kern: move SecureAppletMemory/KPageBuffer heap into the ResourceRegion

libraries/libmesosphere/include/mesosphere/board/nintendo/nx/kern_k_system_control.hpp

@@ -20,6 +20,9 @@
 namespace ams::kern::board::nintendo::nx {
 
     class KSystemControl : public KSystemControlBase {
+        public:
+            /* This can be overridden as needed. */
+            static constexpr size_t SecureAppletMemorySize = 4_MB;
         public:
             class Init : public KSystemControlBase::Init {
                 public:

libraries/libmesosphere/include/mesosphere/init/kern_init_slab_setup.hpp

@@ -42,7 +42,6 @@ namespace ams::kern::init {
     const KSlabResourceCounts &GetSlabResourceCounts();
 
     size_t CalculateTotalSlabHeapSize();
-    NOINLINE void InitializeKPageBufferSlabHeap();
     NOINLINE void InitializeSlabHeaps();
 
 }

libraries/libmesosphere/include/mesosphere/kern_k_dynamic_page_manager.hpp

@@ -38,30 +38,37 @@ namespace ams::kern {
             size_t m_peak;
             size_t m_count;
             KVirtualAddress m_address;
+            KVirtualAddress m_aligned_address;
             size_t m_size;
         public:
-            KDynamicPageManager() : m_lock(), m_page_bitmap(), m_used(), m_peak(), m_count(), m_address(Null<KVirtualAddress>), m_size() { /* ... */ }
+            KDynamicPageManager() : m_lock(), m_page_bitmap(), m_used(), m_peak(), m_count(), m_address(Null<KVirtualAddress>), m_aligned_address(Null<KVirtualAddress>), m_size() { /* ... */ }
 
-            Result Initialize(KVirtualAddress memory, size_t sz) {
+            Result Initialize(KVirtualAddress memory, size_t size, size_t align) {
                 /* We need to have positive size. */
-                R_UNLESS(sz > 0, svc::ResultOutOfMemory());
+                R_UNLESS(size > 0, svc::ResultOutOfMemory());
 
-                /* Calculate management overhead. */
+                /* Set addresses. */
-                const size_t management_size  = KPageBitmap::CalculateManagementOverheadSize(sz / sizeof(PageBuffer));
+                m_address         = memory;
-                const size_t allocatable_size = sz - management_size;
+                m_aligned_address = util::AlignDown(GetInteger(memory), align);
+
+                /* Calculate extents. */
+                const size_t managed_size  = m_address + size - m_aligned_address;
+                const size_t overhead_size = util::AlignUp(KPageBitmap::CalculateManagementOverheadSize(managed_size / sizeof(PageBuffer)), sizeof(PageBuffer));
+                R_UNLESS(overhead_size < size, svc::ResultOutOfMemory());
 
                 /* Set tracking fields. */
-                m_address = memory;
+                m_size  = util::AlignDown(size - overhead_size, sizeof(PageBuffer));
-                m_size    = util::AlignDown(allocatable_size, sizeof(PageBuffer));
+                m_count = m_size / sizeof(PageBuffer);
-                m_count   = allocatable_size / sizeof(PageBuffer);
-                R_UNLESS(m_count > 0, svc::ResultOutOfMemory());
 
                 /* Clear the management region. */
-                u64 *management_ptr = GetPointer<u64>(m_address + allocatable_size);
+                u64 *management_ptr = GetPointer<u64>(m_address + size - overhead_size);
-                std::memset(management_ptr, 0, management_size);
+                std::memset(management_ptr, 0, overhead_size);
 
                 /* Initialize the bitmap. */
-                m_page_bitmap.Initialize(management_ptr, m_count);
+                const size_t allocatable_region_size = (GetInteger(m_address) + size - overhead_size) - GetInteger(m_aligned_address);
+                MESOSPHERE_ABORT_UNLESS(allocatable_region_size >= sizeof(PageBuffer));
+
+                m_page_bitmap.Initialize(management_ptr, allocatable_region_size / sizeof(PageBuffer));
 
                 /* Free the pages to the bitmap. */
                 for (size_t i = 0; i < m_count; i++) {
@@ -69,7 +76,7 @@ namespace ams::kern {
                     cpu::ClearPageToZero(GetPointer<PageBuffer>(m_address) + i);
 
                     /* Set the bit for the free page. */
-                    m_page_bitmap.SetBit(i);
+                    m_page_bitmap.SetBit((GetInteger(m_address) + (i * sizeof(PageBuffer)) - GetInteger(m_aligned_address)) / sizeof(PageBuffer));
                 }
 
                 R_SUCCEED();
@@ -98,7 +105,28 @@ namespace ams::kern {
                 m_page_bitmap.ClearBit(offset);
                 m_peak = std::max(m_peak, (++m_used));
 
-                return GetPointer<PageBuffer>(m_address) + offset;
+                return GetPointer<PageBuffer>(m_aligned_address) + offset;
+            }
+
+            PageBuffer *Allocate(size_t count) {
+                /* Take the lock. */
+                KScopedInterruptDisable di;
+                KScopedSpinLock lk(m_lock);
+
+                /* Find a random free block. */
+                ssize_t soffset = m_page_bitmap.FindFreeRange(count);
+                if (AMS_UNLIKELY(soffset < 0)) {
+                    return nullptr;
+                }
+
+                const size_t offset = static_cast<size_t>(soffset);
+
+                /* Update our tracking. */
+                m_page_bitmap.ClearRange(offset, count);
+                m_used += count;
+                m_peak = std::max(m_peak, m_used);
+
+                return GetPointer<PageBuffer>(m_aligned_address) + offset;
             }
 
             void Free(PageBuffer *pb) {
@@ -110,7 +138,7 @@ namespace ams::kern {
                 KScopedSpinLock lk(m_lock);
 
                 /* Set the bit for the free page. */
-                size_t offset = (reinterpret_cast<uintptr_t>(pb) - GetInteger(m_address)) / sizeof(PageBuffer);
+                size_t offset = (reinterpret_cast<uintptr_t>(pb) - GetInteger(m_aligned_address)) / sizeof(PageBuffer);
                 m_page_bitmap.SetBit(offset);
 
                 /* Decrement our used count. */

libraries/libmesosphere/include/mesosphere/kern_k_memory_block.hpp

@@ -43,6 +43,7 @@ namespace ams::kern {
         KMemoryState_FlagCanMapProcess          = (1 << 23),
         KMemoryState_FlagCanChangeAttribute     = (1 << 24),
         KMemoryState_FlagCanCodeMemory          = (1 << 25),
+        KMemoryState_FlagLinearMapped           = (1 << 26),
 
         KMemoryState_FlagsData = KMemoryState_FlagCanReprotect          | KMemoryState_FlagCanUseIpc            |
                                  KMemoryState_FlagCanUseNonDeviceIpc    | KMemoryState_FlagCanUseNonSecureIpc   |
@@ -50,16 +51,18 @@ namespace ams::kern {
                                  KMemoryState_FlagCanTransfer           | KMemoryState_FlagCanQueryPhysical     |
                                  KMemoryState_FlagCanDeviceMap          | KMemoryState_FlagCanAlignedDeviceMap  |
                                  KMemoryState_FlagCanIpcUserBuffer      | KMemoryState_FlagReferenceCounted     |
-                                 KMemoryState_FlagCanChangeAttribute,
+                                 KMemoryState_FlagCanChangeAttribute    | KMemoryState_FlagLinearMapped,
 
         KMemoryState_FlagsCode = KMemoryState_FlagCanDebug              | KMemoryState_FlagCanUseIpc            |
                                  KMemoryState_FlagCanUseNonDeviceIpc    | KMemoryState_FlagCanUseNonSecureIpc   |
                                  KMemoryState_FlagMapped                | KMemoryState_FlagCode                 |
                                  KMemoryState_FlagCanQueryPhysical      | KMemoryState_FlagCanDeviceMap         |
-                                 KMemoryState_FlagCanAlignedDeviceMap   | KMemoryState_FlagReferenceCounted,
+                                 KMemoryState_FlagCanAlignedDeviceMap   | KMemoryState_FlagReferenceCounted     |
+                                 KMemoryState_FlagLinearMapped,
 
         KMemoryState_FlagsMisc = KMemoryState_FlagMapped                | KMemoryState_FlagReferenceCounted     |
-                                 KMemoryState_FlagCanQueryPhysical      | KMemoryState_FlagCanDeviceMap,
+                                 KMemoryState_FlagCanQueryPhysical      | KMemoryState_FlagCanDeviceMap         |
+                                 KMemoryState_FlagLinearMapped,
 
 
         KMemoryState_Free               = ams::svc::MemoryState_Free,
@@ -68,7 +71,7 @@ namespace ams::kern {
         KMemoryState_Code               = ams::svc::MemoryState_Code                | KMemoryState_FlagsCode  | KMemoryState_FlagCanMapProcess,
         KMemoryState_CodeData           = ams::svc::MemoryState_CodeData            | KMemoryState_FlagsData  | KMemoryState_FlagCanMapProcess       | KMemoryState_FlagCanCodeMemory,
         KMemoryState_Normal             = ams::svc::MemoryState_Normal              | KMemoryState_FlagsData  | KMemoryState_FlagCanCodeMemory,
-        KMemoryState_Shared             = ams::svc::MemoryState_Shared              | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted,
+        KMemoryState_Shared             = ams::svc::MemoryState_Shared              | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted    | KMemoryState_FlagLinearMapped,
 
         /* KMemoryState_Alias was removed after 1.0.0. */
 
@@ -82,7 +85,7 @@ namespace ams::kern {
         KMemoryState_Stack              = ams::svc::MemoryState_Stack               | KMemoryState_FlagsMisc  | KMemoryState_FlagCanAlignedDeviceMap
                                                                                                               | KMemoryState_FlagCanUseIpc           | KMemoryState_FlagCanUseNonSecureIpc | KMemoryState_FlagCanUseNonDeviceIpc,
 
-        KMemoryState_ThreadLocal        = ams::svc::MemoryState_ThreadLocal         | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted,
+        KMemoryState_ThreadLocal        = ams::svc::MemoryState_ThreadLocal         | KMemoryState_FlagMapped | KMemoryState_FlagLinearMapped,
 
         KMemoryState_Transfered         = ams::svc::MemoryState_Transfered          | KMemoryState_FlagsMisc  | KMemoryState_FlagCanAlignedDeviceMap | KMemoryState_FlagCanChangeAttribute
                                                                                                               | KMemoryState_FlagCanUseIpc           | KMemoryState_FlagCanUseNonSecureIpc | KMemoryState_FlagCanUseNonDeviceIpc,
@@ -90,7 +93,7 @@ namespace ams::kern {
         KMemoryState_SharedTransfered   = ams::svc::MemoryState_SharedTransfered    | KMemoryState_FlagsMisc  | KMemoryState_FlagCanAlignedDeviceMap
                                                                                                               | KMemoryState_FlagCanUseNonSecureIpc  | KMemoryState_FlagCanUseNonDeviceIpc,
 
-        KMemoryState_SharedCode         = ams::svc::MemoryState_SharedCode          | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted
+        KMemoryState_SharedCode         = ams::svc::MemoryState_SharedCode          | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted    | KMemoryState_FlagLinearMapped
                                                                                                               | KMemoryState_FlagCanUseNonSecureIpc  | KMemoryState_FlagCanUseNonDeviceIpc,
 
         KMemoryState_Inaccessible       = ams::svc::MemoryState_Inaccessible,
@@ -103,8 +106,8 @@ namespace ams::kern {
 
         KMemoryState_Kernel             = ams::svc::MemoryState_Kernel              | KMemoryState_FlagMapped,
 
-        KMemoryState_GeneratedCode      = ams::svc::MemoryState_GeneratedCode       | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted    | KMemoryState_FlagCanDebug,
+        KMemoryState_GeneratedCode      = ams::svc::MemoryState_GeneratedCode       | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted    | KMemoryState_FlagCanDebug           | KMemoryState_FlagLinearMapped,
-        KMemoryState_CodeOut            = ams::svc::MemoryState_CodeOut             | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted,
+        KMemoryState_CodeOut            = ams::svc::MemoryState_CodeOut             | KMemoryState_FlagMapped | KMemoryState_FlagReferenceCounted    | KMemoryState_FlagLinearMapped,
 
         KMemoryState_Coverage           = ams::svc::MemoryState_Coverage            | KMemoryState_FlagMapped,
     };
@@ -113,25 +116,25 @@ namespace ams::kern {
     static_assert(KMemoryState_Free             == 0x00000000);
     static_assert(KMemoryState_Io               == 0x00182001);
     static_assert(KMemoryState_Static           == 0x00042002);
-    static_assert(KMemoryState_Code             == 0x00DC7E03);
+    static_assert(KMemoryState_Code             == 0x04DC7E03);
-    static_assert(KMemoryState_CodeData         == 0x03FEBD04);
+    static_assert(KMemoryState_CodeData         == 0x07FEBD04);
-    static_assert(KMemoryState_Normal           == 0x037EBD05);
+    static_assert(KMemoryState_Normal           == 0x077EBD05);
-    static_assert(KMemoryState_Shared           == 0x00402006);
+    static_assert(KMemoryState_Shared           == 0x04402006);
 
-    static_assert(KMemoryState_AliasCode        == 0x00DD7E08);
+    static_assert(KMemoryState_AliasCode        == 0x04DD7E08);
-    static_assert(KMemoryState_AliasCodeData    == 0x03FFBD09);
+    static_assert(KMemoryState_AliasCodeData    == 0x07FFBD09);
-    static_assert(KMemoryState_Ipc              == 0x005C3C0A);
+    static_assert(KMemoryState_Ipc              == 0x045C3C0A);
-    static_assert(KMemoryState_Stack            == 0x005C3C0B);
+    static_assert(KMemoryState_Stack            == 0x045C3C0B);
-    static_assert(KMemoryState_ThreadLocal      == 0x0040200C);
+    static_assert(KMemoryState_ThreadLocal      == 0x0400200C);
-    static_assert(KMemoryState_Transfered       == 0x015C3C0D);
+    static_assert(KMemoryState_Transfered       == 0x055C3C0D);
-    static_assert(KMemoryState_SharedTransfered == 0x005C380E);
+    static_assert(KMemoryState_SharedTransfered == 0x045C380E);
-    static_assert(KMemoryState_SharedCode       == 0x0040380F);
+    static_assert(KMemoryState_SharedCode       == 0x0440380F);
     static_assert(KMemoryState_Inaccessible     == 0x00000010);
-    static_assert(KMemoryState_NonSecureIpc     == 0x005C3811);
+    static_assert(KMemoryState_NonSecureIpc     == 0x045C3811);
-    static_assert(KMemoryState_NonDeviceIpc     == 0x004C2812);
+    static_assert(KMemoryState_NonDeviceIpc     == 0x044C2812);
     static_assert(KMemoryState_Kernel           == 0x00002013);
-    static_assert(KMemoryState_GeneratedCode    == 0x00402214);
+    static_assert(KMemoryState_GeneratedCode    == 0x04402214);
-    static_assert(KMemoryState_CodeOut          == 0x00402015);
+    static_assert(KMemoryState_CodeOut          == 0x04402015);
     static_assert(KMemoryState_Coverage         == 0x00002016);
 #endif
 

libraries/libmesosphere/include/mesosphere/kern_k_memory_layout.hpp

@@ -50,9 +50,11 @@ namespace ams::kern {
     constexpr size_t KernelSlabHeapSize               = KernelSlabHeapDataSize + KernelSlabHeapGapsSizeMax;
 
     /* NOTE: This is calculated from KThread slab counts, assuming KThread size <= 0x800. */
+    constexpr size_t KernelPageBufferHeapSize         = 0x3E0000;
     constexpr size_t KernelSlabHeapAdditionalSize     = 0x148000;
+    constexpr size_t KernelPageBufferAdditionalSize   = 0x33C000;
 
-    constexpr size_t KernelResourceSize               = KernelPageTableHeapSize + KernelInitialPageHeapSize + KernelSlabHeapSize;
+    constexpr size_t KernelResourceSize               = KernelPageTableHeapSize + KernelInitialPageHeapSize + KernelSlabHeapSize + KernelPageBufferHeapSize;
 
     class KMemoryLayout {
         private:
@@ -150,6 +152,8 @@ namespace ams::kern {
 
             static MESOSPHERE_NOINLINE_IF_DEBUG const KMemoryRegion &GetKernelTraceBufferRegion() { return Dereference(GetVirtualLinearMemoryRegionTree().FindByType(KMemoryRegionType_VirtualDramKernelTraceBuffer)); }
 
+            static MESOSPHERE_NOINLINE_IF_DEBUG const KMemoryRegion &GetSecureAppletMemoryRegion() { return Dereference(GetVirtualMemoryRegionTree().FindByType(KMemoryRegionType_VirtualDramKernelSecureAppletMemory)); }
+
             static MESOSPHERE_NOINLINE_IF_DEBUG const KMemoryRegion &GetVirtualLinearRegion(KVirtualAddress address) { return Dereference(FindLinear(address)); }
             static MESOSPHERE_NOINLINE_IF_DEBUG const KMemoryRegion &GetPhysicalLinearRegion(KPhysicalAddress address) { return Dereference(FindLinear(address)); }
 
@@ -209,6 +213,7 @@ namespace ams::kern {
             static MESOSPHERE_NOINLINE_IF_DEBUG auto GetKernelRegionPhysicalExtents() { return GetPhysicalMemoryRegionTree().GetDerivedRegionExtents(KMemoryRegionType_DramKernelBase); }
             static MESOSPHERE_NOINLINE_IF_DEBUG auto GetKernelCodeRegionPhysicalExtents() { return GetPhysicalMemoryRegionTree().GetDerivedRegionExtents(KMemoryRegionType_DramKernelCode); }
             static MESOSPHERE_NOINLINE_IF_DEBUG auto GetKernelSlabRegionPhysicalExtents() { return GetPhysicalMemoryRegionTree().GetDerivedRegionExtents(KMemoryRegionType_DramKernelSlab); }
+            static MESOSPHERE_NOINLINE_IF_DEBUG auto GetKernelSecureAppletMemoryRegionPhysicalExtents() { return GetPhysicalMemoryRegionTree().GetDerivedRegionExtents(KMemoryRegionType_DramKernelSecureAppletMemory); }
             static MESOSPHERE_NOINLINE_IF_DEBUG auto GetKernelPageTableHeapRegionPhysicalExtents() { return GetPhysicalMemoryRegionTree().GetDerivedRegionExtents(KMemoryRegionType_DramKernelPtHeap); }
             static MESOSPHERE_NOINLINE_IF_DEBUG auto GetKernelInitPageTableRegionPhysicalExtents() { return GetPhysicalMemoryRegionTree().GetDerivedRegionExtents(KMemoryRegionType_DramKernelInitPt); }
 

libraries/libmesosphere/include/mesosphere/kern_k_memory_region_type.hpp

@@ -211,6 +211,8 @@ namespace ams::kern {
     static_assert(KMemoryRegionType_DramKernelPtHeap.GetValue() == (0x24E | KMemoryRegionAttr_CarveoutProtected | KMemoryRegionAttr_NoUserMap | KMemoryRegionAttr_LinearMapped));
     static_assert(KMemoryRegionType_DramKernelInitPt.GetValue() == (0x44E | KMemoryRegionAttr_CarveoutProtected | KMemoryRegionAttr_NoUserMap | KMemoryRegionAttr_LinearMapped));
 
+    constexpr inline const auto KMemoryRegionType_DramKernelSecureAppletMemory = KMemoryRegionType_DramKernelBase.DeriveSparse(1, 3, 0).SetAttribute(KMemoryRegionAttr_LinearMapped);
+    static_assert(KMemoryRegionType_DramKernelSecureAppletMemory.GetValue() == (0x18E  | KMemoryRegionAttr_CarveoutProtected | KMemoryRegionAttr_NoUserMap | KMemoryRegionAttr_LinearMapped));
 
     constexpr inline const auto KMemoryRegionType_DramReservedEarly = KMemoryRegionType_DramReservedBase.DeriveAttribute(KMemoryRegionAttr_NoUserMap);
     static_assert(KMemoryRegionType_DramReservedEarly.GetValue() == (0x16 | KMemoryRegionAttr_NoUserMap));
@@ -251,6 +253,9 @@ namespace ams::kern {
     constexpr inline const auto KMemoryRegionType_VirtualDramUnknownDebug = KMemoryRegionType_Dram.DeriveSparse(2, 2, 1);
     static_assert(KMemoryRegionType_VirtualDramUnknownDebug.GetValue() == (0x52));
 
+    constexpr inline const auto KMemoryRegionType_VirtualDramKernelSecureAppletMemory = KMemoryRegionType_Dram.DeriveSparse(3, 1, 0);
+    static_assert(KMemoryRegionType_VirtualDramKernelSecureAppletMemory.GetValue() == (0x62));
+
     constexpr inline const auto KMemoryRegionType_VirtualDramKernelInitPt   = KMemoryRegionType_VirtualDramHeapBase.Derive(3, 0);
     constexpr inline const auto KMemoryRegionType_VirtualDramPoolManagement = KMemoryRegionType_VirtualDramHeapBase.Derive(3, 1);
     constexpr inline const auto KMemoryRegionType_VirtualDramUserPool       = KMemoryRegionType_VirtualDramHeapBase.Derive(3, 2);
@@ -327,6 +332,8 @@ namespace ams::kern {
             return KMemoryRegionType_VirtualDramKernelTraceBuffer;
         } else if (KMemoryRegionType_DramKernelPtHeap.IsAncestorOf(type_id)) {
             return KMemoryRegionType_VirtualDramKernelPtHeap;
+        } else if (KMemoryRegionType_DramKernelSecureAppletMemory.IsAncestorOf(type_id)) {
+            return KMemoryRegionType_VirtualDramKernelSecureAppletMemory;
         } else if ((type_id | KMemoryRegionAttr_ShouldKernelMap) == type_id) {
             return KMemoryRegionType_VirtualDramUnknownDebug;
         } else {

libraries/libmesosphere/include/mesosphere/kern_k_page_bitmap.hpp

@@ -113,11 +113,12 @@ namespace ams::kern {
             static constexpr size_t MaxDepth = 4;
         private:
             u64 *m_bit_storages[MaxDepth];
+            u64 *m_end_storages[MaxDepth];
             RandomBitGenerator m_rng;
             size_t m_num_bits;
             size_t m_used_depths;
         public:
-            KPageBitmap() : m_bit_storages(), m_rng(), m_num_bits(), m_used_depths() { /* ... */ }
+            KPageBitmap() : m_bit_storages(), m_end_storages(), m_rng(), m_num_bits(), m_used_depths() { /* ... */ }
 
             constexpr size_t GetNumBits() const { return m_num_bits; }
             constexpr s32 GetHighestDepthIndex() const { return static_cast<s32>(m_used_depths) - 1; }
@@ -135,6 +136,7 @@ namespace ams::kern {
                     m_bit_storages[depth] = storage;
                     size = util::AlignUp(size, BITSIZEOF(u64)) / BITSIZEOF(u64);
                     storage += size;
+                    m_end_storages[depth] = storage;
                 }
 
                 return storage;
@@ -171,6 +173,45 @@ namespace ams::kern {
                 return static_cast<ssize_t>(offset);
             }
 
+            ssize_t FindFreeRange(size_t count) {
+                /* Check that it is possible to find a range. */
+                const u64 * const storage_start = m_bit_storages[m_used_depths - 1];
+                const u64 * const storage_end   = m_end_storages[m_used_depths - 1];
+
+                /* If we don't have a storage to iterate (or want more blocks than fit in a single storage), we can't find a free range. */
+                if (!(storage_start < storage_end && count <= BITSIZEOF(u64))) {
+                    return -1;
+                }
+
+                /* Walk the storages to select a random free range. */
+                const size_t options_per_storage = std::max<size_t>(BITSIZEOF(u64) / count, 1);
+                const size_t num_entries         = std::max<size_t>(storage_end - storage_start, 1);
+
+                const u64 free_mask = (static_cast<u64>(1) << count) - 1;
+
+                size_t num_valid_options = 0;
+                ssize_t chosen_offset = -1;
+                for (size_t storage_index = 0; storage_index < num_entries; ++storage_index) {
+                    u64 storage = storage_start[storage_index];
+                    for (size_t option = 0; option < options_per_storage; ++option) {
+                        if ((storage & free_mask) == free_mask) {
+                            /* We've found a new valid option. */
+                            ++num_valid_options;
+
+                            /* Select the Kth valid option with probability 1/K. This leads to an overall uniform distribution. */
+                            if (num_valid_options == 1 || m_rng.GenerateRandom(num_valid_options) == 0) {
+                                /* This is our first option, so select it. */
+                                chosen_offset = storage_index * BITSIZEOF(u64) + option * count;
+                            }
+                        }
+                        storage >>= count;
+                    }
+                }
+
+                /* Return the random offset we chose.*/
+                return chosen_offset;
+            }
+
             void SetBit(size_t offset) {
                 this->SetBit(this->GetHighestDepthIndex(), offset);
                 m_num_bits++;

libraries/libmesosphere/include/mesosphere/kern_k_page_buffer.hpp

@@ -16,12 +16,33 @@
 #pragma once
 #include <mesosphere/kern_slab_helpers.hpp>
 #include <mesosphere/kern_k_memory_layout.hpp>
+#include <mesosphere/kern_k_dynamic_page_manager.hpp>
 
 namespace ams::kern {
 
-    class KPageBuffer : public KSlabAllocated<KPageBuffer> {
+    class KDynamicPageManager;
+
+    class KPageBuffer;
+
+    class KPageBufferSlabHeap : protected impl::KSlabHeapImpl {
+        public:
+            static constexpr size_t BufferSize            = PageSize;
+            static constinit inline size_t s_buffer_count = 0;
         private:
-            alignas(PageSize) u8 m_buffer[PageSize];
+            size_t m_obj_size{};
+        public:
+            constexpr KPageBufferSlabHeap() = default;
+
+            /* See kern_init_slab_setup.cpp for definition. */
+            void Initialize(KDynamicPageManager &allocator);
+
+            KPageBuffer *Allocate();
+            void Free(KPageBuffer *pb);
+    };
+
+    class KPageBuffer {
+        private:
+            u8 m_buffer[KPageBufferSlabHeap::BufferSize];
         public:
             KPageBuffer() {
                 std::memset(m_buffer, 0, sizeof(m_buffer));
@@ -39,8 +60,49 @@ namespace ams::kern {
 
                 return GetPointer<KPageBuffer>(virt_addr);
             }
+        private:
+            static constinit inline KPageBufferSlabHeap s_slab_heap;
+        public:
+            static void InitializeSlabHeap(KDynamicPageManager &allocator) {
+                s_slab_heap.Initialize(allocator);
+            }
+
+            static KPageBuffer *Allocate() {
+                return s_slab_heap.Allocate();
+            }
+
+            static void Free(KPageBuffer *obj) {
+                s_slab_heap.Free(obj);
+            }
+
+            template<size_t ExpectedSize>
+            static ALWAYS_INLINE KPageBuffer *AllocateChecked() {
+                /* Check that the allocation is valid. */
+                MESOSPHERE_ABORT_UNLESS(sizeof(KPageBuffer) == ExpectedSize);
+
+                return Allocate();
+            }
+
+            template<size_t ExpectedSize>
+            static ALWAYS_INLINE void FreeChecked(KPageBuffer *obj) {
+                /* Check that the free is valid. */
+                MESOSPHERE_ABORT_UNLESS(sizeof(KPageBuffer) == ExpectedSize);
+
+                return Free(obj);
+            }
     };
-    static_assert(sizeof(KPageBuffer)  == PageSize);
+    static_assert(sizeof(KPageBuffer) == KPageBufferSlabHeap::BufferSize);
-    static_assert(alignof(KPageBuffer) == PageSize);
+
+    ALWAYS_INLINE KPageBuffer *KPageBufferSlabHeap::Allocate() {
+        KPageBuffer *pb = static_cast<KPageBuffer *>(KSlabHeapImpl::Allocate());
+        if (AMS_LIKELY(pb != nullptr)) {
+            std::construct_at(pb);
+        }
+        return pb;
+    }
+
+    ALWAYS_INLINE void KPageBufferSlabHeap::Free(KPageBuffer *pb) {
+        KSlabHeapImpl::Free(pb);
+    }
 
 }

libraries/libmesosphere/include/mesosphere/kern_k_system_control_base.hpp

@@ -26,6 +26,9 @@ namespace ams::kern {
 namespace ams::kern {
 
     class KSystemControlBase {
+        public:
+            /* This can be overridden as needed. */
+            static constexpr size_t SecureAppletMemorySize = 0;
         protected:
             /* Nintendo uses std::mt19937_t for randomness. */
             /* To save space (and because mt19337_t isn't secure anyway), */

libraries/libmesosphere/include/mesosphere/kern_kernel.hpp

@@ -63,7 +63,7 @@ namespace ams::kern {
             static constexpr size_t ApplicationMemoryBlockSlabHeapSize = 20000;
             static constexpr size_t SystemMemoryBlockSlabHeapSize      = 10000;
             static constexpr size_t BlockInfoSlabHeapSize              = 4000;
-            static constexpr size_t ReservedDynamicPageCount           = 70;
+            static constexpr size_t ReservedDynamicPageCount           = 64;
         private:
             static State s_state;
             static KResourceLimit s_system_resource_limit;

libraries/libmesosphere/source/board/nintendo/nx/kern_k_system_control.cpp

@@ -29,7 +29,6 @@ namespace ams::kern::board::nintendo::nx {
         constinit bool g_call_smc_on_panic;
 
         /* Global variables for secure memory. */
-        constexpr size_t SecureAppletMemorySize = 4_MB;
         constinit KSpinLock g_secure_applet_lock;
         constinit bool g_secure_applet_memory_used = false;
         constinit KVirtualAddress g_secure_applet_memory_address = Null<KVirtualAddress>;
@@ -246,8 +245,8 @@ namespace ams::kern::board::nintendo::nx {
 
         Result AllocateSecureMemoryForApplet(KVirtualAddress *out, size_t size) {
             /* Verify that the size is valid. */
-            R_UNLESS(util::IsAligned(size, PageSize), svc::ResultInvalidSize());
+            R_UNLESS(util::IsAligned(size, PageSize),                svc::ResultInvalidSize());
-            R_UNLESS(size <= SecureAppletMemorySize,  svc::ResultOutOfMemory());
+            R_UNLESS(size <= KSystemControl::SecureAppletMemorySize, svc::ResultOutOfMemory());
 
             /* Disable interrupts and acquire the secure applet lock. */
             KScopedInterruptDisable di;
@@ -273,7 +272,7 @@ namespace ams::kern::board::nintendo::nx {
 
             /* Verify that the memory being freed is correct. */
             MESOSPHERE_ABORT_UNLESS(address == g_secure_applet_memory_address);
-            MESOSPHERE_ABORT_UNLESS(size <= SecureAppletMemorySize);
+            MESOSPHERE_ABORT_UNLESS(size <= KSystemControl::SecureAppletMemorySize);
             MESOSPHERE_ABORT_UNLESS(util::IsAligned(size, PageSize));
             MESOSPHERE_ABORT_UNLESS(g_secure_applet_memory_used);
 
@@ -451,17 +450,11 @@ namespace ams::kern::board::nintendo::nx {
         /* Initialize the sleep manager. */
         KSleepManager::Initialize();
 
-        /* Reserve secure applet memory. */
+        /* Get the secure applet memory. */
-        if (GetTargetFirmware() >= TargetFirmware_5_0_0) {
+        const auto &secure_applet_memory = KMemoryLayout::GetSecureAppletMemoryRegion();
-            MESOSPHERE_ABORT_UNLESS(g_secure_applet_memory_address == Null<KVirtualAddress>);
+        MESOSPHERE_INIT_ABORT_UNLESS(secure_applet_memory.GetSize() == SecureAppletMemorySize);
-            MESOSPHERE_ABORT_UNLESS(Kernel::GetSystemResourceLimit().Reserve(ams::svc::LimitableResource_PhysicalMemoryMax, SecureAppletMemorySize));
 
-            constexpr auto SecureAppletAllocateOption = KMemoryManager::EncodeOption(KMemoryManager::Pool_System, KMemoryManager::Direction_FromFront);
+        g_secure_applet_memory_address = secure_applet_memory.GetAddress();
-            const KPhysicalAddress secure_applet_memory_phys_addr = Kernel::GetMemoryManager().AllocateAndOpenContinuous(SecureAppletMemorySize / PageSize, 1, SecureAppletAllocateOption);
-            MESOSPHERE_ABORT_UNLESS(secure_applet_memory_phys_addr != Null<KPhysicalAddress>);
-
-            g_secure_applet_memory_address = KMemoryLayout::GetLinearVirtualAddress(secure_applet_memory_phys_addr);
-        }
 
         /* Initialize KTrace (and potentially other init). */
         KSystemControlBase::InitializePhase2();

libraries/libmesosphere/source/init/kern_init_slab_setup.cpp

@@ -79,6 +79,9 @@ namespace ams::kern::init {
             constexpr size_t RequiredSizeForExtraThreadCount = SlabCountExtraKThread * (sizeof(KThread) + (sizeof(KThreadLocalPage) / 8) + sizeof(KEventInfo));
             static_assert(RequiredSizeForExtraThreadCount <= KernelSlabHeapAdditionalSize);
 
+            static_assert(KernelPageBufferHeapSize == 2 * PageSize + (SlabCountKProcess + SlabCountKThread + (SlabCountKProcess + SlabCountKThread) / 8) * PageSize);
+            static_assert(KernelPageBufferAdditionalSize == (SlabCountExtraKThread + (SlabCountExtraKThread / 8)) * PageSize);
+
         }
 
         /* Global to hold our resource counts. */
@@ -131,7 +134,7 @@ namespace ams::kern::init {
     }
 
     size_t CalculateSlabHeapGapSize() {
-        constexpr size_t KernelSlabHeapGapSize = 2_MB - 296_KB;
+        constexpr size_t KernelSlabHeapGapSize = 2_MB - 320_KB;
         static_assert(KernelSlabHeapGapSize <= KernelSlabHeapGapsSizeMax);
         return KernelSlabHeapGapSize;
     }
@@ -155,23 +158,6 @@ namespace ams::kern::init {
         return size;
     }
 
-    void InitializeKPageBufferSlabHeap() {
-        const auto &counts = GetSlabResourceCounts();
-        const size_t num_pages = counts.num_KProcess + counts.num_KThread + (counts.num_KProcess + counts.num_KThread) / 8;
-        const size_t slab_size = num_pages * PageSize;
-
-        /* Reserve memory from the system resource limit. */
-        MESOSPHERE_ABORT_UNLESS(Kernel::GetSystemResourceLimit().Reserve(ams::svc::LimitableResource_PhysicalMemoryMax, slab_size));
-
-        /* Allocate memory for the slab. */
-        constexpr auto AllocateOption = KMemoryManager::EncodeOption(KMemoryManager::Pool_System, KMemoryManager::Direction_FromFront);
-        const KPhysicalAddress slab_address = Kernel::GetMemoryManager().AllocateAndOpenContinuous(num_pages, 1, AllocateOption);
-        MESOSPHERE_ABORT_UNLESS(slab_address != Null<KPhysicalAddress>);
-
-        /* Initialize the slabheap. */
-        KPageBuffer::InitializeSlabHeap(GetVoidPointer(KMemoryLayout::GetLinearVirtualAddress(slab_address)), slab_size);
-    }
-
     void InitializeSlabHeaps() {
         /* Get the slab region, since that's where we'll be working. */
         const KMemoryRegion &slab_region = KMemoryLayout::GetSlabRegion();
@@ -241,3 +227,33 @@ namespace ams::kern::init {
     }
 
 }
+
+namespace ams::kern {
+
+    void KPageBufferSlabHeap::Initialize(KDynamicPageManager &allocator) {
+        /* Get slab resource counts. */
+        const auto &counts = init::GetSlabResourceCounts();
+
+        /* If size is correct, account for thread local pages. */
+        if (BufferSize == PageSize) {
+            s_buffer_count += counts.num_KProcess + counts.num_KThread + (counts.num_KProcess + counts.num_KThread) / 8;
+        }
+
+        /* Set our object size. */
+        m_obj_size = BufferSize;
+
+        /* Initialize the base allocator. */
+        KSlabHeapImpl::Initialize();
+
+        /* Allocate the desired page count. */
+        for (size_t i = 0; i < s_buffer_count; ++i) {
+            /* Allocate an appropriate buffer. */
+            auto * const pb = (BufferSize <= PageSize) ? allocator.Allocate() : allocator.Allocate(BufferSize / PageSize);
+            MESOSPHERE_ABORT_UNLESS(pb != nullptr);
+
+            /* Free to our slab. */
+            KSlabHeapImpl::Free(pb);
+        }
+    }
+
+}

libraries/libmesosphere/source/kern_k_dump_object.cpp

@@ -332,7 +332,6 @@ namespace ams::kern::KDumpObject {
                     MESOSPHERE_RELEASE_LOG(#__OBJECT__ "\n");                                                                                                                                             \
                     MESOSPHERE_RELEASE_LOG("    Cur=%3zu Peak=%3zu Max=%3zu\n", __OBJECT__::GetSlabHeapSize() - __OBJECT__::GetNumRemaining(), __OBJECT__::GetPeakIndex(), __OBJECT__::GetSlabHeapSize())
 
-                DUMP_KSLABOBJ(KPageBuffer);
                 DUMP_KSLABOBJ(KEvent);
                 DUMP_KSLABOBJ(KInterruptEvent);
                 DUMP_KSLABOBJ(KProcess);

libraries/libmesosphere/source/kern_k_memory_layout.cpp

@@ -127,7 +127,7 @@ namespace ams::kern {
     }
 
     size_t KMemoryLayout::GetResourceRegionSizeForInit(bool use_extra_resource) {
-        return KernelResourceSize + (use_extra_resource ? KernelSlabHeapAdditionalSize : 0);
+        return KernelResourceSize + KSystemControl::SecureAppletMemorySize + (use_extra_resource ? KernelSlabHeapAdditionalSize + KernelPageBufferAdditionalSize : 0);
     }
 
 }

libraries/libmesosphere/source/kern_k_server_session.cpp

@@ -88,6 +88,10 @@ namespace ams::kern {
                     return m_recv_list_count > ipc::MessageBuffer::MessageHeader::ReceiveListCountType_CountOffset;
                 }
 
+                constexpr ALWAYS_INLINE bool IsToMessageBuffer() const {
+                    return m_recv_list_count == ipc::MessageBuffer::MessageHeader::ReceiveListCountType_ToMessageBuffer;
+                }
+
                 void GetBuffer(uintptr_t &out, size_t size, int &key) const {
                     switch (m_recv_list_count) {
                         case ipc::MessageBuffer::MessageHeader::ReceiveListCountType_None:
@@ -264,12 +268,12 @@ namespace ams::kern {
                                                                                          static_cast<KMemoryPermission>(KMemoryPermission_NotMapped | KMemoryPermission_KernelReadWrite),
                                                                                          KMemoryAttribute_Uncached | KMemoryAttribute_Locked, KMemoryAttribute_Locked,
                                                                                          src_pointer,
-                                                                                         KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                                         KMemoryState_FlagLinearMapped, KMemoryState_FlagLinearMapped,
                                                                                          KMemoryPermission_UserRead,
                                                                                          KMemoryAttribute_Uncached, KMemoryAttribute_None));
                 } else {
                     R_TRY(src_page_table.CopyMemoryFromLinearToUser(recv_pointer, recv_size, src_pointer,
-                                                                    KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                    KMemoryState_FlagLinearMapped, KMemoryState_FlagLinearMapped,
                                                                     KMemoryPermission_UserRead,
                                                                     KMemoryAttribute_Uncached, KMemoryAttribute_None));
                 }
@@ -642,12 +646,15 @@ namespace ams::kern {
                     const size_t max_fast_size = std::min<size_t>(offset_words + raw_size, PageSize);
                     const size_t fast_size     = max_fast_size - offset_words;
 
+                    /* Determine source state; if user buffer, we require heap, and otherwise only linear mapped (to enable tls use). */
+                    const auto src_state = src_user ? KMemoryState_FlagReferenceCounted : KMemoryState_FlagLinearMapped;
+
                     /* Determine the source permission. User buffer should be unmapped + read, TLS should be user readable. */
                     const KMemoryPermission src_perm = static_cast<KMemoryPermission>(src_user ? KMemoryPermission_NotMapped | KMemoryPermission_KernelRead : KMemoryPermission_UserRead);
 
                     /* Perform the fast part of the copy. */
                     R_TRY(src_page_table.CopyMemoryFromLinearToKernel(reinterpret_cast<uintptr_t>(dst_msg_ptr) + offset_words, fast_size, src_message_buffer + offset_words,
-                                                                      KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                      src_state, src_state,
                                                                       src_perm,
                                                                       KMemoryAttribute_Uncached, KMemoryAttribute_None));
 
@@ -658,7 +665,7 @@ namespace ams::kern {
                                                                       static_cast<KMemoryPermission>(KMemoryPermission_NotMapped | KMemoryPermission_KernelReadWrite),
                                                                       KMemoryAttribute_Uncached | KMemoryAttribute_Locked, KMemoryAttribute_Locked,
                                                                       src_message_buffer + max_fast_size,
-                                                                      KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                      src_state, src_state,
                                                                       src_perm,
                                                                       KMemoryAttribute_Uncached, KMemoryAttribute_None));
                     }
@@ -744,9 +751,11 @@ namespace ams::kern {
                 R_UNLESS(recv_pointer != 0, svc::ResultOutOfResource());
 
                 /* Perform the pointer data copy. */
-                const KMemoryPermission dst_perm = static_cast<KMemoryPermission>(dst_user ? KMemoryPermission_NotMapped | KMemoryPermission_KernelReadWrite : KMemoryPermission_UserReadWrite);
+                const bool dst_heap  = dst_user && dst_recv_list.IsToMessageBuffer();
+                const auto dst_state = dst_heap ? KMemoryState_FlagReferenceCounted : KMemoryState_FlagLinearMapped;
+                const KMemoryPermission dst_perm = static_cast<KMemoryPermission>(dst_heap ? KMemoryPermission_NotMapped | KMemoryPermission_KernelReadWrite : KMemoryPermission_UserReadWrite);
                 R_TRY(dst_page_table.CopyMemoryFromUserToLinear(recv_pointer, recv_size,
-                                                                KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                dst_state, dst_state,
                                                                 dst_perm,
                                                                 KMemoryAttribute_Uncached, KMemoryAttribute_None,
                                                                 src_pointer));
@@ -898,12 +907,15 @@ namespace ams::kern {
                         const size_t max_fast_size = std::min<size_t>(offset_words + raw_size, PageSize);
                         const size_t fast_size     = max_fast_size - offset_words;
 
+                        /* Determine dst state; if user buffer, we require heap, and otherwise only linear mapped (to enable tls use). */
+                        const auto dst_state = dst_user ? KMemoryState_FlagReferenceCounted : KMemoryState_FlagLinearMapped;
+
                         /* Determine the dst permission. User buffer should be unmapped + read, TLS should be user readable. */
                         const KMemoryPermission dst_perm = static_cast<KMemoryPermission>(dst_user ? KMemoryPermission_NotMapped | KMemoryPermission_KernelReadWrite : KMemoryPermission_UserReadWrite);
 
                         /* Perform the fast part of the copy. */
                         R_TRY(dst_page_table.CopyMemoryFromKernelToLinear(dst_message_buffer + offset_words, fast_size,
-                                                                          KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                          dst_state, dst_state,
                                                                           dst_perm,
                                                                           KMemoryAttribute_Uncached, KMemoryAttribute_None,
                                                                           reinterpret_cast<uintptr_t>(src_msg_ptr) + offset_words));
@@ -911,7 +923,7 @@ namespace ams::kern {
                         /* If the fast part of the copy didn't get everything, perform the slow part of the copy. */
                         if (fast_size < raw_size) {
                             R_TRY(dst_page_table.CopyMemoryFromHeapToHeap(dst_page_table, dst_message_buffer + max_fast_size, raw_size - fast_size,
-                                                                          KMemoryState_FlagReferenceCounted, KMemoryState_FlagReferenceCounted,
+                                                                          dst_state, dst_state,
                                                                           dst_perm,
                                                                           KMemoryAttribute_Uncached, KMemoryAttribute_None,
                                                                           src_message_buffer + max_fast_size,

libraries/libmesosphere/source/kern_k_system_resource.cpp

@@ -42,7 +42,7 @@ namespace ams::kern {
         R_UNLESS(m_resource_size > rc_size, svc::ResultOutOfMemory());
 
         /* Initialize slab heaps. */
-        m_dynamic_page_manager.Initialize(m_resource_address + rc_size, m_resource_size - rc_size);
+        m_dynamic_page_manager.Initialize(m_resource_address + rc_size, m_resource_size - rc_size, PageSize);
         m_page_table_heap.Initialize(std::addressof(m_dynamic_page_manager), 0, GetPointer<KPageTableManager::RefCount>(m_resource_address));
         m_memory_block_heap.Initialize(std::addressof(m_dynamic_page_manager), 0);
         m_block_info_heap.Initialize(std::addressof(m_dynamic_page_manager), 0);

libraries/libmesosphere/source/kern_k_thread.cpp

@@ -46,7 +46,7 @@ namespace ams::kern {
             MESOSPHERE_R_ABORT_UNLESS(Kernel::GetKernelPageTable().UnmapPages(stack_bottom, 1, KMemoryState_Kernel));
 
             /* Free the stack page. */
-            KPageBuffer::Free(KPageBuffer::FromPhysicalAddress(stack_paddr));
+            KPageBuffer::FreeChecked<PageSize>(KPageBuffer::FromPhysicalAddress(stack_paddr));
         }
 
         class ThreadQueueImplForKThreadSleep final : public KThreadQueueWithoutEndWait { /* ... */ };
@@ -334,7 +334,7 @@ namespace ams::kern {
         MESOSPHERE_ABORT_UNLESS(stack_region.GetEndAddress() != 0);
 
         /* Allocate a page to use as the thread. */
-        KPageBuffer *page = KPageBuffer::Allocate();
+        KPageBuffer *page = KPageBuffer::AllocateChecked<PageSize>();
         R_UNLESS(page != nullptr, svc::ResultOutOfResource());
 
         /* Map the stack page. */

libraries/libmesosphere/source/kern_k_thread_local_page.cpp

@@ -24,7 +24,7 @@ namespace ams::kern {
         m_owner = process;
 
         /* Allocate a new page. */
-        KPageBuffer *page_buf = KPageBuffer::Allocate();
+        KPageBuffer *page_buf = KPageBuffer::AllocateChecked<PageSize>();
         R_UNLESS(page_buf != nullptr, svc::ResultOutOfMemory());
         ON_RESULT_FAILURE { KPageBuffer::Free(page_buf); };
 
@@ -43,7 +43,7 @@ namespace ams::kern {
         R_TRY(m_owner->GetPageTable().UnmapPages(this->GetAddress(), 1, KMemoryState_ThreadLocal));
 
         /* Free the page. */
-        KPageBuffer::Free(KPageBuffer::FromPhysicalAddress(phys_addr));
+        KPageBuffer::FreeChecked<PageSize>(KPageBuffer::FromPhysicalAddress(phys_addr));
         R_SUCCEED();
     }
 

libraries/libmesosphere/source/kern_kernel.cpp

@@ -75,7 +75,10 @@ namespace ams::kern {
         size -= rc_size;
 
         /* Initialize the resource managers' shared page manager. */
-        g_resource_manager_page_manager.Initialize(address, size);
+        g_resource_manager_page_manager.Initialize(address, size, std::max<size_t>(PageSize, KPageBufferSlabHeap::BufferSize));
+
+        /* Initialize the KPageBuffer slab heap. */
+        KPageBuffer::InitializeSlabHeap(g_resource_manager_page_manager);
 
         /* Initialize the fixed-size slabheaps. */
         s_app_memory_block_heap.Initialize(std::addressof(g_resource_manager_page_manager), ApplicationMemoryBlockSlabHeapSize);
@@ -143,6 +146,9 @@ namespace ams::kern {
         PrintMemoryRegion("    KernelRegion",       KMemoryLayout::GetKernelRegionPhysicalExtents());
         PrintMemoryRegion("        Code",           KMemoryLayout::GetKernelCodeRegionPhysicalExtents());
         PrintMemoryRegion("        Slab",           KMemoryLayout::GetKernelSlabRegionPhysicalExtents());
+        if constexpr (KSystemControl::SecureAppletMemorySize > 0) {
+            PrintMemoryRegion("        SecureApplet", KMemoryLayout::GetKernelSecureAppletMemoryRegionPhysicalExtents());
+        }
         PrintMemoryRegion("        PageTableHeap",  KMemoryLayout::GetKernelPageTableHeapRegionPhysicalExtents());
         PrintMemoryRegion("        InitPageTable",  KMemoryLayout::GetKernelInitPageTableRegionPhysicalExtents());
         if constexpr (IsKTraceEnabled) {

libraries/libmesosphere/source/kern_main.cpp

@@ -58,7 +58,6 @@ namespace ams::kern {
                 MESOSPHERE_ABORT_UNLESS(management_region.GetEndAddress() != 0);
 
                 Kernel::GetMemoryManager().Initialize(management_region.GetAddress(), management_region.GetSize());
-                init::InitializeKPageBufferSlabHeap();
             }
 
             /* Copy the Initial Process Binary to safe memory. */

mesosphere/kernel/source/arch/arm64/init/kern_init_core.cpp

@@ -418,12 +418,18 @@ namespace ams::kern::init {
         /* NOTE: Nintendo does this only on 10.0.0+ */
         init_pt.PhysicallyRandomize(slab_region_start, slab_region_size, false);
 
+        /* Insert a physical region for the secure applet memory. */
+        const auto secure_applet_end_phys_addr = slab_end_phys_addr + KSystemControl::SecureAppletMemorySize;
+        if constexpr (KSystemControl::SecureAppletMemorySize > 0) {
+            MESOSPHERE_INIT_ABORT_UNLESS(KMemoryLayout::GetPhysicalMemoryRegionTree().Insert(GetInteger(slab_end_phys_addr), KSystemControl::SecureAppletMemorySize, KMemoryRegionType_DramKernelSecureAppletMemory));
+        }
+
         /* Determine size available for kernel page table heaps. */
         const KPhysicalAddress resource_end_phys_addr = slab_start_phys_addr + resource_region_size;
-        const size_t page_table_heap_size = GetInteger(resource_end_phys_addr) - GetInteger(slab_end_phys_addr);
+        const size_t page_table_heap_size = GetInteger(resource_end_phys_addr) - GetInteger(secure_applet_end_phys_addr);
 
         /* Insert a physical region for the kernel page table heap region */
-        MESOSPHERE_INIT_ABORT_UNLESS(KMemoryLayout::GetPhysicalMemoryRegionTree().Insert(GetInteger(slab_end_phys_addr), page_table_heap_size, KMemoryRegionType_DramKernelPtHeap));
+        MESOSPHERE_INIT_ABORT_UNLESS(KMemoryLayout::GetPhysicalMemoryRegionTree().Insert(GetInteger(secure_applet_end_phys_addr), page_table_heap_size, KMemoryRegionType_DramKernelPtHeap));
 
         /* All DRAM regions that we haven't tagged by this point will be mapped under the linear mapping. Tag them. */
         for (auto &region : KMemoryLayout::GetPhysicalMemoryRegionTree()) {