From 776ab2749d5af0a34fd2aa6103a377ddc04d4c53 Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Thu, 16 Apr 2026 10:03:35 +0200
Subject: acpi: introduce XSDT type

---
 kernel/src/acpi/manager.cpp | 44 +++++++++++++++++++++-----------------------
 1 file changed, 21 insertions(+), 23 deletions(-)

(limited to 'kernel')

diff --git a/kernel/src/acpi/manager.cpp b/kernel/src/acpi/manager.cpp
index 2f2a1bd..5876799 100644
--- a/kernel/src/acpi/manager.cpp
+++ b/kernel/src/acpi/manager.cpp
@@ -8,8 +8,10 @@
 
 #include <acpi/acpi.hpp>
 
+#include <algorithm>
 #include <cstddef>
 #include <cstdint>
+#include <ranges>
 #include <string_view>
 
 namespace kernel::acpi
@@ -32,7 +34,7 @@ namespace kernel::acpi
       }
       auto physical_extended_table_address = kapi::memory::physical_address{xsdp->table_address()};
       auto linear_extended_table_address = kapi::memory::hhdm_to_linear(physical_extended_table_address);
-      m_rsdt = static_cast<::acpi::table_header const *>(linear_extended_table_address);
+      m_rsdt = static_cast<::acpi::xsdt const *>(linear_extended_table_address);
       m_extended = true;
     }
     else
@@ -54,29 +56,12 @@ namespace kernel::acpi
       kapi::system::panic("[OS:ACPI] Invalid RSDT checksum!");
     }
 
-    auto entry_size = m_extended ? sizeof(std::uint64_t) : sizeof(std::uint32_t);
-    auto entry_count = (m_rsdt->length().value - sizeof(::acpi::table_header)) / entry_size;
-    auto entries_base = reinterpret_cast<std::byte const *>(m_rsdt) + sizeof(::acpi::table_header);
+    auto check_and_register_table = [&](auto table_address) -> void {
+      auto physical_table_address = kapi::memory::physical_address{reinterpret_cast<std::uintptr_t>(table_address)};
+      auto mapped_table = kapi::memory::hhdm_to_linear(physical_table_address);
+      auto table = static_cast<::acpi::table_header const *>(mapped_table);
 
-    for (std::size_t i = 0; i < entry_count; ++i)
-    {
-      auto physical_table_address = kapi::memory::physical_address{};
-
-      if (m_extended)
-      {
-        auto entry = reinterpret_cast<std::uint64_t const *>(entries_base + (i * entry_size));
-        physical_table_address = kapi::memory::physical_address{*entry};
-      }
-      else
-      {
-        auto entry = reinterpret_cast<std::uint32_t const *>(entries_base + (i * entry_size));
-        physical_table_address = kapi::memory::physical_address{*entry};
-      }
-
-      auto linear_table_address = kapi::memory::hhdm_to_linear(physical_table_address);
-      auto table = static_cast<::acpi::table_header const *>(linear_table_address);
-
-      if (!::acpi::validate_checksum({reinterpret_cast<std::byte const *>(table), table->length().value}))
+      if (!::acpi::validate_checksum({static_cast<std::byte const *>(mapped_table), table->length().value}))
       {
         kstd::println(kstd::print_sink::stderr, "[OS:ACPI] Invalid table checksum!");
       }
@@ -85,6 +70,19 @@ namespace kernel::acpi
         kstd::println("[OS:ACPI] Found '{}' ACPI table", table->signature());
         m_tables.emplace(table->signature(), table);
       }
+    };
+
+    if (m_extended)
+    {
+      auto xsdt = static_cast<::acpi::xsdt const *>(m_rsdt);
+      std::ranges::for_each(*xsdt | std::views::transform([](auto const & entry) { return entry.address(); }),
+                            check_and_register_table);
+    }
+    else
+    {
+      auto rsdt = static_cast<::acpi::rsdt const *>(m_rsdt);
+      std::ranges::for_each(*rsdt | std::views::transform([](auto const & entry) { return entry.address(); }),
+                            check_and_register_table);
     }
 
     return !m_tables.empty();
-- 
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