Delink/begin decompiling entry point

That is, xapi0.obj, which has been renamed from crt0.obj because it
appears to be part of the Xbox libraries rather than the C runtime.

decompile/objdiff.json

@@ -14,10 +14,10 @@
         "source_path": "src/JSRF/Jet2.cpp"
       },
       "symbol_mappings": {
-        "?main_funcinfo@@3UFuncInfo@@A": "$T745",
+        "?main_funcinfo@@3UFuncInfo@@A": "$T747",
-        "?main_handler@@YAXPAUEHExceptionRecord@@PAKPAXPAU_xDISPATCHER_CONTEXT@@@Z": "$L749",
+        "?main_handler@@YAXPAUEHExceptionRecord@@PAKPAXPAU_xDISPATCHER_CONTEXT@@@Z": "$L751",
-        "?main_handler_unwind1@@YAXXZ": "$L741",
+        "?main_handler_unwind1@@YAXXZ": "$L743",
-        "?main_unwindmap@@3PAUUnwindMapEntry@@A": "$T751",
+        "?main_unwindmap@@3PAUUnwindMapEntry@@A": "$T753",
         "[.rdata-0]": "[.xdata$x-0]"
       }
     },
@@ -42,6 +42,15 @@
         "?finalizeGameData@@YAXXZ": "_$E2",
         "?initGameData@@YAXXZ": "_$E1"
       }
+    },
+    {
+      "name": "XDK/Xapi/xapi0",
+      "target_path": "target/XDK/Xapi/xapi0.obj",
+      "base_path": "src/XDK/Xapi/xapi0.obj",
+      "metadata": {
+        "complete": false,
+        "source_path": "src/XDK/Xapi/xapi0.c"
+      }
     }
   ]
 }

decompile/src/XDK/CRT/crt0.c

@@ -1,33 +0,0 @@
-/* JSRF Decompilation: XDK/CRT0.c
-C runtime initialization.
-Like other CRT code, there's some magic here with symbols that get special
-treatment from the compiler and linker.
-*/
-
-#include "../Win32.h"
-
-
-// Every program is supposed to have a main(), so we can just assume its
-// existence with a declaration here
-int main(void);
-
-
-void  __cdecl   mainCRTStartup (void);
-DWORD __stdcall mainXapiStartup(LPVOID lpThreadParameter);
-
-
-// Address: 0x00148023
-// Status: unimplemented
-void __cdecl mainCRTStartup(void) {
-/* The true entrypoint of the game, spawning a thread for the rest to run in
-The linker automatically sets this function to the entrypoint.
-*/
-}
-
-// Address: 0x00147FB4
-// Status: unimplemented
-DWORD __stdcall mainXapiStartup(LPVOID const lpThreadParameter) {
-/* Runs some initialization and then calls main() */
-	main();
-	return 0;
-}

decompile/src/XDK/Win32.h

@@ -25,7 +25,7 @@ typedef          __int64  LONGLONG;
 
 typedef unsigned char  BYTE;
 typedef unsigned short WORD;
-typedef unsigned long  DWORD;
+typedef unsigned long  DWORD, * PDWORD;
 
 typedef void            VOID;
 typedef void          * LPVOID;
@@ -45,6 +45,8 @@ union LARGE_INTEGER {
     LONGLONG QuadPart;
 };
 
+typedef void * HANDLE;
+
 // Return codes
 typedef long HRESULT;
 

decompile/src/XDK/Xapi/xapi0.c

@@ -0,0 +1,83 @@
+/* JSRF Decompilation: XDK/Xapi/xapi0.c
+Entrypoint for Xbox programs.
+Awkwardly, the placement in the .xbe suggests this is not part of the C runtime
+(which is normally what provides mainCRTStartup()), but rather part of Xapi.
+It's been named xapi0 in analogy to crt0 in a C runtime.
+*/
+
+#include "../CRT/stddef.h"
+#include "../Win32.h"
+
+
+// Things that should get declared in a header somewhere
+#define XLD_LAUNCH_DASHBOARD_ERROR 1
+#define XLD_ERROR_INVALID_XBE      1
+
+extern struct IMAGE_TLS_DIRECTORY {
+	DWORD   StartAddressOfRawData;
+	DWORD   EndAddressOfRawData;
+	DWORD * AddressOfIndex;
+	void  * AddressOfCallbacks;
+	DWORD   SizeOfZeroFill;
+	DWORD   Characteristics;
+} _tls_used;
+
+extern int XapiTlsSize;
+
+DWORD __stdcall mainXapiStartup(LPVOID lpThreadParameter);
+BOOL  __stdcall CloseHandle    (HANDLE hHandle          );
+
+typedef DWORD (__stdcall * LPTHREAD_START_ROUTINE)(LPVOID lpThreadParameter);
+HANDLE __stdcall CreateThread(
+	void *                 lpThreadAttributes,
+	DWORD                  dwStackSize,
+	LPTHREAD_START_ROUTINE lpStartAddress,
+	LPVOID                 lpParameter,
+	DWORD                  dwCreationFlags,
+	PDWORD                 lpThreadId
+);
+
+void __stdcall XapiBootToDash(
+	DWORD dwReason,
+	DWORD dwParameter1,
+	DWORD dwParameter2
+);
+
+
+// Every program is supposed to have a main(), so we can just assume its
+// existence with a declaration here
+int main(void);
+
+
+// Address: 0x00147FB4
+// Status: unimplemented
+DWORD __stdcall mainXapiStartup(LPVOID lpThreadParameter) {
+/* Runs some Xbox-specific initialization and then calls main() */
+	main();
+	return 0;
+}
+
+// Address: 0x00148023
+// Status: nonmatching
+void mainCRTStartup(void) {
+/* The true entrypoint of the game, spawning a thread for the rest to run in
+The linker automatically sets this function to the entrypoint.
+*/
+	HANDLE thread;
+
+	// Figure out available thread-local storage
+	XapiTlsSize = (
+		(_tls_used.EndAddressOfRawData - _tls_used.StartAddressOfRawData) +
+		_tls_used.SizeOfZeroFill
+	) + 15 & 0xFFFFFFF0; // Round up to nearest 0x10
+	*_tls_used.AddressOfIndex = XapiTlsSize / (-4);
+
+	// Launch program as a thread
+	thread = CreateThread(NULL, 0, mainXapiStartup, NULL, 0, NULL);
+
+	// Boot back to dashboard with an error message if launching failed
+	if (thread == NULL)
+		XapiBootToDash(XLD_LAUNCH_DASHBOARD_ERROR, XLD_ERROR_INVALID_XBE, 0);
+
+	CloseHandle(thread);
+}

ghidra/objects.csv

@@ -3,13 +3,14 @@ JSRF/Core.obj,true,0x00011000-0x00013FEB,,,0x00186BA0-0x00186C14,,,,,,0x001C4390
 JSRF/GameData.obj,true,0x00039B50-0x0003B937,0x0018AD60-0x0018AD75,0x0018C9A0-0x0018C9AA,,,,,,,0x001CA16C-0x001CA3DB,,0x001EB790-0x001EB793,0x001EFC88-0x001F7047,
 JSRF/Jet2.obj,true,0x0006F9E0-0x0006FA6F,,,0x00187710-0x00187724,,,,,,,0x001E620C-0x001E622F,,0x0022FCE0-0x0022FCE3,
 ADX (need to decompose),false,0x0013A570-0x0014555F,?,?,?,?,,,,,,?,?,?,
-XDK Core (need to decompose),false,0x00145560-0x0014B79F,?,?,?,?,,,,,,?,?,?,
+Xapi (need to decompose),false,0x00145560-0x0014B79F,?,?,?,?,,,,,,?,?,?,
+XDK/Xapi/xapi0.obj,true,0x00147FB4-0x0014807C,,,,,,,,,,,,,
 Smilebit libs (need to decompose),false,0x0014B7A0-0x0017BF3F,?,?,?,?,,,,,,?,?,?-0x0022ED2B,
-C runtime,false,0x0017BF40-0x00182B80,?,?,?,,,,,?,?,0x0022ED2C-?,?,?,
+C runtime (need to decompose),false,0x0017BF40-0x00182B80,?,?,?,,,,,?,?,0x0022ED2C-?,?,?,
 Unknown MS math lib,false,0x00182B81-0x0018694F,?,?,?,,,,,?,?,?,?,?,
 Another (tiny) Smilebit math lib,false,0x00186950-0x00186B7F,?,?,?,,,,,?,?,?,?,?,
 Direct3D8 (need to decompose),false,,?,,0x0018CB40-0x0019E334,,,,,?,?,?,?,?,
 DirectSound8 (need to decompose),false,,?,?,,,0x0019E340-0x001BA89B,,,,?,?,?,?,0x0027E080-0x00284E17
-MMatrix.obj,false,,?,,,,0x001BA8A0-0x001BBAAF,,,,,?,?,0x00264BD8-0x00264C13,
+Smilebit/MMatrix.obj,false,,?,,,,0x001BA8A0-0x001BBAAF,,,,,?,?,0x00264BD8-0x00264C13,
 Xgraphics (need to decompose),false,,?,,,,,0x001BBAC0-0x001BC7BB,,,,?,?,,
 XDK Peripherals (need to decompose),false,,?,,,,,,0x001BC7C0-0x001C3F57,,,?,?,,