Kernel: Add more infrastructure to support different memory layouts

This adds some structures necessary to support multiple memory regions
in the future. It also adds support for different system memory types
and the new linear heap mapping at 0x30000000.

src/core/hle/kernel/memory.cpp

@@ -11,6 +11,7 @@
 #include "common/logging/log.h"
 
 #include "core/hle/config_mem.h"
+#include "core/hle/kernel/memory.h"
 #include "core/hle/kernel/vm_manager.h"
 #include "core/hle/result.h"
 #include "core/hle/shared_page.h"
@@ -19,6 +20,77 @@
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+namespace Kernel {
+
+static MemoryRegionInfo memory_regions[3];
+
+/// Size of the APPLICATION, SYSTEM and BASE memory regions (respectively) for each sytem
+/// memory configuration type.
+static const u32 memory_region_sizes[8][3] = {
+    // Old 3DS layouts
+    {0x04000000, 0x02C00000, 0x01400000}, // 0
+    { /* This appears to be unused. */ }, // 1
+    {0x06000000, 0x00C00000, 0x01400000}, // 2
+    {0x05000000, 0x01C00000, 0x01400000}, // 3
+    {0x04800000, 0x02400000, 0x01400000}, // 4
+    {0x02000000, 0x04C00000, 0x01400000}, // 5
+
+    // New 3DS layouts
+    {0x07C00000, 0x06400000, 0x02000000}, // 6
+    {0x0B200000, 0x02E00000, 0x02000000}, // 7
+};
+
+void MemoryInit(u32 mem_type) {
+    // TODO(yuriks): On the n3DS, all o3DS configurations (<=5) are forced to 6 instead.
+    ASSERT_MSG(mem_type <= 5, "New 3DS memory configuration aren't supported yet!");
+    ASSERT(mem_type != 1);
+
+    // The kernel allocation regions (APPLICATION, SYSTEM and BASE) are laid out in sequence, with
+    // the sizes specified in the memory_region_sizes table.
+    VAddr base = 0;
+    for (int i = 0; i < 3; ++i) {
+        memory_regions[i].base = base;
+        memory_regions[i].size = memory_region_sizes[mem_type][i];
+        memory_regions[i].linear_heap_memory = std::make_shared<std::vector<u8>>();
+
+        base += memory_regions[i].size;
+    }
+
+    // We must've allocated the entire FCRAM by the end
+    ASSERT(base == Memory::FCRAM_SIZE);
+
+    using ConfigMem::config_mem;
+    config_mem.app_mem_type = mem_type;
+    // app_mem_malloc does not always match the configured size for memory_region[0]: in case the
+    // n3DS type override is in effect it reports the size the game expects, not the real one.
+    config_mem.app_mem_alloc = memory_region_sizes[mem_type][0];
+    config_mem.sys_mem_alloc = memory_regions[1].size;
+    config_mem.base_mem_alloc = memory_regions[2].size;
+}
+
+void MemoryShutdown() {
+    for (auto& region : memory_regions) {
+        region.base = 0;
+        region.size = 0;
+        region.linear_heap_memory = nullptr;
+    }
+}
+
+MemoryRegionInfo* GetMemoryRegion(MemoryRegion region) {
+    switch (region) {
+    case MemoryRegion::APPLICATION:
+        return &memory_regions[0];
+    case MemoryRegion::SYSTEM:
+        return &memory_regions[1];
+    case MemoryRegion::BASE:
+        return &memory_regions[2];
+    default:
+        UNREACHABLE();
+    }
+}
+
+}
+
 namespace Memory {
 
 namespace {