diff --git a/libctru/include/3ds/os.h b/libctru/include/3ds/os.h
index 690ce7a..e94feb1 100644
--- a/libctru/include/3ds/os.h
+++ b/libctru/include/3ds/os.h
@@ -26,6 +26,36 @@
 /// Retrieves the revision version from a packed system version.
 #define GET_VERSION_REVISION(version) (((version)>> 8)&0xFF)
 
+#define OS_HEAP_AREA_BEGIN 0x08000000 ///< Start of the heap area in the virtual address space
+#define OS_HEAP_AREA_END   0x0E000000 ///< End of the heap area in the virtual address space
+
+#define OS_MAP_AREA_BEGIN  0x10000000 ///< Start of the mappable area in the virtual address space
+#define OS_MAP_AREA_END    0x14000000 ///< End of the mappable area in the virtual address space
+
+#define OS_OLD_FCRAM_VADDR 0x14000000 ///< Old pre-8.x linear FCRAM mapping virtual address
+#define OS_OLD_FCRAM_PADDR 0x20000000 ///< Old pre-8.x linear FCRAM mapping physical address
+#define OS_OLD_FCRAM_SIZE  0x8000000  ///< Old pre-8.x linear FCRAM mapping size (128 MiB)
+
+#define OS_QTMRAM_VADDR    0x1E800000 ///< New3DS QTM memory virtual address
+#define OS_QTMRAM_PADDR    0x1F000000 ///< New3DS QTM memory physical address
+#define OS_QTMRAM_SIZE     0x400000   ///< New3DS QTM memory size (4 MiB; last 128 KiB reserved by kernel)
+
+#define OS_MMIO_VADDR      0x1EC00000 ///< Memory mapped IO range virtual address
+#define OS_MMIO_PADDR      0x10100000 ///< Memory mapped IO range physical address
+#define OS_MMIO_SIZE       0x400000   ///< Memory mapped IO range size (4 MiB)
+
+#define OS_VRAM_VADDR      0x1F000000 ///< VRAM virtual address
+#define OS_VRAM_PADDR      0x18000000 ///< VRAM physical address
+#define OS_VRAM_SIZE       0x600000   ///< VRAM size (6 MiB)
+
+#define OS_DSPRAM_VADDR    0x1FF00000 ///< DSP memory virtual address
+#define OS_DSPRAM_PADDR    0x1FF00000 ///< DSP memory physical address
+#define OS_DSPRAM_SIZE     0x80000    ///< DSP memory size (512 KiB)
+
+#define OS_FCRAM_VADDR     0x30000000 ///< Linear FCRAM mapping virtual address
+#define OS_FCRAM_PADDR     0x20000000 ///< Linear FCRAM mapping physical address
+#define OS_FCRAM_SIZE      0x10000000 ///< Linear FCRAM mapping size (256 MiB)
+
 /// Tick counter.
 typedef struct
 {
diff --git a/libctru/source/allocator/vram.cpp b/libctru/source/allocator/vram.cpp
index 30498a5..14838fa 100644
--- a/libctru/source/allocator/vram.cpp
+++ b/libctru/source/allocator/vram.cpp
@@ -1,6 +1,7 @@
 extern "C"
 {
 	#include <3ds/types.h>
+	#include <3ds/os.h>
 	#include <3ds/allocator/vram.h>
 	#include <3ds/util/rbtree.h>
 }
@@ -12,7 +13,7 @@ static MemPool sVramPool;
 
 static bool vramInit()
 {
-	auto blk = MemBlock::Create((u8*)0x1F000000, 0x00600000);
+	auto blk = MemBlock::Create((u8*)OS_VRAM_VADDR, OS_VRAM_SIZE);
 	if (blk)
 	{
 		sVramPool.AddBlock(blk);
diff --git a/libctru/source/os.c b/libctru/source/os.c
index 0eabfd4..3b95a17 100644
--- a/libctru/source/os.c
+++ b/libctru/source/os.c
@@ -29,14 +29,18 @@ __attribute__((weak)) bool __ctru_speedup = false;
 u32 osConvertVirtToPhys(const void* addr) {
 //---------------------------------------------------------------------------------
 	u32 vaddr = (u32)addr;
-	if(vaddr >= 0x14000000 && vaddr < 0x1c000000)
-		return vaddr + 0x0c000000; // LINEAR heap
-	if(vaddr >= 0x1F000000 && vaddr < 0x1F600000)
-		return vaddr - 0x07000000; // VRAM
-	if(vaddr >= 0x1FF00000 && vaddr < 0x1FF80000)
-		return vaddr + 0x00000000; // DSP memory
-	if(vaddr >= 0x30000000 && vaddr < 0x40000000)
-		return vaddr - 0x10000000; // Only available under FIRM v8+ for certain processes.
+#define CONVERT_REGION(_name) \
+	if (vaddr >= OS_##_name##_VADDR && vaddr < (OS_##_name##_VADDR + OS_##_name##_SIZE)) \
+		return vaddr + (OS_##_name##_PADDR - OS_##_name##_VADDR);
+
+	CONVERT_REGION(FCRAM);
+	CONVERT_REGION(VRAM);
+	CONVERT_REGION(OLD_FCRAM);
+	CONVERT_REGION(DSPRAM);
+	CONVERT_REGION(QTMRAM);
+	CONVERT_REGION(MMIO);
+
+#undef CONVERT_REGION
 	return 0;
 }
 
@@ -44,9 +48,11 @@ u32 osConvertVirtToPhys(const void* addr) {
 void* osConvertOldLINEARMemToNew(const void* addr) {
 //---------------------------------------------------------------------------------
 	u32 vaddr = (u32)addr;
-	if(vaddr >= 0x30000000 && vaddr < 0x40000000)return (void*)vaddr;
-	if(vaddr >= 0x14000000 && vaddr < 0x1c000000)return (void*)(vaddr+0x1c000000);
-	return 0;
+	if (vaddr >= OS_FCRAM_VADDR && vaddr < (OS_FCRAM_VADDR+OS_FCRAM_SIZE))
+		return (void*)vaddr;
+	if (vaddr >= OS_OLD_FCRAM_VADDR && vaddr < (OS_FCRAM_VADDR+OS_OLD_FCRAM_SIZE))
+		return (void*)(vaddr + (OS_FCRAM_VADDR-OS_OLD_FCRAM_VADDR));
+	return NULL;
 }
 
 //---------------------------------------------------------------------------------
diff --git a/libctru/source/system/allocateHeaps.c b/libctru/source/system/allocateHeaps.c
index d35b4d6..0c8478d 100644
--- a/libctru/source/system/allocateHeaps.c
+++ b/libctru/source/system/allocateHeaps.c
@@ -33,14 +33,14 @@ void __attribute__((weak)) __system_allocateHeaps(void) {
 	}
 
 	// Allocate the application heap
-	__ctru_heap = 0x08000000;
+	__ctru_heap = OS_HEAP_AREA_BEGIN;
 	svcControlMemory(&tmp, __ctru_heap, 0x0, __ctru_heap_size, MEMOP_ALLOC, MEMPERM_READ | MEMPERM_WRITE);
 
 	// Allocate the linear heap
 	svcControlMemory(&__ctru_linear_heap, 0x0, 0x0, __ctru_linear_heap_size, MEMOP_ALLOC_LINEAR, MEMPERM_READ | MEMPERM_WRITE);
 
 	// Mappable allocator init
-	mappableInit(0x10000000, 0x14000000);
+	mappableInit(OS_MAP_AREA_BEGIN, OS_MAP_AREA_END);
 
 	// Set up newlib heap
 	fake_heap_start = (char*)__ctru_heap;