kernel: Add 12 GiB heap support

- Increased heap region from 8 GiB to 12 GiB
- Fixed memory manager page reference count allocation
- Made resource region sizing dynamic for >8GB DRAM
- Increased physical address space bits to support 16GB

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/core/device_memory_manager.h

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -120,8 +121,8 @@ public:
 private:
     static constexpr size_t device_virtual_bits = Traits::device_virtual_bits;
     static constexpr size_t device_as_size = 1ULL << device_virtual_bits;
-    static constexpr size_t physical_min_bits = 32;
+    static constexpr size_t physical_min_bits = 32;  // 4GB
-    static constexpr size_t physical_max_bits = 33;
+    static constexpr size_t physical_max_bits = 34;  // 16GB (increased to support 12GB+ DRAM)
     static constexpr size_t page_bits = 12;
     static constexpr size_t page_size = 1ULL << page_bits;
     static constexpr size_t page_mask = page_size - 1ULL;

src/core/hle/kernel/k_address_space_info.cpp

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <array>
@@ -16,6 +17,8 @@ using namespace Common::Literals;
 constexpr u64 Size_Invalid = UINT64_MAX;
 
 // clang-format off
+// Address space layout information for different process address space configurations.
+// Heap size increased from 8_GiB to 12_GiB to support games that require larger heap allocations
 constexpr std::array<KAddressSpaceInfo, 13> AddressSpaceInfos{{
    { .bit_width = 32, .address = 2_MiB       , .size = 1_GiB   - 2_MiB  , .type = KAddressSpaceInfo::Type::MapSmall, },
    { .bit_width = 32, .address = 1_GiB       , .size = 4_GiB   - 1_GiB  , .type = KAddressSpaceInfo::Type::MapLarge, },
@@ -23,7 +26,7 @@ constexpr std::array<KAddressSpaceInfo, 13> AddressSpaceInfos{{
    { .bit_width = 32, .address = Size_Invalid, .size = 1_GiB            , .type = KAddressSpaceInfo::Type::Heap,     },
    { .bit_width = 36, .address = 128_MiB     , .size = 2_GiB   - 128_MiB, .type = KAddressSpaceInfo::Type::MapSmall, },
    { .bit_width = 36, .address = 2_GiB       , .size = 64_GiB  - 2_GiB  , .type = KAddressSpaceInfo::Type::MapLarge, },
-   { .bit_width = 36, .address = Size_Invalid, .size = 8_GiB            , .type = KAddressSpaceInfo::Type::Heap,     },
+   { .bit_width = 36, .address = Size_Invalid, .size = 12_GiB           , .type = KAddressSpaceInfo::Type::Heap,     },
    { .bit_width = 36, .address = Size_Invalid, .size = 6_GiB            , .type = KAddressSpaceInfo::Type::Alias,    },
 #ifdef HAS_NCE
    // With NCE, we use a 38-bit address space due to memory limitations. This should (safely) truncate ASLR region.
@@ -32,7 +35,7 @@ constexpr std::array<KAddressSpaceInfo, 13> AddressSpaceInfos{{
    { .bit_width = 39, .address = 128_MiB     , .size = 512_GiB - 128_MiB, .type = KAddressSpaceInfo::Type::Map39Bit, },
 #endif
    { .bit_width = 39, .address = Size_Invalid, .size = 64_GiB           , .type = KAddressSpaceInfo::Type::MapSmall  },
-   { .bit_width = 39, .address = Size_Invalid, .size = 8_GiB            , .type = KAddressSpaceInfo::Type::Heap,     },
+   { .bit_width = 39, .address = Size_Invalid, .size = 12_GiB           , .type = KAddressSpaceInfo::Type::Heap,     },
    { .bit_width = 39, .address = Size_Invalid, .size = 64_GiB           , .type = KAddressSpaceInfo::Type::Alias,    },
    { .bit_width = 39, .address = Size_Invalid, .size = 2_GiB            , .type = KAddressSpaceInfo::Type::Stack,    },
 }};

src/core/hle/kernel/k_memory_layout.cpp

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <array>
@@ -158,7 +159,17 @@ void KMemoryLayout::InitializeLinearMemoryRegionTrees(KPhysicalAddress aligned_l
 }
 
 size_t KMemoryLayout::GetResourceRegionSizeForInit(bool use_extra_resource) {
-    return KernelResourceSize + KSystemControl::SecureAppletMemorySize +
+    // Calculate kernel page table heap size based on actual memory size to support > 8GB DRAM
+    const size_t actual_memory_size = KSystemControl::Init::GetIntendedMemorySize();
+    const size_t actual_pt_heap_size = GetMaximumOverheadSize(actual_memory_size);
+
+    // Use the larger of static or dynamic calculation to ensure sufficient space
+    const size_t kernel_pt_heap = std::max(KernelPageTableHeapSize, actual_pt_heap_size);
+
+    const size_t base_resource_size = kernel_pt_heap + KernelInitialPageHeapSize +
+                                     KernelSlabHeapSize + KernelPageBufferHeapSize;
+
+    return base_resource_size + KSystemControl::SecureAppletMemorySize +
            (use_extra_resource ? KernelSlabHeapAdditionalSize + KernelPageBufferAdditionalSize : 0);
 }
 

src/core/hle/kernel/k_memory_layout.h

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -27,6 +28,9 @@ constexpr std::size_t GetMaximumOverheadSize(std::size_t size) {
 constexpr std::size_t MainMemorySize = 4_GiB;
 constexpr std::size_t MainMemorySizeMax = 8_GiB;
 
+// Maximum heap size that can be allocated by applications (increased to support large games)
+constexpr std::size_t MaxHeapSize = 12_GiB;
+
 constexpr std::size_t ReservedEarlyDramSize = 384_KiB;
 constexpr std::size_t DramPhysicalAddress = 0x80000000;
 
@@ -53,6 +57,8 @@ constexpr std::size_t KernelPhysicalAddressSpaceSize =
     KernelPhysicalAddressSpaceEnd - KernelPhysicalAddressSpaceBase;
 constexpr std::size_t KernelPhysicalAddressCodeBase = DramPhysicalAddress + ReservedEarlyDramSize;
 
+// Use MainMemorySizeMax for conservative page table heap allocation
+// This keeps kernel overhead reasonable while supporting up to 16GB DRAM
 constexpr std::size_t KernelPageTableHeapSize = GetMaximumOverheadSize(MainMemorySizeMax);
 constexpr std::size_t KernelInitialPageHeapSize = 128_KiB;
 

src/core/hle/kernel/k_memory_manager.cpp

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <algorithm>
@@ -446,8 +447,8 @@ size_t KMemoryManager::Impl::Initialize(KPhysicalAddress address, size_t size,
     // Setup region.
     m_pool = p;
     m_management_region = management;
-    m_page_reference_counts.resize(
+    // Allocate page reference counts based on actual managed size, not total memory size
-        Kernel::Board::Nintendo::Nx::KSystemControl::Init::GetIntendedMemorySize() / PageSize);
+    m_page_reference_counts.resize(size / PageSize);
     ASSERT(Common::IsAligned(GetInteger(m_management_region), PageSize));
 
     // Initialize the manager's KPageHeap.

src/core/hle/kernel/svc/svc_physical_memory.cpp

@@ -1,7 +1,9 @@
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "core/core.h"
+#include "core/hle/kernel/k_memory_layout.h"
 #include "core/hle/kernel/k_process.h"
 #include "core/hle/kernel/svc.h"
 
@@ -12,8 +14,9 @@ Result SetHeapSize(Core::System& system, u64* out_address, u64 size) {
     LOG_TRACE(Kernel_SVC, "called, heap_size=0x{:X}", size);
 
     // Validate size.
-    R_UNLESS(Common::IsAligned(size, HeapSizeAlignment), ResultInvalidSize);
+    // Check alignment and size limits for 12GiB heap support.
-    R_UNLESS(size < MainMemorySizeMax, ResultInvalidSize);
+    R_UNLESS((size & 0xfffffffc001fffff) == 0, ResultInvalidSize);
+    R_UNLESS(size < MaxHeapSize, ResultInvalidSize);
 
     // Set the heap size.
     KProcessAddress address{};