init

runtime/src/hle/esp.cpp

@@ -0,0 +1,118 @@
+// ESP HLE Stubs
+// ESP functions communicate with /dev/es to get title information.
+// We stub these to return Mario Kart Wii's title ID directly.
+
+#include "hle_stubs.h"
+#include "memory.h"
+#include "runtime_log.h"
+#include <cstring>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cctype>
+
+static constexpr uint32_t MKW_TITLE_ID_HI = 0x00010004;
+static constexpr uint32_t MKW_TITLE_ID_LO = 0x524D4350; // "RMCP" fallback
+
+static bool IsValidEspTitleCode(uint32_t code) {
+    for (int shift = 24; shift >= 0; shift -= 8) {
+        const char ch = static_cast<char>((code >> shift) & 0xffu);
+        if (!std::isalnum(static_cast<unsigned char>(ch))) {
+            return false;
+        }
+    }
+    return true;
+}
+
+static uint32_t CurrentTitleIdLo() {
+    if (Memory::Contains(0x80000000u, 4u)) {
+        const uint32_t code = Memory::Read32(0x80000000u);
+        if (IsValidEspTitleCode(code)) {
+            return code;
+        }
+    }
+
+    return MKW_TITLE_ID_LO;
+}
+
+// The guest asked for its title ID or data directory through a pointer we cannot
+// honour. Nothing downstream explains why the save-data path then fails, so say
+// so - once per site, because the caller may retry every frame.
+static void ReportEspArgError(bool& logged, const char* who, const char* what)
+{
+    if (logged) {
+        return;
+    }
+    logged = true;
+    RT_LOGF(RT_TAG_HLE, "%s: %s\n", who, what);
+    std::fflush(stderr);
+}
+
+// 0x801671d0 -> ESP_InitLib
+// Opens /dev/es. We just pretend it succeeded.
+extern "C" int32_t ESP_InitLib_stub(void)
+{
+    return 0;
+}
+PPC_NATIVE_OVERRIDE(801671d0, ESP_InitLib_stub, int32_t, (void), ());
+
+// 0x80167224 -> ESP_CloseLib  
+// Closes /dev/es. No-op for us.
+extern "C" int32_t ESP_CloseLib_stub(void)
+{
+    return 0;
+}
+PPC_NATIVE_OVERRIDE(80167224, ESP_CloseLib_stub, int32_t, (void), ());
+
+// 0x8016799c -> ESP_GetTitleId
+// Gets the 64-bit title ID. param_1 is pointer to 8 bytes.
+// Decompiled signature: int ESP_GetTitleId(undefined4 *param_1)
+extern "C" int32_t ESP_GetTitleId_stub(uint32_t outPtr)
+{
+    if (outPtr == 0) {
+        static bool logged = false;
+        ReportEspArgError(logged, "ESP_GetTitleId", "null output pointer, returning error");
+        return -0x3f9; // Same error as original for null
+    }
+
+    // Write title ID (big-endian)
+    Memory::Write32(outPtr, MKW_TITLE_ID_HI);
+    Memory::Write32(outPtr + 4, CurrentTitleIdLo());
+    return 0;
+}
+PPC_NATIVE_OVERRIDE(8016799c, ESP_GetTitleId_stub, int32_t, (uint32_t outPtr), (outPtr));
+
+// 0x80167904 -> ESP_GetDataDir(titleHi, titleLo, outPathPtr)
+// Gets the NAND data directory path for a title.
+extern "C" int32_t ESP_GetDataDir_stub(uint32_t titleHi, uint32_t titleLo, uint32_t outPathPtr)
+{
+    if (outPathPtr == 0) {
+        static bool loggedNull = false;
+        ReportEspArgError(loggedNull, "ESP_GetDataDir", "null output pointer, returning error");
+        return -0x3f9;
+    }
+
+    // Check alignment (original requires 32-byte alignment)
+    if ((outPathPtr & 0x1f) != 0) {
+        static bool loggedUnaligned = false;
+        ReportEspArgError(loggedUnaligned, "ESP_GetDataDir",
+                          "output pointer is not 32-byte aligned, returning error");
+        return -0x3f9;
+    }
+
+
+    // Build the path: /title/XXXXXXXX/YYYYYYYY/data
+    // This is what the game expects for its save data location
+    char path[64];
+    std::sprintf(path, "/title/%08x/%08x/data", titleHi, titleLo);
+    
+    // Copy path to game memory
+    const char* src = path;
+    uint32_t dst = outPathPtr;
+    while (*src) {
+        Memory::Write8(dst++, static_cast<uint8_t>(*src++));
+    }
+    Memory::Write8(dst, 0); // null terminator
+    return 0;
+}
+PPC_NATIVE_OVERRIDE(80167904, ESP_GetDataDir_stub, int32_t, (uint32_t titleHi, uint32_t titleLo, uint32_t outPathPtr), (titleHi, titleLo, outPathPtr));