Reintroduce debug plugin (instruction injector need optimisations)

src/main/scala/vexriscv/Services.scala

@@ -14,6 +14,7 @@ trait JumpService{
 trait IBusFetcher{
   def haltIt() : Unit
   def nextPc() : (Bool, UInt)
+  def getInjectionPort() : Stream[Bits]
 }
 
 

src/main/scala/vexriscv/TestsWorkspace.scala

@@ -35,28 +35,28 @@ object TestsWorkspace {
 //            resetVector = 0x80000000l,
 //            relaxedPcCalculation = false
 //          ),
-//          new IBusSimplePlugin(
-//            interfaceKeepData = false,
-//            catchAccessFault = true
-//          ),
-          new IBusCachedPlugin(
-            config = InstructionCacheConfig(
-              cacheSize = 1024*16,
-              bytePerLine = 32,
-              wayCount = 1,
-              addressWidth = 32,
-              cpuDataWidth = 32,
-              memDataWidth = 32,
-              catchIllegalAccess = false,
-              catchAccessFault = true,
-              catchMemoryTranslationMiss = false,
-              asyncTagMemory = false,
-              twoCycleRam = false
-            )//,
+          new IBusSimplePlugin(
+            interfaceKeepData = false,
+            catchAccessFault = true
+          ),
+//          new IBusCachedPlugin(
+//            config = InstructionCacheConfig(
+//              cacheSize = 1024*16,
+//              bytePerLine = 32,
+//              wayCount = 1,
+//              addressWidth = 32,
+//              cpuDataWidth = 32,
+//              memDataWidth = 32,
+//              catchIllegalAccess = false,
+//              catchAccessFault = true,
+//              catchMemoryTranslationMiss = false,
+//              asyncTagMemory = false,
+//              twoCycleRam = false
+//            )//,
 //            memoryTranslatorPortConfig = MemoryTranslatorPortConfig(
 //              portTlbSize = 4
 //            )
-          ),
+//          ),
 //          new DBusSimplePlugin(
 //            catchAddressMisaligned = true,
 //            catchAccessFault = true,
@@ -122,7 +122,7 @@ object TestsWorkspace {
           ),
 //          new DivPlugin,
           new CsrPlugin(CsrPluginConfig.all(0x80000020l).copy(deterministicInteruptionEntry = false)),
-//          new DebugPlugin(ClockDomain.current.clone(reset = Bool().setName("debugReset"))),
+          new DebugPlugin(ClockDomain.current.clone(reset = Bool().setName("debugReset"))),
           new BranchPlugin(
             earlyBranch = true,
             catchAddressMisaligned = true,

src/main/scala/vexriscv/plugin/DebugPlugin.scala

@@ -105,6 +105,8 @@ class DebugPlugin(val debugClockDomain : ClockDomain) extends Plugin[VexRiscv] w
   var io : DebugExtensionIo = null
   val injectionAsks = ArrayBuffer[(Stage, Bool)]()
   var isInjectingOnDecode : Bool = null
+  var injectionPort : Stream[Bits] = null
+
   override def isInjecting(stage: Stage) : Bool = if(stage == pipeline.decode) isInjectingOnDecode else False
 
   object IS_EBREAK extends Stageable(Bool)
@@ -126,6 +128,7 @@ class DebugPlugin(val debugClockDomain : ClockDomain) extends Plugin[VexRiscv] w
     ))
 
     isInjectingOnDecode = Bool()
+    injectionPort = pipeline.service(classOf[IBusFetcher]).getInjectionPort()
   }
 
 
@@ -174,35 +177,39 @@ class DebugPlugin(val debugClockDomain : ClockDomain) extends Plugin[VexRiscv] w
           is(1) {
             when(io.bus.cmd.wr) {
               insertDecodeInstruction := True
-              //TODO !!!!
-              decode.arbitration.isValid.getDrivingReg setWhen (firstCycle)
-              decode.arbitration.haltItself setWhen (secondCycle)
-              io.bus.cmd.ready := !firstCycle && !secondCycle && execute.arbitration.isValid
+//              decode.arbitration.isValid.getDrivingReg setWhen (firstCycle)
+//              decode.arbitration.haltItself setWhen (secondCycle)
+//              io.bus.cmd.ready := !firstCycle && !secondCycle && execute.arbitration.isValid
+              io.bus.cmd.ready := injectionPort.fire
             }
           }
         }
       }
 
-      Component.current.addPrePopTask(() => {
-        //Check if the decode instruction is driven by a register
-        val instructionDriver = try {decode.input(INSTRUCTION).getDrivingReg} catch { case _ : Throwable => null}
-        if(instructionDriver != null){ //If yes =>
-          //Insert the instruction by writing the "fetch to decode instruction register",
-          // Work even if it need to cross some hierarchy (caches)
-          instructionDriver.component.rework {
-            when(insertDecodeInstruction.pull()) {
-              instructionDriver := io.bus.cmd.data.pull()
-            }
-          }
-        } else{
-          //Insert the instruction via a mux in the decode stage
-          when(RegNext(insertDecodeInstruction)){
-            decode.input(INSTRUCTION) := RegNext(io.bus.cmd.data)
-          }
-        }
-      })
+      injectionPort.valid := RegNext(insertDecodeInstruction) init(False) clearWhen(injectionPort.fire)
+      injectionPort.payload := RegNext(io.bus.cmd.data)
 
 
+//      Component.current.addPrePopTask(() => {
+//        //Check if the decode instruction is driven by a register
+//        val instructionDriver = try {decode.input(INSTRUCTION).getDrivingReg} catch { case _ : Throwable => null}
+//        if(instructionDriver != null){ //If yes =>
+//          //Insert the instruction by writing the "fetch to decode instruction register",
+//          // Work even if it need to cross some hierarchy (caches)
+//          instructionDriver.component.rework {
+//            when(insertDecodeInstruction.pull()) {
+//              instructionDriver := io.bus.cmd.data.pull()
+//            }
+//          }
+//        } else{
+//          //Insert the instruction via a mux in the decode stage
+//          when(RegNext(insertDecodeInstruction)){
+//            decode.input(INSTRUCTION) := RegNext(io.bus.cmd.data)
+//          }
+//        }
+//      })
+//
+
       when(execute.arbitration.isFiring && execute.input(IS_EBREAK)) {
         decode.arbitration.haltByOther := True
         decode.arbitration.flushAll := True

src/main/scala/vexriscv/plugin/Fetcher.scala

@@ -31,6 +31,12 @@ abstract class IBusFetcherImpl(val catchAccessFault : Boolean,
   lazy val decodeNextPc = UInt(32 bits)
   def nextPc() = (False, decodeNextPc)
 
+  var injectionPort : Stream[Bits] = null
+  override def getInjectionPort() = {
+    injectionPort = Stream(Bits(32 bits))
+    injectionPort
+  }
+
   var predictionJumpInterface : Flow[UInt] = null
 
   override def haltIt(): Unit = fetcherHalt := True
@@ -281,6 +287,14 @@ abstract class IBusFetcherImpl(val catchAccessFault : Boolean,
 //        decodeExceptionPort.code  := 1
 //        decodeExceptionPort.badAddr := decode.input(PC)
 //      }
+
+      if(injectionPort != null){
+        injectionPort.ready := !decode.arbitration.isStuck
+        when(injectionPort.valid) {
+          decode.arbitration.isValid := True
+          decode.insert(INSTRUCTION) := injectionPort.payload
+        }
+      }
     }
 
     prediction match {