory and
+            # we do not know enough to construct a valid path
+            # at this time.
+            print("[ERROR] --remote-tmp is required for --remote-is-win")
+            sys.exit(1)
+
+        if args.remote_is_linux:
+            remote_tmp = pathlib.PurePosixPath("/tmp")
+    else:
+        if args.remote_is_win:
+            remote_tmp = pathlib.PureWindowsPath(args.remote_tmp)
+        elif args.remote_is_linux:
+            remote_tmp = pathlib.PurePosixPath(args.remote_tmp)
+
+    # Construct full path to SPI binary.
+    spi_file_path = pathlib.Path(args.build_dir)
+    spi_file_path = spi_file_path.joinpath("zephyr", "spi_image.bin")
+
+    # Calculate a sha256 digest for SPI file.
+    # This is used for remote file to avoid file name collision
+    # if there are multiple MEC17x attached to remote machine
+    # and all are trying to flash at same time.
+    sha256 = calc_sha256(spi_file_path)
+
+    # Construct full path on remote to store
+    # the transferred SPI binary.
+    remote_file_name = remote_tmp.joinpath(f"mec172x_{sha256}.bin")
+
+    print(f"[INFO] Build directory: {args.build_dir}")
+    print(f"[INFO] Remote host: {args.remote_host}")
+
+    # Connect to remote host via SSH.
+    ssh = fabric.Connection(args.remote_host, forward_agent=True)
+
+    print("[INFO] Sending file...")
+    print(f"[INFO]   Local SPI file: {spi_file_path}")
+    print(f"[INFO]   Remote SPI file: {remote_file_name}")
+
+    # Open SFTP channel, and send the SPI binary over.
+    sftp = ssh.sftp()
+    sftp.put(str(spi_file_path), str(remote_file_name))
+
+    # Run dpcmd to flash the device.
+    try:
+        dpcmd_cmd = f"{args.dpcmd} --auto {str(remote_file_name)} --verify"
+        print(f"[INFO] Invoking: {dpcmd_cmd}...")
+        ssh.run(dpcmd_cmd)
+    except UnexpectedExit:
+        print("[ERR ] Cannot flashing SPI binary!")
+
+    # Remove temporary file.
+    print(f"[INFO] Removing remote file {remote_file_name}")
+    sftp.remove(str(remote_file_name))
+
+    sftp.close()
+    ssh.close()
+
+if __name__ == "__main__":
+    main()