Setup ARM for execution.

src/emucore/CartELF.cxx

@@ -189,8 +189,6 @@ CartridgeELF::CartridgeELF(const ByteBuffer& image, size_t size, string_view md5
 
   parseAndLinkElf();
   setupMemoryMap();
-
-  reset();
 }
 
 
@@ -230,6 +228,8 @@ void CartridgeELF::reset()
   myVcsLib.vcsStartOverblank();
   myVcsLib.vcsEndOverblank();
   myVcsLib.vcsNop2n(1024);
+
+  jumpToMain();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -277,6 +277,11 @@ bool CartridgeELF::poke(uInt16 address, uInt8 value)
   return false;
 }
 
+void CartridgeELF::consoleChanged(ConsoleTiming timing)
+{
+  myConsoleTiming = timing;
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 const ByteBuffer& CartridgeELF::getImage(size_t& size) const
 {
@@ -284,6 +289,7 @@ const ByteBuffer& CartridgeELF::getImage(size_t& size) const
   return myImage;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt8 CartridgeELF::overdrivePeek(uInt16 address, uInt8 value)
 {
   value = driveBus(address, value);
@@ -296,11 +302,13 @@ uInt8 CartridgeELF::overdrivePeek(uInt16 address, uInt8 value)
   return value;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt8 CartridgeELF::overdrivePoke(uInt16 address, uInt8 value)
 {
   return driveBus(address, value);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 inline uInt8 CartridgeELF::driveBus(uInt16 address, uInt8 value)
 {
   auto* nextTransaction = myTransactionQueue.getNextTransaction(address);
@@ -311,6 +319,7 @@ inline uInt8 CartridgeELF::driveBus(uInt16 address, uInt8 value)
   return value;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void CartridgeELF::parseAndLinkElf()
 {
   ElfParser elfParser;
@@ -359,6 +368,7 @@ void CartridgeELF::parseAndLinkElf()
   #endif
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void CartridgeELF::setupMemoryMap()
 {
   mySectionStack = make_unique<uInt8[]>(STACK_SIZE);
@@ -382,4 +392,63 @@ void CartridgeELF::setupMemoryMap()
                        STUB_SIZE / CortexM0::PAGE_SIZE, true, &myVcsLib);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt32 CartridgeELF::getCoreClock() const
+{
+  switch (myConsoleTiming) {
+    case ConsoleTiming::ntsc:
+      return myArmCyclesPer6502Cycle * 262 * 76 * 60;
+
+    case ConsoleTiming::pal:
+    case ConsoleTiming::secam:
+      return myArmCyclesPer6502Cycle * 312 * 76 * 50;
+
+    default:
+      throw runtime_error("invalid console timing");
+  }
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt32 CartridgeELF::getSystemType() const
+{
+  switch (myConsoleTiming) {
+    case ConsoleTiming::ntsc:
+      return ST_NTSC_2600;
+
+    // Use frame layout here instead
+    case ConsoleTiming::pal:
+    case ConsoleTiming::secam:
+      return ST_PAL_2600;
+
+    default:
+      throw runtime_error("invalid console timing");
+  }
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void CartridgeELF::jumpToMain()
+{
+  if (!mySystem) throw runtime_error("cartridge not installed");
+
+  uInt32 sp = ADDR_STACK_BASE + STACK_SIZE;
+  CortexM0::err_t err = 0;
+
+  // Feature flags
+  sp -= 4;
+  err |= myCortexEmu.write32(sp, 0);
+
+  sp -= 4;
+  err |= myCortexEmu.write32(sp, getCoreClock());
+
+  sp -= 4;
+  err |= myCortexEmu.write32(sp, getSystemType());
+
+  if (err) throw runtime_error("unable to setup main args");
+
+  myCortexEmu
+    .setRegister(0, sp )
+    .setRegister(14, RETURN_ADDR_MAIN)
+    .setRegister(15, myArmEntrypoint);
+}
+
 

src/emucore/CartELF.hxx

@@ -47,6 +47,8 @@ class CartridgeELF: public Cartridge {
 
     bool poke(uInt16 address, uInt8 value) override;
 
+    void consoleChanged(ConsoleTiming timing) override;
+
   // Methods from Cartridge
   public:
     bool bankChanged() override { return false; }
@@ -66,10 +68,13 @@ class CartridgeELF: public Cartridge {
   private:
     uInt8 driveBus(uInt16 address, uInt8 value);
 
-  private:
     void parseAndLinkElf();
     void setupMemoryMap();
 
+    uInt32 getCoreClock() const;
+    uInt32 getSystemType() const;
+    void jumpToMain();
+
   private:
     ByteBuffer myImage;
     size_t myImageSize{0};
@@ -94,6 +99,9 @@ class CartridgeELF: public Cartridge {
     unique_ptr<uInt8[]> mySectionTables;
 
     VcsLib myVcsLib;
+
+    ConsoleTiming myConsoleTiming{ConsoleTiming::ntsc};
+    uInt32 myArmCyclesPer6502Cycle{80};
 };
 
 #endif // CARTRIDGE_ELF

src/emucore/CortexM0.hxx

@@ -105,6 +105,14 @@ class CortexM0
 
     err_t run(uInt32 maxCycles, uInt32& cycles);
 
+    err_t read32(uInt32 address, uInt32& value);
+    err_t read16(uInt32 address, uInt16& value);
+    err_t read8(uInt32 address, uInt8& value);
+
+    err_t write32(uInt32 address, uInt32 value);
+    err_t write16(uInt32 address, uInt16 value);
+    err_t write8(uInt32 address, uInt8 value);
+
   private:
 
     enum class MemoryRegionType : uInt8 {
@@ -154,14 +162,6 @@ class CortexM0
     MemoryRegion& setupMapping(uInt32 pageBase, uInt32 pageCount,
                                bool readOnly, MemoryRegionType type);
 
-    err_t read32(uInt32 address, uInt32& value);
-    err_t read16(uInt32 address, uInt16& value);
-    err_t read8(uInt32 address, uInt8& value);
-
-    err_t write32(uInt32 address, uInt32 value);
-    err_t write16(uInt32 address, uInt16 value);
-    err_t write8(uInt32 address, uInt8 value);
-
     err_t fetch16(uInt32 address, uInt16& value, uInt8& op);
 
     void do_cvflag(uInt32 a, uInt32 b, uInt32 c);

src/emucore/elf/ElfEnvironment.hxx

@@ -106,6 +106,12 @@ namespace elfEnvironment {
   extern const uInt8 OVERBLANK_PROGRAM[];
   extern const uInt32 OVERBLANK_PROGRAM_SIZE;
 
+  constexpr uInt32  ST_NTSC_2600 =	0;
+  constexpr uInt32  ST_PAL_2600 = 1;
+  constexpr uInt32  ST_PAL60_2600 = 2;
+
+  constexpr uInt32 RETURN_ADDR_MAIN = 0xffffdead;
+
   enum class Palette: uInt8 {pal, ntsc};
 
   vector<ElfLinker::ExternalSymbol> externalSymbols(Palette palette);

src/emucore/elf/VcsLib.cxx

@@ -55,6 +55,7 @@ void VcsLib::vcsStartOverblank()
     .yield(0x0080);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void VcsLib::vcsEndOverblank()
 {
   myTransactionQueue
@@ -63,6 +64,7 @@ void VcsLib::vcsEndOverblank()
     .setNextInjectAddress(0x1000);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void VcsLib::vcsNop2n(uInt16 n)
 {
   if (n == 0) return;