make enough things work to boot EPOC32 successfully

diff --git a/WindCore/arm710t.cpp b/WindCore/arm710t.cpp
index db0c8f2ab4fb2a74c0c4284636d6eba6e227d2b4..324bb00a9deae48ad5bb29d7ce04c8e639facfdb 100644 (file)
--- a/WindCore/arm710t.cpp
+++ b/WindCore/arm710t.cpp
@@ -37,6 +37,7 @@ void ARM710T::switchBank(BankIndex newBank) {
 void ARM710T::switchMode(Mode newMode) {
        auto oldMode = currentMode();
        if (newMode != oldMode) {
+//             log("Switching mode! %x", newMode);
                switchBank(modeToBank[newMode & 0xF]);
 
                CPSR &= ~CPSR_ModeMask;
@@ -46,6 +47,7 @@ void ARM710T::switchMode(Mode newMode) {
 
 void ARM710T::raiseException(Mode mode, uint32_t savedPC, uint32_t newPC) {
        auto bankIndex = modeToBank[mode & 0xF];
+//     log("Raising exception mode %x, saving PC %08x, CPSR %08x", mode, savedPC, CPSR);
        SPSRs[bankIndex] = CPSR;
 
        switchMode(mode);
@@ -56,13 +58,14 @@ void ARM710T::raiseException(Mode mode, uint32_t savedPC, uint32_t newPC) {
 }
 
 void ARM710T::requestFIQ() {
-       raiseException(FIQ32, GPRs[15], 0x1C);
+       raiseException(FIQ32, getRealPC() + 4, 0x1C);
        CPSR |= CPSR_FIQDisable;
        CPSR |= CPSR_IRQDisable;
 }
 
 void ARM710T::requestIRQ() {
-       raiseException(FIQ32, GPRs[15], 0x18);
+//     log("Requesting IRQ: Last exec = %08x, setting LR = %08x", lastPcExecuted(), getRealPC() + 4);
+       raiseException(IRQ32, getRealPC() + 4, 0x18);
        CPSR |= CPSR_IRQDisable;
 }
 
@@ -92,14 +95,6 @@ uint32_t ARM710T::tick() {
 
        // fetch a new instruction
        auto newInsn = readVirtual(GPRs[15], V32);
-       if (GPRs[15] < 0x10 || GPRs[15] > 0xA0000000) {
-               log("HACK HACK HACK 2");
-               log("PC=%08x LR=%08x", GPRs[15], GPRs[14]);
-       }
-//     if (GPRs[15] == 0x50100000) {
-//             log("HACK HACK HACK");
-//             log("LR=%08x", GPRs[14]);
-//     }
        GPRs[15] += 4;
        prefetch[0] = newInsn.first.value_or(0);
        prefetchFaults[0] = newInsn.second;
@@ -109,10 +104,13 @@ uint32_t ARM710T::tick() {
        // now deal with the one we popped
        uint32_t clocks = 1;
        if (haveInsn) {
+               pcHistory[pcHistoryIndex] = {GPRs[15] - 0xC, insn};
+               pcHistoryIndex = (pcHistoryIndex + 1) % PcHistoryCount;
                if (insnFault != NoFault) {
                        // Raise a prefetch error
                        // These do not set FSR or FAR
                        log("prefetch error! %08x", insnFault >> MMUFaultAddressShift);
+                       logPcHistory();
                        raiseException(Abort32, GPRs[15] - 8, 0xC);
                } else {
                        clocks += executeInstruction(insn);
@@ -370,7 +368,7 @@ uint32_t ARM710T::execDataProcessing(bool I, uint32_t Opcode, bool S, uint32_t R
                                auto saved = SPSRs[currentBank()];
                                switchMode(modeFromCPSR(saved));
                                CPSR = saved;
-//                             log("dataproc restore CPSR: %08x", CPSR);
+//                             log("dataproc restore CPSR: %08x", saved);
                        }
                } else if (S) {
                        CPSR = (CPSR & ~CPSR_FlagMask) | flags;
@@ -562,17 +560,24 @@ uint32_t ARM710T::execBlockDataTransfer(uint32_t PUSWL, uint32_t Rn, uint32_t re
                }
        }
 
-       if (registerList & 0x8000)
-               prefetchCount = 0;
-
        // datasheet specifies that base register must be
        // restored if an error occurs during LDM
        if (load && fault != NoFault)
                GPRs[Rn] = writeback ? updatedBase : base;
 
-       if (psrForceUser && (!load || !(registerList & 0x8000)))
+       if (psrForceUser && (store || !(registerList & 0x8000)))
                switchBank(saveBank);
 
+       if (load && (registerList & 0x8000)) {
+               prefetchCount = 0;
+               if (psrForceUser && isPrivileged() && fault == NoFault) {
+                       auto saved = SPSRs[currentBank()];
+                       switchMode(modeFromCPSR(saved));
+                       CPSR = saved;
+//                     log("reloading saved SPSR: %08x", saved);
+               }
+       }
+
        if (fault != NoFault)
                reportFault(fault);
 
@@ -1046,13 +1051,9 @@ void ARM710T::log(const char *format, ...) {
        }
 }
 
-
-void ARM710T::test() {
-       uint64_t result;
-       uint32_t flags = 0;
-       uint32_t v = 0x10000000;
-
-       SUB_OP(v, v, 1);
-
-       log("RESULT:%llx FLAGS:%08x", result, flags);
+void ARM710T::logPcHistory() {
+       for (int i = 0; i < PcHistoryCount; i++) {
+               pcHistoryIndex = (pcHistoryIndex + 1) % PcHistoryCount;
+               log("%03d: %08x %08x", i, pcHistory[pcHistoryIndex].addr, pcHistory[pcHistoryIndex].insn);
+       }
 }

diff --git a/WindCore/arm710t.h b/WindCore/arm710t.h
index 2ce7f25f84f9eb8a4607f530c0696d43b2bf3553..009cdbd5c32daaa11083d2b619a2044338b7b3ba 100644 (file)
--- a/WindCore/arm710t.h
+++ b/WindCore/arm710t.h
@@ -21,8 +21,6 @@ typedef optional<uint32_t> MaybeU32;
 class ARM710T
 {
 public:
-       void test();
-
        enum ValueSize { V8 = 0, V32 = 1 };
 
        enum MMUFault : uint64_t {
@@ -106,13 +104,22 @@ public:
 
        uint32_t getGPR(int index) const { return GPRs[index]; }
        uint32_t getCPSR() const { return CPSR; }
+       uint32_t getRealPC() const {
+               return GPRs[15] - (4 * prefetchCount);
+       }
 
        void setLogger(std::function<void(const char *)> newLogger) { logger = newLogger; }
+       uint32_t lastPcExecuted() const { return pcHistory[(pcHistoryIndex - 1) % PcHistoryCount].addr; }
 protected:
        void log(const char *format, ...);
+       void logPcHistory();
 private:
        std::function<void(const char *)> logger;
 
+       enum { PcHistoryCount = 10 };
+       struct { uint32_t addr, insn; } pcHistory[PcHistoryCount];
+       uint32_t pcHistoryIndex = 0;
+
        enum { Nop = 0xE1A00000 };
 
        enum Mode : uint8_t {

diff --git a/WindCore/emu.cpp b/WindCore/emu.cpp
index fbac14f1a1a893deec8c47f6d5a264b59597126d..7fb0583a26e5de2fc392ec93efcbd83e1e24839f 100644 (file)
--- a/WindCore/emu.cpp
+++ b/WindCore/emu.cpp
@@ -315,6 +315,8 @@ void Emu::configure() {
        if (configured) return;
        configured = true;
 
+       srand(1000);
+
        uart1.cpu = this;
        uart2.cpu = this;
        memset(&tc1, 0, sizeof(tc1));
@@ -377,6 +379,11 @@ void Emu::executeUntil(int64_t cycles) {
                                log("⚠️ Breakpoint triggered at %08x!", new_pc);
                                return;
                        }
+                       if (new_pc >= 0x80000000 && new_pc <= 0x90000000) {
+                               log("BAD PC %08x!!", new_pc);
+                               logPcHistory();
+                               return;
+                       }
                }
        }
 }

diff --git a/WindQt/mainwindow.cpp b/WindQt/mainwindow.cpp
index 4472194c8e1b9a148cab41254e6c28af6516f245..b9c4fe31565a00da62ea235ce9e28936e66fe9f0 100644 (file)
--- a/WindQt/mainwindow.cpp
+++ b/WindQt/mainwindow.cpp
@@ -17,7 +17,6 @@ MainWindow::MainWindow(QWidget *parent) :
        emu->setLogger([&](const char *str) {
                ui->logView->appendPlainText(str);
        });
-       emu->test();
 
     timer = new QTimer(this);
     timer->setInterval(1000/64);