From 79996281be90c3969f24b6b2683358a8a6bd00d0 Mon Sep 17 00:00:00 2001
From: Ryan Slawson <ryan@qbaylogic.com>
Date: Wed, 19 Feb 2025 12:04:17 +0100
Subject: [PATCH] Make GDB init wait until target device is connected.

---
 .../src/Bittide/Instances/Hitl/Driver/Demo.hs       | 13 +++----------
 .../src/Bittide/Instances/Hitl/Utils/Program.hs     |  7 ++++++-
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/bittide-instances/src/Bittide/Instances/Hitl/Driver/Demo.hs b/bittide-instances/src/Bittide/Instances/Hitl/Driver/Demo.hs
index 7cd899785..0cf42865d 100644
--- a/bittide-instances/src/Bittide/Instances/Hitl/Driver/Demo.hs
+++ b/bittide-instances/src/Bittide/Instances/Hitl/Driver/Demo.hs
@@ -15,7 +15,6 @@ import Bittide.Instances.Hitl.Setup (demoRigInfo)
 import Bittide.Instances.Hitl.Utils.Program
 import Bittide.Instances.Hitl.Utils.Vivado
 
-import Control.Exception (SomeException, catch)
 import Control.Monad (forM_, zipWithM)
 import Control.Monad.IO.Class
 import Data.Maybe (fromMaybe)
@@ -182,6 +181,9 @@ driverFunc testName targets = do
         </> "gdb-" <> binName <> "-" <> show (getTargetIndex hwT) <> ".log"
       Gdb.setFile gdb $ firmwareBinariesDir "riscv32imc" Release </> binName
       Gdb.setTarget gdb gdbPort
+      Gdb.runCommands gdb.stdinHandle ["echo connected to target device"]
+      tryWithTimeout "Waiting for GDB to be ready to proceed" 15_000_000
+        $ expectLine gdb.stdoutHandle gdbWaitForConnect
 
       let
         gdbProcName = "GDB (" <> binName <> ", " <> show d.deviceId <> ")"
@@ -246,16 +248,8 @@ driverFunc testName targets = do
           then (count + 1, acc)
           else (count, code)
 
-    dumpBuffer :: Handle -> (Handle -> IO a) -> IO ()
-    dumpBuffer hdl f = do
-      ready <- catch (hReady hdl) $ \(_ :: SomeException) -> return False
-      if ready
-        then f hdl >> dumpBuffer hdl f
-        else return ()
-
     muGdbCheck :: (HwTarget, DeviceInfo) -> ProcessStdIoHandles -> VivadoM ExitCode
     muGdbCheck (_, _) gdb = do
-      liftIO $ dumpBuffer gdb.stdoutHandle hGetLine
       liftIO $ Gdb.runCommands gdb.stdinHandle ["x/4sb 0x60000000", "echo END OF WHOAMI\\n"]
       gdbRead <-
         liftIO
@@ -266,7 +260,6 @@ driverFunc testName targets = do
 
     ccGdbCheck :: (HwTarget, DeviceInfo) -> ProcessStdIoHandles -> VivadoM ExitCode
     ccGdbCheck (_, _) gdb = do
-      liftIO $ dumpBuffer gdb.stdoutHandle hGetLine
       liftIO $ Gdb.runCommands gdb.stdinHandle ["x/4sb 0x60000000", "echo END OF WHOAMI\\n"]
       gdbRead <-
         liftIO
diff --git a/bittide-instances/src/Bittide/Instances/Hitl/Utils/Program.hs b/bittide-instances/src/Bittide/Instances/Hitl/Utils/Program.hs
index 615ddfc58..e1bb139bf 100644
--- a/bittide-instances/src/Bittide/Instances/Hitl/Utils/Program.hs
+++ b/bittide-instances/src/Bittide/Instances/Hitl/Utils/Program.hs
@@ -14,7 +14,7 @@ import Paths_bittide_instances
 
 import Control.Monad.Catch
 import Control.Monad.IO.Class
-import Data.List (isPrefixOf)
+import Data.List (isInfixOf, isPrefixOf)
 import Data.Maybe (fromJust)
 import System.IO
 import System.Posix.Env (getEnvironment)
@@ -239,6 +239,11 @@ openOcdWaitForHalt s
   | "Halting processor" `isPrefixOf` s = Stop Ok
   | otherwise = Continue
 
+gdbWaitForConnect :: String -> Filter
+gdbWaitForConnect s
+  | "connected to target device" `isInfixOf` s = Stop Ok
+  | otherwise = Continue
+
 gdbWaitForLoad :: String -> Filter
 gdbWaitForLoad s
   | "Remote communication error." `isPrefixOf` s =