From 74c95c64d26d1e66fb5bbb042fa8b80bdf1e46f3 Mon Sep 17 00:00:00 2001
From: gibbed <rick@gibbed.us>
Date: Sat, 24 Aug 2019 09:48:27 -0500
Subject: [PATCH] [Kernel] Ignore page size with base addr allocs.

Changes NtAllocateVirtualMemory so that it ignores specified page size when a
base address is specified.

Fixes a crash seen in N3 demo boot.
---
 src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc b/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc
index 31061a697..7a384bcc2 100644
--- a/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc
+++ b/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc
@@ -96,10 +96,17 @@ dword_result_t NtAllocateVirtualMemory(lpdword_t base_addr_ptr,
     XELOGW("Game setting EXECUTE bit on allocation");
   }
 
-  // Adjust size.
-  uint32_t page_size = 4096;
-  if (alloc_type & X_MEM_LARGE_PAGES) {
-    page_size = 64 * 1024;
+  uint32_t page_size;
+  if (*base_addr_ptr != 0) {
+    // ignore specified page size when base address is specified.
+    auto heap = kernel_memory()->LookupHeap(*base_addr_ptr);
+    page_size = heap->page_size();
+  } else {
+    // Adjust size.
+    page_size = 4 * 1024;
+    if (alloc_type & X_MEM_LARGE_PAGES) {
+      page_size = 64 * 1024;
+    }
   }
 
   // Round the base address down to the nearest page boundary.