RtlImageXexHeaderField stub.

include/xenia/byte_order.h

@@ -64,5 +64,14 @@
 #define XEGETINT64LE(p)                 ( (int64_t)XESWAP64LE(*(uint64_t*)(p)))
 #define XEGETUINT64LE(p)                ((uint64_t)XESWAP64LE(*(uint64_t*)(p)))
 
+#define XESETINT8BE(p, v)               (*(  (int8_t*)(p)) = (int8_t)v)
+#define XESETUINT8BE(p, v)              (*( (uint8_t*)(p)) = (uint8_t)v)
+#define XESETINT16BE(p, v)              (*( (int16_t*)(p)) = XESWAP16BE( (int16_t)v))
+#define XESETUINT16BE(p, v)             (*((uint16_t*)(p)) = XESWAP16BE((uint16_t)v))
+#define XESETINT32BE(p, v)              (*( (int32_t*)(p)) = XESWAP32BE( (int32_t)v))
+#define XESETUINT32BE(p, v)             (*((uint32_t*)(p)) = XESWAP32BE((uint32_t)v))
+#define XESETINT64BE(p, v)              (*( (int64_t*)(p)) = XESWAP64BE( (int64_t)v))
+#define XESETUINT64BE(p, v)             (*((uint64_t*)(p)) = XESWAP64BE((uint64_t)v))
+
 
 #endif  // XENIA_BYTE_ORDER_H_

src/kernel/modules/xboxkrnl/xboxkrnl_module.cc

@@ -67,6 +67,8 @@ XboxkrnlModule::XboxkrnlModule(xe_pal_ref pal, xe_memory_ref memory,
   // TODO(benvanik): alloc heap memory somewhere in user space
   // TODO(benvanik): tools for reading/writing to heap memory
 
+  uint8_t* mem = xe_memory_addr(memory, 0);
+
   // HACK: register some dummy globals for now.
   // KeDebugMonitorData
   resolver->SetVariableMapping(
@@ -76,12 +78,21 @@ XboxkrnlModule::XboxkrnlModule(xe_pal_ref pal, xe_memory_ref memory,
   resolver->SetVariableMapping(
       "xboxkrnl.exe", 0x00000156,
       0x40002000);
+
   // XexExecutableModuleHandle
+  // Games try to dereference this to get a pointer to some module struct.
+  // So far it seems like it's just in loader code, and only used to look up
+  // the XexHeaderBase for use by RtlImageXexHeaderField.
+  // We fake it so that the address passed to that looks legit.
+  // 0x80100FFC <- pointer to structure
+  // 0x80101000 <- our module structure
+  // 0x80101058 <- pointer to xex header
+  // 0x80101100 <- xex header base
   resolver->SetVariableMapping(
       "xboxkrnl.exe", 0x00000193,
-      0x40000000);
-
-  // 0x0000012B, RtlImageXexHeaderField
+      0x80100FFC);
+  XESETUINT32BE(mem + 0x80100FFC, 0x80101000);
+  XESETUINT32BE(mem + 0x80101058, 0x80101100);
 }
 
 XboxkrnlModule::~XboxkrnlModule() {

src/kernel/modules/xboxkrnl/xboxkrnl_rtl.cc

@@ -9,6 +9,8 @@
 
 #include "kernel/modules/xboxkrnl/xboxkrnl_rtl.h"
 
+#include <xenia/kernel/xex2.h>
+
 #include "kernel/shim_utils.h"
 #include "kernel/modules/xboxkrnl/xboxkrnl.h"
 
@@ -21,6 +23,50 @@ using namespace xe::kernel::xboxkrnl;
 namespace {
 
 
+void RtlImageXexHeaderField_shim(
+    xe_ppc_state_t* ppc_state, KernelState* state) {
+  // PVOID
+  // PVOID XexHeaderBase
+  // DWORD ImageField
+
+  uint32_t xex_header_base    = SHIM_GET_ARG_32(0);
+  uint32_t image_field        = SHIM_GET_ARG_32(1);
+
+  // NOTE: this is totally faked!
+  // We set the XexExecutableModuleHandle pointer to a block that has at offset
+  // 0x58 a pointer to our XexHeaderBase. If the value passed doesn't match
+  // then die.
+  // The only ImageField I've seen in the wild is
+  // 0x20401 (XEX_HEADER_DEFAULT_HEAP_SIZE), so that's all we'll support.
+
+  XELOGD(
+      XT("RtlImageXexHeaderField(%.8X, %.8X)"),
+      xex_header_base, image_field);
+
+  if (xex_header_base != 0x80101100) {
+    XELOGE(XT("RtlImageXexHeaderField with non-magic base NOT IMPLEMENTED"));
+    SHIM_SET_RETURN(0);
+    return;
+  }
+
+  uint32_t return_value = 0;
+  switch (image_field) {
+    case XEX_HEADER_DEFAULT_HEAP_SIZE:
+      // TODO(benvanik): pull from running module
+      // This is header->exe_heap_size.
+      return_value = 0;
+      break;
+    default:
+      XELOGE(XT("RtlImageXexHeaderField header field %.8X NOT IMPLEMENTED"),
+             image_field);
+      SHIM_SET_RETURN(0);
+      return;
+  }
+
+  SHIM_SET_RETURN(return_value);
+}
+
+
 }
 
 
@@ -30,5 +76,7 @@ void xe::kernel::xboxkrnl::RegisterRtlExports(
     export_resolver->SetFunctionMapping("xboxkrnl.exe", ordinal, \
         state, (xe_kernel_export_shim_fn)shim, (xe_kernel_export_impl_fn)impl)
 
+  SHIM_SET_MAPPING(0x0000012B, RtlImageXexHeaderField_shim, NULL);
+
   #undef SET_MAPPING
 }