Fixed SPL being executable without privilege

src/main/kotlin/Main.kt

@@ -1,6 +1,7 @@
 import ch.qos.logback.classic.LoggerContext
 import ch.qos.logback.core.util.StatusPrinter
 import com.thequux.mcpdp.core.CPU
+import com.thequux.mcpdp.debug.FlightRecorder
 import com.thequux.mcpdp.debug.LoggingCollector
 import com.thequux.mcpdp.debug.NullTracer
 import com.thequux.mcpdp.debug.Tracer
@@ -24,7 +25,9 @@ fun main(args: Array<String>) {
     var mbus = MemBus(65536)
     val tracer = Tracer()
     val loggingCollector = LoggingCollector()
-    tracer.addCollector(loggingCollector)
+//    tracer.addCollector(loggingCollector)
+    val recorder = FlightRecorder(3000)
+    tracer.addCollector(recorder)
     var cpu = CPU(mbus, if (CPU.debugMode) tracer else NullTracer())
     val console = DL11(mbus.unibus, tb.input(), tb.output()).apply { mount(mbus.unibus) }
     try {
@@ -34,19 +37,22 @@ fun main(args: Array<String>) {
         console.start()
 
         cpu.loadAbs(File(args[0]))
+        cpu.core.setw(0x3C78u, 0u) // halt instead of restart
         cpu.runState = CPU.RunState.RUNNING
         cpu.pc = 0x80u
         val start = System.nanoTime()
-//        var ninsn = cpu.run(600000000)
-        var ninsn = cpu.run(376670)
+//        var ninsn = cpu.run(60000000)
         cpu.tracer = tracer
-        ninsn += cpu.run(30)
+        var ninsn = cpu.run(323227)
+//        var ninsn = cpu.run(13300)
+//        ninsn += cpu.run(10)
+        recorder.dump(System.out)
         cpu.dumpReg()
         val end = System.nanoTime()
 
         System.err.println("Halted at 0${cpu.pc.toString(8)}")
         val time = (end - start).toDouble() / 1_000_000_000.0
-        println("Executed ${ninsn} in ${time}s: ${ninsn / time / 1_000_000} MIPS")
+        System.err.println("Executed ${ninsn} in ${time}s: ${ninsn / time / 1_000_000} MIPS")
     } finally {
         println("Exiting")
         console.stop()

src/main/kotlin/com/thequux/mcpdp/core/CPU.kt

@@ -82,7 +82,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
                     0x0001 -> runState = RunState.WAIT_FOR_INTERRUPT // WAIT
                     0x0002 -> { // RTI
                         pc = stack_pop()
-                        psw = stack_pop() // TODO: check privilege on mode; check psw[11]
+                        setPSW(stack_pop(), cur_mode == 0) // TODO: check privilege on mode; check psw[11]
                     } // RTI
                     0x0003 -> setTrap(TrapReason.BPT) // BPT
                     0x0004 -> setTrap(TrapReason.IOT) // IOT
@@ -94,7 +94,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
                     } // bus reset TODO: bus init
                     0x0006 -> {
                         pc = stack_pop()
-                        psw = stack_pop()
+                        setPSW(stack_pop(), cur_mode == 0)
                         allowT = false
                     } // RTT
                     in 0x40..0x7f -> {
@@ -111,7 +111,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
                         registers[reg] = stack_pop()
                     } // RTS
                     in 0x98..0x9F -> {
-                        psw_priority = opcode and 0x7
+                        if (cur_mode == 0) psw_priority = opcode and 0x7
                     } // SPL
                     in 0xA0..0xBF -> {
                         val flag = opcode bit 4
@@ -768,7 +768,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
     val core = PagingUnit(mbus, this)
 
     var runState: RunState = RunState.HALTED
-    var psw: UShort
+    val psw: UShort
         get() {
             var res = 0
             if (C) { res = res or 0x0001 }
@@ -781,26 +781,33 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
             res = res or (registerSet shl 11)
             return res.toUShort()
         }
-        set(value) {
-            var newpsw = value.toInt()
-            C = value bit 0
-            V = value bit 1
-            Z = value bit 2
-            N = value bit 3
-            T = value bit 4 // TODO: handle suspended trap
-            psw_priority = newpsw shr 5 and 7
+
+    fun setPSW(value: UShort, allowEsc: Boolean) {
+        var newpsw = value.toInt()
+        C = value bit 0
+        V = value bit 1
+        Z = value bit 2
+        N = value bit 3
+        T = value bit 4 // TODO: handle suspended trap
+        if (allowEsc) {
             registerSet = newpsw shr 11 and 1
             cur_mode = newpsw shr 14
-
+            prv_mode = newpsw shr 12 and 3
+            psw_priority = newpsw shr 5 and 7
+        } else {
+            registerSet = registerSet or (newpsw shr 11 and 1)
+            cur_mode = cur_mode or (newpsw shr 14 and 3)
+            prv_mode = prv_mode or (newpsw shr 12 and 3)
         }
+    }
 
     private var cur_mode: Int = 0
         set(value) {
-            prv_mode = field
+//            prv_mode = field
             shadow_r6[field] = sp
             field = if (value == 2) 3 else value
             sp = shadow_r6[field]
-            core.mode = value
+            core.mode = field
         }
     private var prv_mode: Int = 0
     private var psw_priority: Int = 0
@@ -817,6 +824,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
 
     private var registerSet: Int = 0
         set(value) {
+            if (value == field) return
             if (value !in 0..1) {
                 throw ProgrammerError("Invalid register set number")
             }
@@ -830,9 +838,12 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
         }
 
     private var cc: UShort
-        get() = psw and 0xFu
+        get() = 0.bit(3, N).bit(2, Z).bit(1, C).bit(0, C).toUShort()
         set(value) {
-            psw = (psw and 0xFFFu) or (value and 0xFu)
+            N = value bit 3
+            Z = value bit 2
+            V = value bit 1
+            C = value bit 0
         }
     private var pirq: UShort = 0u
     	set(value) {
@@ -1031,11 +1042,11 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
     fun trapRed() {
         // This is handled separately because otherwise the stack push
         // would itself trigger a red trap
-        logger.warn("Stack RED")
+//        logger.warn("Stack RED")
         cpu_err = cpu_err or CPU_ERR_STK_RED
         val old_psw = psw
-        psw = core.getw(6u)
-        core.setw(2u, psw)
+        setPSW(core.getw(6u), true)
+        core.setw(2u, old_psw)
         core.setw(0u, pc)
         sp = 0u
         trapReq = trapReq and TrapReason.RED.clear.inv()
@@ -1084,7 +1095,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
             } else {
                 val pirqLvl = pirq.toInt() shr 1 and 7;
                 if (pirqLvl > psw_priority) {
-//                    logger.debug("PIRQ{} trap to 0xA0", pirqLvl)
+                    logger.debug("PIRQ{} trap to 0xA0", pirqLvl)
                     callVector(0xA0u)
                 }
             }
@@ -1124,7 +1135,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
                     setTrap(TrapReason.NXM)
                 }
             }
-            logger.warn("Threw error: $error")
+//            logger.warn("Threw error: $error")
         } catch (_: InvalidOpcodeException) {
             setTrap(TrapReason.ILL)
         } catch (_: EndCycle) {
@@ -1144,8 +1155,9 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
         var ninsn: Long = 0
         while (runState == RunState.RUNNING && ninsn < nstep) {
             ninsn++
-            if (pc == 0x344A.toUShort()) {
-                pc = pc
+            if (pc == 0x3224.toUShort()) {
+                runState = runState
+                runState = RunState.HALTED
             }
             step()
         }
@@ -1154,8 +1166,8 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
 
     fun callVector(vector: UShort) {
         val old_psw = psw
-        // update PSW first so that this gets pushed to the
-        psw = core.getw((vector + 2u).toUShort())
+        val newPSW = core.getw((vector + 2u).toUShort()) and 0xCFFFu or (cur_mode shl 12).toUShort()
+        setPSW(newPSW, true)
         stack_push(old_psw)
         stack_push(pc)
         pc = core.getw(vector)
@@ -1188,7 +1200,11 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
             0x3_FFF6u -> cpu_err = value
             0x3_FFFAu -> pirq = value
             0x3_FFFCu -> stack_limit = value and 0xFF00u // stack limit
-            0x3_FFFEu -> psw = value or (cur_mode.toUShort() shl 14) // writing to PSW can only increase current mode
+            0x3_FFFEu -> {
+                setPSW(value, true)
+                // explicitly switch RS if necessary
+//                registerSet = (value shr 11 and 1u).toInt()
+            } // writing to PSW can only increase current mode
             else -> {
                 println("Bus error at ${addr.toString(16)}: ${value.toString(16)}")
                 throw BusTimeoutError(addr)
@@ -1202,7 +1218,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
             trapRed()
             throw EndCycle()
         } else if (sp < stack_limit + 256u) {
-            logger.warn("Stack YLW")
+//            logger.warn("Stack YLW")
             // stack limit yellow
             cpu_err = cpu_err or CPU_ERR_STK_YLW
             setTrap(TrapReason.YEL)

src/main/kotlin/com/thequux/mcpdp/core/PagingUnit.kt

@@ -5,6 +5,7 @@ import com.thequux.mcpdp.ext.bit.*
 import com.thequux.mcpdp.peripheral.Unibus
 import com.thequux.mcpdp.util.ProgrammerError
 import kotlin.math.max
+import kotlin.math.min
 
 enum class AccessAction {
     Allow,
@@ -77,8 +78,8 @@ class PagingUnit(val pspace: PAddressSpace, val cpu: CPU): VAddressSpace {
     val unibusMap: PAddressSpace = UnibusMap()
 
     private inner class PageTable(val mode: Int, val dspace: Boolean) {
-        val par = UShortArray(16) { 0U }
-        val pdr = Array(16) { PDR() }
+        val par = UShortArray(8) { 0U }
+        val pdr = Array(8) { PDR() }
 
 
         fun setMmr0(causeBit: Int, apf: Int, completed: Boolean = false) {
@@ -121,7 +122,7 @@ class PagingUnit(val pspace: PAddressSpace, val cpu: CPU): VAddressSpace {
                     throw EndCycle()
                 }
             }
-            val tmp1 = addr.toUInt() + (par.toUInt() shl 6) and mapMode.addrMask
+            val tmp1 = addr.toUInt().and(0x1FFFu) + (par.toUInt() shl 6) and mapMode.addrMask
             if (tmp1 and mapMode.hipageMask == mapMode.hipageMask) {
                 return tmp1 or 0x3C_0000u
             } else {
@@ -142,7 +143,7 @@ class PagingUnit(val pspace: PAddressSpace, val cpu: CPU): VAddressSpace {
             enable22bit -> MManMode.MM_22
             else -> MManMode.MM_18
         }
-        modeSpace = if (mapMode.mmanEnable) modeVTabs[max(mode, 2)] else noMmanSpace
+        modeSpace = if (mapMode.mmanEnable) modeVTabs[min(mode, 2)] else noMmanSpace
     }
 
     fun getSpace(mode: Int): VAddressSpace = if (mapMode.mmanEnable) modeVTabs[max(mode, 2)] else noMmanSpace
@@ -172,7 +173,7 @@ class PagingUnit(val pspace: PAddressSpace, val cpu: CPU): VAddressSpace {
 
 
     private inner class ModeVSpace(private val iSpace: PageTable, private val dSpace: PageTable, var useDSpace: Boolean): VAddressSpace {
-        private fun getSpace(dspace: Boolean): PageTable = if (dspace) dSpace else iSpace
+        private fun getSpace(dspace: Boolean): PageTable = if (dspace && useDSpace) dSpace else iSpace
         override fun getw(addr: UShort, dspace: Boolean): UShort = pspace.getw(getSpace(dspace).map(addr, write = false))
 
         override fun getb(addr: UShort): UByte = pspace.getb(dSpace.map(addr, write = false))

src/main/kotlin/com/thequux/mcpdp/debug/Disassembler.kt

@@ -86,7 +86,11 @@ class Disassembler {
     fun dasm_at(loc: UShort, istream: UShortArray): String {
         opc = loc
         this.istream = istream
-        opcode = istream[0].toInt()
+        try {
+            opcode = istream[0].toInt()
+        } catch(_: IndexOutOfBoundsException) {
+            return fmt("????")
+        }
 
         vpc = 1
         try {

src/main/kotlin/com/thequux/mcpdp/debug/FlightRecorder.kt

@@ -0,0 +1,26 @@
+package com.thequux.mcpdp.debug
+
+import java.io.PrintStream
+import java.io.Writer
+
+@OptIn(ExperimentalUnsignedTypes::class)
+class FlightRecorder(size: Int): Collector {
+    var trace: Array<TraceRecord?> = Array(size) { null }
+    var pos = 0
+
+    override fun invoke(record: TraceRecord) {
+        trace[pos++] = record
+        if (pos >= trace.size) pos -= trace.size
+    }
+
+    fun dump(os: PrintStream) {
+        val dis = Disassembler()
+        for (i in trace.indices) {
+            val i0 = (i + pos) % trace.size
+            val record = trace[i0]
+            if (record != null) {
+                os.println(record.report(dis))
+            }
+        }
+    }
+}