debug: remove preexec. Simplify the state machine since you can always just 'execute' once.

src/main/scala/uncore/devices/debug/Debug.scala

@@ -52,19 +52,14 @@ object DsbRegAddrs{
   def RESUMING     = 0x108
   def EXCEPTION    = 0x10C
 
-  def FLAGS        = 0x400
-
-  def ROMBASE      = 0x800
-  def RESUME       = 0x804
-
   def WHERETO      = 0x300
-  def ABSTRACT     = 0x340 - 8
+  def ABSTRACT     = 0x304
-  def PROGBUF      = 0x340
+  def PROGBUF      = 0x304 + 8
-
   // This shows up in HartInfo
-  def DATA         = 0x380
+  def DATA(cfg: DebugModuleConfig) = {PROGBUF + (cfg.nProgramBufferWords * 4)}
 
-  //Not implemented: Serial.
+  def FLAGS        = 0x400
+  def ROMBASE      = 0x800
  
 }
 
@@ -226,8 +221,8 @@ class DebugCtrlBundle (nComponents: Int)(implicit val p: Parameters) extends Par
   *                      provide the default MTVEC since it is mapped
   *                      to address 0x0.
   *  
-  *  DebugModule is responsible for control registers and RAM. The Debug ROM is in a 
+  *  DebugModule is responsible for control registers and RAM, and
-  *  seperate module. It runs partially off of the dmiClk (e.g. TCK) and
+  *  Debug ROM. It runs partially off of the dmiClk (e.g. TCK) and
   *  the TL clock. Therefore, it is divided into "Outer" portion (running
   *  of off dmiClock and dmiReset) and "Inner" (running off tlClock and tlReset).
   *  This allows DMCONTROL.haltreq, hartsel, dmactive, and ndreset to be
@@ -354,8 +349,7 @@ class TLDebugModuleOuter(device: Device)(implicit p: Parameters) extends LazyMod
       io.debugInterrupts(component)(0) := debugIntRegs(component)
     }
 
-    // Halt request registers are written by write to DMCONTROL.haltreq
+    // Halt request registers are set & cleared by writes to DMCONTROL.haltreq
-    // and cleared by writes to DMCONTROL.resumereq.
     // resumereq also causes the core to execute a 'dret',
     // so resumereq is passed through to Inner.
     // hartsel must also be used by the DebugModule state machine,
@@ -367,11 +361,8 @@ class TLDebugModuleOuter(device: Device)(implicit p: Parameters) extends LazyMod
       when (~dmactive) {
         debugIntNxt(component) := false.B
       }. otherwise {
-        when (DMCONTROLWrEn) {
+        when (DMCONTROLWrEn && DMCONTROLWrData.hartsel === component.U) {
-          when (DMCONTROLWrData.hartsel === component.U) {
+          debugIntNxt(component) := DMCONTROLWrData.haltreq
-            debugIntNxt(component) := (debugIntRegs(component) | DMCONTROLWrData.haltreq) &
-            ~(DMCONTROLWrData.resumereq)
-          }
         }
       }
     }
@@ -549,7 +540,7 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
     val HARTINFORdData = Wire (init = (new HARTINFOFields()).fromBits(0.U))
     HARTINFORdData.dataaccess  := true.B
     HARTINFORdData.datasize    := cfg.nAbstractDataWords.U
-    HARTINFORdData.dataaddr    := DsbRegAddrs.DATA.U
+    HARTINFORdData.dataaddr    := DsbRegAddrs.DATA(cfg).U
     HARTINFORdData.nscratch    := cfg.nScratch.U
 
     //----HALTSUM (and halted registers)
@@ -597,8 +588,7 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
       }.elsewhen (errorHaltResume) {
         ABSTRACTCSReg.cmderr := DebugAbstractCommandError.ErrHaltResume.id.U
       }.otherwise {
-        //TODO: Should be write-1-to-clear & ~ABSTRACTCSWrData.cmderr
+        when (ABSTRACTCSWrEn){
-        when (ABSTRACTCSWrEn /* && ABSTRACTCSWrData.cmderr === 0.U*/){
           ABSTRACTCSReg.cmderr := ABSTRACTCSReg.cmderr & ~(ABSTRACTCSWrData.cmderr);
         }
       }
@@ -741,35 +731,15 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
     // "Variable" ROM Generation
     //--------------------------------------------------------------
 
-    val goProgramBuffer = Wire(init = false.B)
+    val goReg        = Reg(Bool())
-    val goAbstract      = Wire(init = false.B)
+    val goAbstract   = Wire(init = false.B)
-
-    val whereToReg = Reg(UInt(32.W))
-
-    val jalProgBuf  = Wire(init = (new GeneratedUJ()).fromBits(rocket.Instructions.JAL.value.U))
-    jalProgBuf.setImm(PROGBUF - WHERETO)
-    jalProgBuf.rd := 0.U
-
     val jalAbstract  = Wire(init = (new GeneratedUJ()).fromBits(rocket.Instructions.JAL.value.U))
     jalAbstract.setImm(ABSTRACT - WHERETO)
-    jalProgBuf.rd := 0.U
-
-    when (~io.dmactive) {
-      whereToReg := 0.U
-    }.otherwise{
-      when (goProgramBuffer) {
-        whereToReg := jalProgBuf.asUInt()
-      }.elsewhen (goAbstract) {
-        whereToReg := jalAbstract.asUInt()
-      }
-    }
-
-    val goReg            = Reg(Bool())
 
     when (~io.dmactive){
       goReg := false.B
     }.otherwise {
-      when (goProgramBuffer | goAbstract) {
+      when (goAbstract) {
         goReg := true.B
       }.elsewhen (hartGoingWrEn){
         assert(hartGoingId === 0.U, "Unexpected 'GOING' hart.")//Chisel3 #540 %x, expected %x", hartGoingId, 0.U)
@@ -849,14 +819,14 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
     abstractGeneratedI.rd     := (accessRegisterCommandReg.regno & 0x1F.U)
     abstractGeneratedI.funct3 := accessRegisterCommandReg.size
     abstractGeneratedI.rs1    := 0.U
-    abstractGeneratedI.imm    := DATA.U
+    abstractGeneratedI.imm    := DATA(cfg).U
 
     abstractGeneratedS.opcode := ((new GeneratedS()).fromBits(rocket.Instructions.SW.value.U)).opcode
-    abstractGeneratedS.immlo  := (DATA & 0x1F).U
+    abstractGeneratedS.immlo  := (DATA(cfg) & 0x1F).U
     abstractGeneratedS.funct3 := accessRegisterCommandReg.size
     abstractGeneratedS.rs1    := 0.U
     abstractGeneratedS.rs2    := (accessRegisterCommandReg.regno & 0x1F.U)
-    abstractGeneratedS.immhi  := (DATA >> 5).U
+    abstractGeneratedS.immhi  := (DATA(cfg) >> 5).U
 
     nop := ((new GeneratedI()).fromBits(rocket.Instructions.ADDI.value.U))
     nop.rd   := 0.U
@@ -872,7 +842,7 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
           abstractGeneratedS.asUInt()),
         nop.asUInt()
       )
-      abstractGeneratedMem(1) := Mux(/*TODO accessRegisterCommandReg.postexec*/ false.B,
+      abstractGeneratedMem(1) := Mux(accessRegisterCommandReg.postexec,
         nop.asUInt(),
         rocket.Instructions.EBREAK.value.U)
     }
@@ -887,15 +857,16 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
       GOING       -> Seq(WNotify(sbIdWidth, hartGoingId,  hartGoingWrEn)),
       RESUMING    -> Seq(WNotify(sbIdWidth, hartResumingId,  hartResumingWrEn)),
       EXCEPTION   -> Seq(WNotify(sbIdWidth, hartExceptionId,  hartExceptionWrEn)),
-      DATA        -> abstractDataMem.map(x => RegField(8, x)),
+      DATA(cfg)   -> abstractDataMem.map(x => RegField(8, x)),
       PROGBUF     -> programBufferMem.map(x => RegField(8, x)),
 
       // These sections are read-only.
-      ROMBASE     -> DebugRomContents().map(x => RegField.r(8, (x & 0xFF).U(8.W))),
+      WHERETO     -> Seq(RegField.r(32, jalAbstract.asUInt)),
+      ABSTRACT    -> abstractGeneratedMem.map{x => RegField.r(32, x)},
       FLAGS       -> flags.map{x => RegField.r(8, x.asUInt())},
-      WHERETO     -> Seq(RegField.r(32, whereToReg)),
+      ROMBASE     -> DebugRomContents().map(x => RegField.r(8, (x & 0xFF).U(8.W)))
-      ABSTRACT    -> abstractGeneratedMem.map(x => RegField.r(32, x))
+
-      )
+    )
 
     // Override System Bus accesses with dmactive reset.
     when (~io.dmactive){
@@ -909,7 +880,7 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
 
     object CtrlState extends scala.Enumeration {
       type CtrlState = Value
-      val Waiting, CheckGenerate, PreExec, Abstract, PostExec = Value
+      val Waiting, CheckGenerate, Exec = Value
 
       def apply( t : Value) : UInt = {
         t.id.U(log2Up(values.size).W)
@@ -963,7 +934,6 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
       when (wrAccessRegisterCommand || regAccessRegisterCommand) {
         ctrlStateNxt := CtrlState(CheckGenerate)
       }
-
     }.elsewhen (ctrlStateReg === CtrlState(CheckGenerate)){
 
       // We use this state to ensure that the COMMAND has been
@@ -977,47 +947,11 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
         errorHaltResume := true.B
         ctrlStateNxt := CtrlState(Waiting)
       }.otherwise {
-        when (accessRegisterCommandReg.preexec) {
+        ctrlStateNxt := CtrlState(Exec)
-          ctrlStateNxt    := CtrlState(PreExec)
-          goProgramBuffer := true.B
-        }.otherwise {
-          ctrlStateNxt := CtrlState(Abstract)
-          goAbstract := true.B
-        }
-      }
-    }.elsewhen (ctrlStateReg === CtrlState(PreExec)) {
-
-      // We can't just look at 'hartHalted' here, because
-      // hartHaltedWrEn is overloaded to mean 'got an ebreak'
-      // which may have happened when we were already halted.
-      when(goReg === false.B && hartHaltedWrEn && (cfg.hartIdToHartSel(hartHaltedId) === selectedHartReg)){
-        ctrlStateNxt := CtrlState(Abstract)
         goAbstract := true.B
       }
-      when(hartExceptionWrEn) {
-        assert(hartExceptionId === 0.U,  "Unexpected 'EXCEPTION' hart")// Chisel3 #540, %x, expected %x", hartExceptionId, 0.U)
-        ctrlStateNxt := CtrlState(Waiting)
-        errorException := true.B
-      }
-    }.elsewhen (ctrlStateReg === CtrlState(Abstract)) {
     
-      // We can't just look at 'hartHalted' here, because
+    }.elsewhen (ctrlStateReg === CtrlState(Exec)) {
-      // hartHaltedWrEn is overloaded to mean 'got an ebreak'
-      // which may have happened when we were already halted.
-      when(goReg === false.B && hartHaltedWrEn && (cfg.hartIdToHartSel(hartHaltedId) === selectedHartReg)){
-        when (accessRegisterCommandReg.postexec) {
-          ctrlStateNxt := CtrlState(PostExec)
-          goProgramBuffer := true.B
-        }.otherwise {
-          ctrlStateNxt := CtrlState(Waiting)
-        }
-      }
-      when(hartExceptionWrEn) {
-        assert(hartExceptionId === 0.U, "Unexpected 'EXCEPTION' hart")//Chisel3 #540 %x, expected %x", hartExceptionId, selectedHartReg)
-        ctrlStateNxt := CtrlState(Waiting)
-        errorUnsupported := true.B
-      }
-    }.elsewhen (ctrlStateReg === CtrlState(PostExec)) {
 
       // We can't just look at 'hartHalted' here, because
       // hartHaltedWrEn is overloaded to mean 'got an ebreak'
@@ -1027,7 +961,7 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
       }
       when(hartExceptionWrEn) {
         assert(hartExceptionId === 0.U, "Unexpected 'EXCEPTION' hart")//Chisel3 #540, %x, expected %x", hartExceptionId, 0.U)
-        ctrlStateNxt := CtrlState(Waiting)
+          ctrlStateNxt := CtrlState(Waiting)
         errorException := true.B
       }
     }
@@ -1040,6 +974,7 @@ class TLDebugModuleInner(device: Device, getNComponents: () => Int)(implicit p:
   }
 }
 
+
 // Wrapper around TL Debug Module Inner and an Async DMI Sink interface.
 // Handles the synchronization of dmactive, which is used as a synchronous reset
 // inside the Inner block.

src/main/scala/uncore/devices/debug/abstract_commands.scala

@@ -28,8 +28,7 @@ class ACCESS_REGISTERFields extends Bundle {
   */
   val size = UInt(3.W)
 
-  // HACK -- for now I have not yet deleted preexecval reserved1 = UInt(1.W)
+  val reserved1 = UInt(1.W)
-  val preexec = Bool()
   
   /* When 1, execute the program in the Program Buffer exactly once
             after performing the transfer, if any.