Merge pull request #316 from ucb-bar/dynamic-reset-vector

Allow reset vector to be set dynamically

src/main/scala/coreplex/Configs.scala

@@ -131,8 +131,7 @@ class BaseCoreplexConfig extends Config (
       case UseCompressed => true
       case DMKey => new DefaultDebugModuleConfig(site(NTiles), site(XLen))
       case NCustomMRWCSRs => 0
-      case ResetVector => BigInt(0x1000)
-      case MtvecInit => BigInt(0x1010)
+      case MtvecInit => None
       case MtvecWritable => true
       //Uncore Paramters
       case LNEndpoints => site(TLKey(site(TLId))).nManagers + site(TLKey(site(TLId))).nClients

src/main/scala/coreplex/Coreplex.scala

@@ -58,6 +58,7 @@ abstract class Coreplex(implicit val p: Parameters, implicit val c: CoreplexConf
     val debug = new DebugBusIO()(p).flip
     val clint = Vec(c.nTiles, new CoreplexLocalInterrupts).asInput
     val success: Option[Bool] = hasSuccessFlag.option(Bool(OUTPUT))
+    val resetVector = UInt(INPUT, p(XLen))
   }
 
   def hasSuccessFlag: Boolean = false
@@ -153,6 +154,7 @@ class DefaultCoreplex(tp: Parameters, tc: CoreplexConfig) extends Coreplex()(tp,
       tile.io.interrupts.seip.foreach(_ := plic.io.harts(plic.cfg.context(i, 'S')))
       tile.io.interrupts.debug := debugModule.io.debugInterrupts(i)
       tile.io.hartid := i
+      tile.io.resetVector := io.resetVector
     }
 
     val tileSlavePorts = (0 until tc.nTiles) map (i => s"int:dmem$i") filter (ioAddrMap contains _)

src/main/scala/rocket/csr.scala

@@ -227,7 +227,11 @@ class CSRFile(implicit p: Parameters) extends CoreModule()(p)
   val reg_mcause = Reg(Bits(width = xLen))
   val reg_mbadaddr = Reg(UInt(width = vaddrBitsExtended))
   val reg_mscratch = Reg(Bits(width = xLen))
-  val reg_mtvec = Reg(init=UInt(p(MtvecInit), paddrBits min xLen))
+  val mtvecWidth = paddrBits min xLen
+  val reg_mtvec = p(MtvecInit) match {
+    case Some(addr) => Reg(init=UInt(addr, mtvecWidth))
+    case None => Reg(UInt(width = mtvecWidth))
+  }
   val reg_mucounteren = Reg(UInt(width = 32))
   val reg_mscounteren = Reg(UInt(width = 32))
   val delegable_counters = (BigInt(1) << (nPerfCounters + CSR.firstHPM)) - 1

src/main/scala/rocket/frontend.scala

@@ -35,6 +35,7 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
     val cpu = new FrontendIO().flip
     val ptw = new TLBPTWIO()
     val mem = new ClientUncachedTileLinkIO
+    val resetVector = UInt(INPUT, vaddrBitsExtended)
   }
 
   val icache = Module(new ICache(latency = 2))
@@ -45,7 +46,7 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
   val s1_speculative = Reg(Bool())
   val s1_same_block = Reg(Bool())
   val s2_valid = Reg(init=Bool(true))
-  val s2_pc = Reg(init=UInt(p(ResetVector)))
+  val s2_pc = Reg(init=io.resetVector)
   val s2_btb_resp_valid = Reg(init=Bool(false))
   val s2_btb_resp_bits = Reg(new BTBResp)
   val s2_xcpt_if = Reg(init=Bool(false))

src/main/scala/rocket/rocket.scala

@@ -27,8 +27,7 @@ case object FastJAL extends Field[Boolean]
 case object CoreInstBits extends Field[Int]
 case object NCustomMRWCSRs extends Field[Int]
 case object MtvecWritable extends Field[Boolean]
-case object MtvecInit extends Field[BigInt]
-case object ResetVector extends Field[BigInt]
+case object MtvecInit extends Field[Option[BigInt]]
 case object NBreakpoints extends Field[Int]
 case object NPerfCounters extends Field[Int]
 case object NPerfEvents extends Field[Int]

src/main/scala/rocket/tile.scala

@@ -34,6 +34,7 @@ abstract class Tile(clockSignal: Clock = null, resetSignal: Bool = null)
     val hartid = UInt(INPUT, p(XLen))
     val interrupts = new TileInterrupts().asInput
     val slave = (p(DataScratchpadSize) > 0).option(new ClientUncachedTileLinkIO().flip)
+    val resetVector = UInt(INPUT, p(XLen))
   }
 
   val io = new TileIO
@@ -58,6 +59,7 @@ class RocketTile(clockSignal: Clock = null, resetSignal: Bool = null)
   core.io.interrupts := io.interrupts
   core.io.hartid := io.hartid
   icache.io.cpu <> core.io.imem
+  icache.io.resetVector := io.resetVector
 
   val fpuOpt = p(FPUKey).map(cfg => Module(new FPU(cfg)))
   fpuOpt.foreach(fpu => core.io.fpu <> fpu.io)

src/main/scala/rocketchip/Periphery.scala

@@ -311,7 +311,9 @@ trait PeripheryBootROM extends LazyModule {
   implicit val p: Parameters
   val peripheryBus: TLXbar
 
-  val rom = LazyModule(new TLROM(0x1000, 0x1000, GenerateBootROM(p)) { override def name = "bootrom" })
+  val address = 0x1000
+  val size = 0x1000
+  val rom = LazyModule(new TLROM(address, size, GenerateBootROM(p, address)) { override def name = "bootrom" })
   rom.node := TLFragmenter(peripheryBus.node, 4, 256)
 }
 
@@ -365,3 +367,10 @@ trait PeripheryTestBusMasterModule {
   implicit val p: Parameters
   val outer: PeripheryTestBusMaster
 }
+
+/////
+
+trait HardwiredResetVector {
+  val coreplex: Coreplex
+  coreplex.io.resetVector := UInt(0x1000) // boot ROM
+}

src/main/scala/rocketchip/Top.scala

@@ -53,11 +53,11 @@ abstract class BaseTop(q: Parameters) extends LazyModule {
   peripheryBus.node := TLBuffer(TLWidthWidget(TLHintHandler(legacy.node), legacy.tlDataBytes))
 }
 
-class BaseTopBundle(val p: Parameters, val c: Coreplex) extends ParameterizedBundle()(p) {
+abstract class BaseTopBundle(val p: Parameters, val c: Coreplex) extends ParameterizedBundle()(p) {
   val success = c.hasSuccessFlag.option(Bool(OUTPUT))
 }
 
-class BaseTopModule[+L <: BaseTop, +B <: BaseTopBundle](val p: Parameters, l: L, b: Coreplex => B) extends LazyModuleImp(l) {
+abstract class BaseTopModule[+L <: BaseTop, +B <: BaseTopBundle](val p: Parameters, l: L, b: Coreplex => B) extends LazyModuleImp(l) {
   val outer: L = l
 
   val coreplex = p(BuildCoreplex)(p, outer.c)
@@ -103,6 +103,7 @@ class ExampleTopBundle(p: Parameters, c: Coreplex) extends BaseTopBundle(p, c)
 class ExampleTopModule[+L <: ExampleTop, +B <: ExampleTopBundle](p: Parameters, l: L, b: Coreplex => B) extends BaseTopModule(p, l, b)
     with PeripheryBootROMModule with PeripheryDebugModule with PeripheryExtInterruptsModule with PeripheryCoreplexLocalInterrupterModule
     with PeripheryMasterMemModule with PeripheryMasterMMIOModule with PeripherySlaveModule
+    with HardwiredResetVector
 
 /** Example Top with TestRAM */
 class ExampleTopWithTestRAM(q: Parameters) extends ExampleTop(q)

src/main/scala/rocketchip/Utils.scala

@@ -168,21 +168,14 @@ object GenerateConfigString {
 }
 
 object GenerateBootROM {
-  def apply(p: Parameters) = {
+  def apply(p: Parameters, address: BigInt) = {
     val romdata = Files.readAllBytes(Paths.get(p(BootROMFile)))
     val rom = ByteBuffer.wrap(romdata)
 
     rom.order(ByteOrder.LITTLE_ENDIAN)
 
-    // for now, have the reset vector jump straight to memory
-    val memBase = (
-      if (p(GlobalAddrMap) contains "mem") p(GlobalAddrMap)("mem")
-      else p(GlobalAddrMap)("io:int:dmem0")
-    ).start
-    val resetToMemDist = memBase - p(ResetVector)
-    require(resetToMemDist == (resetToMemDist.toInt >> 12 << 12))
-    val configStringAddr = p(ResetVector).toInt + rom.capacity
-
+    require(address == address.toInt)
+    val configStringAddr = address.toInt + rom.capacity
     require(rom.getInt(12) == 0,
       "Config string address position should not be occupied by code")
     rom.putInt(12, configStringAddr)