Kernel/aarch64: Change MMU::kernel_virtual_range to high virtual memory

This was previously hardcoded this to be the physical memory range,
since we identity mapped the memory, however we now run the kernel at
a high virtual memory address.

Also changes PageDirectory.h to store up-to 512 pages, as the code now
needs access to more than 4 pages.

2 files changed, 2 insertions, 7 deletions

diff --git a/Kernel/Memory/MemoryManager.cpp b/Kernel/Memory/MemoryManager.cpp
index 154dba1f77..fb43867104 100644
--- a/Kernel/Memory/MemoryManager.cpp
+++ b/Kernel/Memory/MemoryManager.cpp
@@ -72,9 +72,8 @@ bool MemoryManager::is_initialized()
 static UNMAP_AFTER_INIT VirtualRange kernel_virtual_range()
 {
 #if ARCH(AARCH64)
-    // NOTE: We currently identity map the kernel image for aarch64, so the kernel virtual range
-    //       is the complete memory range.
-    return VirtualRange { VirtualAddress((FlatPtr)0), 0x3F000000 };
+    // NOTE: This is not the same as x86_64, because the aarch64 kernel currently doesn't use the pre-kernel.
+    return VirtualRange { VirtualAddress(kernel_mapping_base), KERNEL_PD_END - kernel_mapping_base };
 #else
     size_t kernel_range_start = kernel_mapping_base + 2 * MiB; // The first 2 MiB are used for mapping the pre-kernel
     return VirtualRange { VirtualAddress(kernel_range_start), KERNEL_PD_END - kernel_range_start };
diff --git a/Kernel/Memory/PageDirectory.h b/Kernel/Memory/PageDirectory.h
index 5ae014464c..dfd707d589 100644
--- a/Kernel/Memory/PageDirectory.h
+++ b/Kernel/Memory/PageDirectory.h
@@ -67,11 +67,7 @@ private:
     RefPtr<PhysicalPage> m_pml4t;
 #endif
     RefPtr<PhysicalPage> m_directory_table;
-#if ARCH(X86_64)
     RefPtr<PhysicalPage> m_directory_pages[512];
-#else
-    RefPtr<PhysicalPage> m_directory_pages[4];
-#endif
     RecursiveSpinlock<LockRank::None> m_lock {};
 };