From 3dcd14a0570fef3bcc68d7df42fe3ff4cd496f93 Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Mon, 6 Apr 2026 14:47:37 +0200
Subject: kapi: hook ACPI initialization up to boot process

---
 kernel/CMakeLists.txt                  |  1 +
 kernel/include/kernel/acpi/manager.hpp | 26 ++++++++++++++++
 kernel/kapi/acpi.cpp                   | 32 ++++++++++++++++----
 kernel/src/acpi/manager.cpp            | 54 ++++++++++++++++++++++++++++++++++
 4 files changed, 107 insertions(+), 6 deletions(-)
 create mode 100644 kernel/include/kernel/acpi/manager.hpp
 create mode 100644 kernel/src/acpi/manager.cpp

(limited to 'kernel')

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index ab77467..fc01723 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -14,6 +14,7 @@ add_library("kernel_objs" OBJECT
     "kstd/print.cpp"
 
     # Kernel Implementation
+    "src/acpi/manager.cpp"
     "src/memory/bitmap_allocator.cpp"
     "src/memory/block_list_allocator.cpp"
     "src/memory.cpp"
diff --git a/kernel/include/kernel/acpi/manager.hpp b/kernel/include/kernel/acpi/manager.hpp
new file mode 100644
index 0000000..fc76685
--- /dev/null
+++ b/kernel/include/kernel/acpi/manager.hpp
@@ -0,0 +1,26 @@
+#ifndef TEACHOS_KERNEL_ACPI_MANAGER_HPP
+#define TEACHOS_KERNEL_ACPI_MANAGER_HPP
+
+#include "kapi/acpi.hpp"
+
+#include <kstd/vector>
+
+namespace kernel::acpi
+{
+
+  struct manager
+  {
+    explicit manager(kapi::acpi::root_system_description_pointer const & sdp);
+
+    auto load_tables() -> bool;
+
+  private:
+    kapi::acpi::root_system_description_pointer const * m_sdp{};
+    kapi::acpi::system_description_table_header const * m_rsdt{};
+    kstd::vector<kapi::acpi::system_description_table_header> m_tables{};
+    bool m_extended{};
+  };
+
+}  // namespace kernel::acpi
+
+#endif
diff --git a/kernel/kapi/acpi.cpp b/kernel/kapi/acpi.cpp
index aa0066d..787bcff 100644
--- a/kernel/kapi/acpi.cpp
+++ b/kernel/kapi/acpi.cpp
@@ -1,13 +1,18 @@
 #include "kapi/acpi.hpp"
 
 #include "kapi/memory.hpp"
+#include "kapi/system.hpp"
+
+#include "kernel/acpi/manager.hpp"
 
 #include <kstd/units>
 
 #include <algorithm>
+#include <atomic>
 #include <bit>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 #include <span>
 #include <string_view>
 
@@ -16,12 +21,7 @@ namespace kapi::acpi
 
   namespace
   {
-    constexpr auto validate_checksum(std::span<std::byte const> data) -> bool
-    {
-      auto sum = std::ranges::fold_left(
-          data, std::uint8_t{}, [](std::uint8_t acc, auto byte) { return static_cast<std::uint8_t>(byte) + acc; });
-      return sum == 0;
-    }
+    auto constinit manager = std::optional<kernel::acpi::manager>{};
   }  // namespace
 
   auto root_system_description_pointer::oem_id() const noexcept -> std::string_view
@@ -65,4 +65,24 @@ namespace kapi::acpi
     return validate_checksum({reinterpret_cast<std::byte const *>(this), m_length});
   }
 
+  auto init(root_system_description_pointer const & sdp) -> bool
+  {
+    auto static constinit initialized = std::atomic_flag{};
+    if (initialized.test_and_set())
+    {
+      system::panic("[OS::ACPI] The ACPI manager has already been initialized!");
+    }
+
+    manager.emplace(sdp);
+    return manager->load_tables();
+  }
+
+  auto validate_checksum(std::span<std::byte const> data) -> bool
+  {
+    auto sum = std::ranges::fold_left(data, std::uint8_t{}, [](auto acc, auto byte) {
+      return static_cast<std::uint8_t>(acc + static_cast<std::uint8_t>(byte));
+    });
+    return sum == 0;
+  }
+
 };  // namespace kapi::acpi
diff --git a/kernel/src/acpi/manager.cpp b/kernel/src/acpi/manager.cpp
new file mode 100644
index 0000000..6a17920
--- /dev/null
+++ b/kernel/src/acpi/manager.cpp
@@ -0,0 +1,54 @@
+#include "kernel/acpi/manager.hpp"
+
+#include "kapi/acpi.hpp"
+#include "kapi/memory.hpp"
+#include "kapi/system.hpp"
+
+#include <cstddef>
+
+namespace kernel::acpi
+{
+
+  manager::manager(kapi::acpi::root_system_description_pointer const & sdp)
+      : m_sdp{&sdp}
+  {
+    if (m_sdp->signature() != "RSD PTR ")
+    {
+      kapi::system::panic("[OS:ACPI] Invalid RSDP signature!");
+    }
+
+    if (m_sdp->revision() >= 2)
+    {
+      auto const xsdp = static_cast<kapi::acpi::extended_system_description_pointer const *>(m_sdp);
+      if (!xsdp->validate())
+      {
+        kapi::system::panic("[OS:ACPI] Invalid XSDP signature!");
+      }
+      auto physical_extended_table_address = xsdp->table_address();
+      auto linear_extended_table_address = kapi::memory::hhdm_to_linear(physical_extended_table_address);
+      m_rsdt = static_cast<kapi::acpi::system_description_table_header const *>(linear_extended_table_address);
+      m_extended = true;
+    }
+    else
+    {
+      if (!m_sdp->validate())
+      {
+        kapi::system::panic("[OS:ACPI] Invalid RSDP checksum!");
+      }
+      auto physical_root_table_address = m_sdp->table_address();
+      auto linear_root_table_address = kapi::memory::hhdm_to_linear(physical_root_table_address);
+      m_rsdt = static_cast<kapi::acpi::system_description_table_header const *>(linear_root_table_address);
+    }
+  }
+
+  auto manager::load_tables() -> bool
+  {
+    if (!kapi::acpi::validate_checksum({reinterpret_cast<std::byte const *>(m_rsdt), m_rsdt->length}))
+    {
+      kapi::system::panic("[OS:ACPI] Invalid RSDT checksum!");
+    }
+
+    return false;
+  }
+
+}  // namespace kernel::acpi
-- 
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