From efa0a8bb395a16d2457b8d07d8d50951ad12a873 Mon Sep 17 00:00:00 2001
From: Gliniak <Gliniak93@gmail.com>
Date: Sat, 1 Nov 2025 00:13:08 +0100
Subject: [PATCH] [XBDM] Added sketchy implementation of DmPMCGetCounterName
 and DmPMCInstallAndStart

---
 src/xenia/kernel/kernel_state.cc   | 44 ++++++++++++++++++++++++++++++
 src/xenia/kernel/kernel_state.h    |  3 ++
 src/xenia/kernel/xbdm/xbdm_misc.cc | 17 ++++++++++++
 src/xenia/kernel/xbdm/xbdm_misc.h  |  1 +
 4 files changed, 65 insertions(+)

diff --git a/src/xenia/kernel/kernel_state.cc b/src/xenia/kernel/kernel_state.cc
index 03b89580f..b073df207 100644
--- a/src/xenia/kernel/kernel_state.cc
+++ b/src/xenia/kernel/kernel_state.cc
@@ -1523,5 +1523,49 @@ void KernelState::InitializeKernelGuestGlobals() {
            offsetof32(KernelGuestGlobals, IoDeviceObjectType)}};
   xboxkrnl::xeKeSetEvent(&block->UsbdBootEnumerationDoneEvent, 1, 0);
 }
+
+void KernelState::InitializeXbdmCpuCounters() {
+  constexpr uint32_t counters_base_address = 0x91F00000;
+
+  // These are not confirmed and there seems to be multiple types of counters,
+  // but no idea how they're switched. For now this seems to be good enough.
+  constexpr std::array<const char*, 0x11> xbdm_counters = {
+      "load-hit-stores (S)",
+      "instructions committed",
+      "i-cache miss cycles",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "core 0 L2 data misses",
+      "Bad counter number - must be 0-15."};
+
+  auto xbdm_range = memory_->LookupHeap(counters_base_address);
+  if (!xbdm_range->AllocFixed(
+          counters_base_address, 0x1000, 0,
+          kMemoryAllocationCommit | kMemoryAllocationReserve,
+          kMemoryProtectRead | kMemoryProtectWrite)) {
+    return;
+  }
+
+  uint32_t address = counters_base_address;
+
+  for (size_t i = 0; i < xbdm_counters.size(); i++) {
+    xbdm_counters_address[i] = address;
+    const std::string entry = xbdm_counters[i];
+    std::memcpy(memory_->TranslateVirtual<char*>(address), entry.c_str(),
+                entry.size());
+    address += static_cast<uint32_t>(entry.size()) + 1;
+  }
+}
+
 }  // namespace kernel
 }  // namespace xe
diff --git a/src/xenia/kernel/kernel_state.h b/src/xenia/kernel/kernel_state.h
index b6ee873ac..8095c3fa7 100644
--- a/src/xenia/kernel/kernel_state.h
+++ b/src/xenia/kernel/kernel_state.h
@@ -323,6 +323,9 @@ class KernelState {
                              uint32_t interrupt_callback_data, uint32_t source,
                              uint32_t cpu);
 
+  void InitializeXbdmCpuCounters();
+  std::array<uint32_t, 0x11> xbdm_counters_address = {};
+
  private:
   void LoadKernelModule(object_ref<KernelModule> kernel_module);
   void InitializeProcess(X_KPROCESS* process, uint32_t type, char unk_18,
diff --git a/src/xenia/kernel/xbdm/xbdm_misc.cc b/src/xenia/kernel/xbdm/xbdm_misc.cc
index 91dba8550..58c837896 100644
--- a/src/xenia/kernel/xbdm/xbdm_misc.cc
+++ b/src/xenia/kernel/xbdm/xbdm_misc.cc
@@ -468,6 +468,23 @@ DECLARE_XBDM_EXPORT1(DmSetDumpMode, kDebug, kStub);
 dword_result_t DmIsFastCAPEnabled_entry() { return XBDM_UNSUCCESSFUL; }
 DECLARE_XBDM_EXPORT1(DmIsFastCAPEnabled, kDebug, kStub);
 
+dword_result_t DmPMCInstallAndStart_entry(dword_t group_setup) {
+  // Not initialized, so let's initialize it
+  if (kernel_state()->xbdm_counters_address[0] == 0) {
+    kernel_state()->InitializeXbdmCpuCounters();
+  }
+  return XBDM_SUCCESSFUL;
+}
+DECLARE_XBDM_EXPORT1(DmPMCInstallAndStart, kDebug, kSketchy);
+
+dword_result_t DmPMCGetCounterName_entry(dword_t counter_id) {
+  // This returns pointer to already preallocated string with counter names.
+  // We should make allocation somewhere during xbdm initialization once
+  return kernel_state()->xbdm_counters_address
+      [counter_id < 0x10 ? static_cast<uint32_t>(counter_id) : 0x10];
+}
+DECLARE_XBDM_EXPORT1(DmPMCGetCounterName, kDebug, kSketchy);
+
 void __CAP_Start_Profiling_entry(dword_t a1, dword_t a2) {}
 
 DECLARE_XBDM_EXPORT1(__CAP_Start_Profiling, kDebug, kStub);
diff --git a/src/xenia/kernel/xbdm/xbdm_misc.h b/src/xenia/kernel/xbdm/xbdm_misc.h
index eaa639f79..2abca5de7 100644
--- a/src/xenia/kernel/xbdm/xbdm_misc.h
+++ b/src/xenia/kernel/xbdm/xbdm_misc.h
@@ -26,6 +26,7 @@ static constexpr char DmXboxName[] = "Xbox360Name";
 #define XBDM_UNSUCCESSFUL       0x82DA0000
 #define XBDM_FASTCAPENABLED     0x82DA0007
 #define XBDM_ALREADYEXISTS      0x82DA0010
+#define XBDM_UNKNOWNFAILURE     0x82DA002C
 #define XBDM_ENDOFLIST          0x82DA0104
 #define XBDM_BUFFER_TOO_SMALL   0x82DA0105