Implement svcGetCurrentProcessorNumber

include/kernel/kernel.hpp

@@ -61,7 +61,7 @@ class Kernel {
 	Handle makeProcess(u32 id);
 	Handle makePort(const char* name);
 	Handle makeSession(Handle port);
-	Handle makeThread(u32 entrypoint, u32 initialSP, u32 priority, s32 id, u32 arg,ThreadStatus status = ThreadStatus::Dormant);
+	Handle makeThread(u32 entrypoint, u32 initialSP, u32 priority, ProcessorID id, u32 arg,ThreadStatus status = ThreadStatus::Dormant);
 	Handle makeMemoryBlock(u32 addr, u32 size, u32 myPermission, u32 otherPermission);
 
 public:
@@ -126,6 +126,7 @@ private:
 	void exitThread();
 	void mapMemoryBlock();
 	void queryMemory();
+	void getCurrentProcessorNumber();
 	void getProcessID();
 	void getProcessInfo();
 	void getResourceLimit();

include/kernel/kernel_types.hpp

@@ -34,6 +34,16 @@ enum class ArbitrationType {
     DecrementAndWaitIfLessTimeout = 4
 };
 
+enum class ProcessorID : s32 {
+    AllCPUs = -1,
+    Default = -2,
+    
+    AppCore = 0,
+    Syscore = 1,
+    New3DSExtra1 = 2,
+    New3DSExtra2 = 3
+};
+
 struct AddressArbiter {};
 
 struct ResourceLimits {
@@ -95,7 +105,7 @@ struct Thread {
     u32 entrypoint; // Initial r15 value
     u32 priority;
     u32 arg;
-    s32 processorID;
+    ProcessorID processorID;
     ThreadStatus status;
     Handle handle;  // OS handle for this thread
     int index; // Index of the thread. 0 for the first thread, 1 for the second, and so on

src/core/kernel/kernel.cpp

@@ -35,6 +35,7 @@ void Kernel::serviceSVC(u32 svc) {
 		case 0x0A: svcSleepThread(); break;
 		case 0x0B: getThreadPriority(); break;
 		case 0x0C: setThreadPriority(); break;
+		case 0x11: getCurrentProcessorNumber(); break;
 		case 0x13: svcCreateMutex(); break;
 		case 0x14: svcReleaseMutex(); break;
 		case 0x15: svcCreateSemaphore(); break;
@@ -158,7 +159,7 @@ void Kernel::reset() {
 	// Make main thread object. We do not have to set the entrypoint and SP for it as the ROM loader does.
 	// Main thread seems to have a priority of 0x30. TODO: This creates a dummy context for thread 0,
 	// which is thankfully not used. Maybe we should prevent this
-	mainThread = makeThread(0, VirtualAddrs::StackTop, 0x30, -2, 0, ThreadStatus::Running);
+	mainThread = makeThread(0, VirtualAddrs::StackTop, 0x30, ProcessorID::Default, 0, ThreadStatus::Running);
 	currentThreadIndex = 0;
 	setupIdleThread();
 

src/core/kernel/threads.cpp

@@ -106,7 +106,7 @@ void Kernel::rescheduleThreads() {
 }
 
 // Internal OS function to spawn a thread
-Handle Kernel::makeThread(u32 entrypoint, u32 initialSP, u32 priority, s32 id, u32 arg, ThreadStatus status) {
+Handle Kernel::makeThread(u32 entrypoint, u32 initialSP, u32 priority, ProcessorID id, u32 arg, ThreadStatus status) {
 	int index; // Index of the created thread in the  threads array
 
 	if (threadCount < appResourceLimits.maxThreads) [[likely]] { // If we have not yet created over too many threads
@@ -389,8 +389,14 @@ void Kernel::createThread() {
 		return;
 	}
 
+	if (id < -2 && id > 3) {
+		Helpers::warn("Invalid processor ID in CreateThread");
+		// TODO: This should return an error
+		id = static_cast<s32>(ProcessorID::AppCore);
+	}
+
 	regs[0] = Result::Success;
-	regs[1] = makeThread(entrypoint, initialSP, priority, id, arg, ThreadStatus::Ready);
+	regs[1] = makeThread(entrypoint, initialSP, priority, static_cast<ProcessorID>(id), arg, ThreadStatus::Ready);
 	requireReschedule();
 }
 
@@ -468,6 +474,31 @@ void Kernel::setThreadPriority() {
 	requireReschedule();
 }
 
+void Kernel::getCurrentProcessorNumber() {
+	const ProcessorID id = threads[currentThreadIndex].processorID;
+	s32 ret;
+
+	// Until we properly implement per-core schedulers, return whatever processor ID passed to svcCreateThread
+	switch (id) {
+		case ProcessorID::Default:
+			ret = static_cast<s32>(ProcessorID::AppCore);
+			break;
+
+		case ProcessorID::AllCPUs:
+			ret = static_cast<s32>(ProcessorID::AppCore);
+			Helpers::warn("GetCurrentProcessorNumber on thread created to run on all CPUs...?\n");
+			break;
+
+		default: ret = static_cast<s32>(id); break;
+	}
+
+	if (ret != static_cast<s32>(ProcessorID::AppCore)) {
+		Helpers::warn("GetCurrentProcessorNumber: Thread not running on appcore\n");
+	}
+
+	regs[0] = ret;
+}
+
 void Kernel::exitThread() {
 	logSVC("ExitThread\n");