From 15b16695c673426e334777e7d794794862ab914a Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Tue, 4 Sep 2018 19:04:27 +0800
Subject: [PATCH] frontend: add artiq_route

---
 artiq/frontend/artiq_route.py | 83 +++++++++++++++++++++++++++++++++++
 setup.py                      |  1 +
 2 files changed, 84 insertions(+)
 create mode 100755 artiq/frontend/artiq_route.py

diff --git a/artiq/frontend/artiq_route.py b/artiq/frontend/artiq_route.py
new file mode 100755
index 000000000..c818237ce
--- /dev/null
+++ b/artiq/frontend/artiq_route.py
@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+
+import argparse
+
+
+def get_argparser():
+    parser = argparse.ArgumentParser(description="ARTIQ DRTIO routing table "
+                                                 "manipulation tool")
+
+    parser.add_argument("file", metavar="FILE", type=str,
+                        help="target file")
+
+    action = parser.add_subparsers(dest="action")
+    action.required = True
+
+    action.add_parser("init", help="create a new empty routing table")
+    
+    action.add_parser("show", help="show contents of routing table")
+
+    a_set = action.add_parser("set", help="set routing table entry")
+    a_set.add_argument("destination", metavar="DESTINATION", type=int,
+                       help="destination to operate on")
+    a_set.add_argument("hop", metavar="HOP", type=int, nargs="*",
+                       help="hop(s) to the destination")
+
+    return parser
+
+
+ENTRY_COUNT = 256
+MAX_HOPS = 32
+
+
+def init(filename):
+    with open(filename, "wb") as f:
+        f.write(b"\xff"*(ENTRY_COUNT*MAX_HOPS))
+
+
+def show_routes(filename):
+    routes = []
+    with open(filename, "rb") as f:
+        for i in range(ENTRY_COUNT):
+            hops = [int.from_bytes(f.read(1), "big") for j in range(MAX_HOPS)]
+            routes.append(hops)
+
+    for destination, route in enumerate(routes):
+        if route[0] != 0xff:
+            fmt = "{:3d}:".format(destination)
+            for hop in route:
+                if hop == 0xff:
+                    break
+                fmt += " {:3d}".format(hop)
+            print(fmt)
+
+
+def set_route(filename, destination, hops):
+    with open(filename, "r+b") as f:
+        if destination >= ENTRY_COUNT:
+            raise ValueError("destination must be less than {}".format(ENTRY_COUNT))
+        f.seek(destination*MAX_HOPS)
+
+        if len(hops) + 1 >= MAX_HOPS:
+            raise ValueError("too many hops")
+        for hop in hops:
+            if hop >= 0xff:
+                raise ValueError("all hops must be less than 255")
+
+        hops = hops + [0xff]*(MAX_HOPS-len(hops))
+        f.write(bytes(hops))
+
+
+def main():
+    args = get_argparser().parse_args()
+    if args.action == "init":
+        init(args.file)
+    elif args.action == "show":
+        show_routes(args.file)
+    elif args.action == "set":
+        set_route(args.file, args.destination, args.hop)
+    else:
+        raise ValueError
+
+if __name__ == "__main__":
+    main()
diff --git a/setup.py b/setup.py
index a85f23ae5..b4c25b027 100755
--- a/setup.py
+++ b/setup.py
@@ -30,6 +30,7 @@ console_scripts = [
     "artiq_master = artiq.frontend.artiq_master:main",
     "artiq_mkfs = artiq.frontend.artiq_mkfs:main",
     "artiq_session = artiq.frontend.artiq_session:main",
+    "artiq_route = artiq.frontend.artiq_route:main",
     "artiq_rpctool = artiq.frontend.artiq_rpctool:main",
     "artiq_run = artiq.frontend.artiq_run:main",
     "artiq_flash = artiq.frontend.artiq_flash:main",