From f0acad6f3206079d804b2f59aace0dc32dbeb6dc Mon Sep 17 00:00:00 2001
From: Amlal El Mahrouss <amlal@nekernel.org>
Date: Thu, 19 Feb 2026 08:14:48 +0100
Subject: kernel: lots of tweaks and improvements, WIP: ASN, FileMgr support
 for OpenHeFS.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>
---
 src/kernel/HALKit/ARM64/HalPagingMgr.cpp | 81 ++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 src/kernel/HALKit/ARM64/HalPagingMgr.cpp

(limited to 'src/kernel/HALKit/ARM64/HalPagingMgr.cpp')

diff --git a/src/kernel/HALKit/ARM64/HalPagingMgr.cpp b/src/kernel/HALKit/ARM64/HalPagingMgr.cpp
new file mode 100644
index 00000000..0fe4d759
--- /dev/null
+++ b/src/kernel/HALKit/ARM64/HalPagingMgr.cpp
@@ -0,0 +1,81 @@
+// Copyright 2024-2025, Amlal El Mahrouss (amlal@nekernel.org)
+// Licensed under the Apache License, Version 2.0 (see LICENSE file)
+// Official repository: https://github.com/nekernel-org/nekernel
+
+#include <HALKit/ARM64/Paging.h>
+#include <HALKit/ARM64/Processor.h>
+
+namespace Kernel::HAL {
+typedef UInt32 PageTableIndex;
+
+EXTERN_C UIntPtr mm_get_page_addr(VoidPtr virtual_address) {
+  if (!virtual_address) return 0;
+
+  UInt64 ttbr0_val = 0;
+
+  asm volatile("mrs %0, ttbr0_el1" : "=r"(ttbr0_val));
+  volatile UInt64* l1_table = reinterpret_cast<volatile UInt64*>(ttbr0_val);
+
+  UInt64 l1_idx = (reinterpret_cast<UIntPtr>(virtual_address) >> 39) & 0x1FF;
+  UInt64 l2_idx = (reinterpret_cast<UIntPtr>(virtual_address) >> 30) & 0x1FF;
+  UInt64 l3_idx = (reinterpret_cast<UIntPtr>(virtual_address) >> 21) & 0x1FF;
+
+  if (!l1_table[l1_idx]) return 0;
+
+  volatile UInt64* l2_table = reinterpret_cast<volatile UInt64*>(l1_table[l1_idx] & ~0xFFFUL);
+
+  if (!l2_table[l2_idx]) return 0;
+
+  volatile UInt64* l3_table = reinterpret_cast<volatile UInt64*>(l2_table[l2_idx] & ~0xFFFUL);
+
+  if (!l3_table[l3_idx]) return 0;
+
+  return (l3_table[l3_idx] & ~0xFFFUL);
+}
+
+/// @brief Maps or allocates a page from virtual_address.
+/// @param virtual_address a valid virtual address.
+/// @param phys_addr point to physical address.
+/// @param flags the flags to put on the page.
+/// @return Status code of page manipulation process.
+EXTERN_C Int32 mm_map_page(VoidPtr virtual_address, VoidPtr physical_address, UInt32 flags,
+                           UInt32 level) {
+  if (!virtual_address || !flags || !physical_address) return kErrorInvalidData;
+
+  UInt64 ttbr0_val = 0;
+
+  asm volatile("mrs %0, ttbr0_el1" : "=r"(ttbr0_val));
+  volatile UInt64* l1_table = reinterpret_cast<volatile UInt64*>(ttbr0_val);
+
+  UInt64 l1_idx = (reinterpret_cast<UIntPtr>(virtual_address) >> 39) & 0x1FF;
+  UInt64 l2_idx = (reinterpret_cast<UIntPtr>(virtual_address) >> 30) & 0x1FF;
+  UInt64 l3_idx = (reinterpret_cast<UIntPtr>(virtual_address) >> 21) & 0x1FF;
+
+  if (!l1_table[l1_idx]) return kErrorInvalidData;
+
+  volatile UInt64* l2_table = reinterpret_cast<volatile UInt64*>(l1_table[l1_idx] & ~0xFFFUL);
+
+  if (!l2_table[l2_idx]) return kErrorInvalidData;
+
+  volatile UInt64* l3_table = reinterpret_cast<volatile UInt64*>(l2_table[l2_idx] & ~0xFFFUL);
+
+  l3_table[l3_idx] = (reinterpret_cast<UInt64>(physical_address) & ~0xFFFUL) | flags;
+
+  switch (level) {
+    case 2: {
+      l3_table[l3_idx] = (reinterpret_cast<UInt64>(physical_address) & ~0xFFFUL) | flags;
+      return kErrorSuccess;
+    }
+    case 1: {
+      l1_table[l1_idx] = (reinterpret_cast<UInt64>(physical_address) & ~0xFFFUL) | flags;
+      return kErrorSuccess;
+    }
+    case 0: {
+      l1_table[l1_idx] = (reinterpret_cast<UInt64>(physical_address) & ~0xFFFUL) | flags;
+      return kErrorSuccess;
+    }
+  }
+
+  return kErrorInvalidData;
+}
+}  // namespace Kernel::HAL
-- 
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