From b31c47b32d91b0b85245ed30f1751cd5cbc397cf Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Thu, 16 Apr 2026 09:37:41 +0200
Subject: acpi: add rsdt type

---
 libs/acpi/CMakeLists.txt          |  2 ++
 libs/acpi/acpi/data/rsdt.cpp      | 37 +++++++++++++++++++++++++++++++
 libs/acpi/acpi/data/rsdt.hpp      | 42 +++++++++++++++++++++++++++++++++++
 libs/acpi/acpi/data/rsdt.test.cpp | 46 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 127 insertions(+)
 create mode 100644 libs/acpi/acpi/data/rsdt.cpp
 create mode 100644 libs/acpi/acpi/data/rsdt.hpp
 create mode 100644 libs/acpi/acpi/data/rsdt.test.cpp

(limited to 'libs')

diff --git a/libs/acpi/CMakeLists.txt b/libs/acpi/CMakeLists.txt
index f6e484c..833dcea 100644
--- a/libs/acpi/CMakeLists.txt
+++ b/libs/acpi/CMakeLists.txt
@@ -22,6 +22,7 @@ target_sources("acpi" PRIVATE
   "acpi/common/checksum.cpp"
   "acpi/common/table_header.cpp"
   "acpi/data/madt.cpp"
+  "acpi/data/rsdt.cpp"
   "acpi/pointers.cpp"
 )
 
@@ -61,6 +62,7 @@ if(NOT CMAKE_CROSSCOMPILING)
   add_executable("acpi_tests"
     "acpi/common/table_header.test.cpp"
     "acpi/data/madt.test.cpp"
+    "acpi/data/rsdt.test.cpp"
     "acpi/pointers.test.cpp"
 
     "test_data/tables.S"
diff --git a/libs/acpi/acpi/data/rsdt.cpp b/libs/acpi/acpi/data/rsdt.cpp
new file mode 100644
index 0000000..8e20b6c
--- /dev/null
+++ b/libs/acpi/acpi/data/rsdt.cpp
@@ -0,0 +1,37 @@
+#include <kstd/cstring>
+
+#include <acpi/common/table_header.hpp>
+#include <acpi/data/rsdt.hpp>
+
+#include <cstddef>
+#include <cstdint>
+
+namespace acpi
+{
+
+  struct rsdt_entry_data
+  {
+    std::uint32_t address;
+  };
+
+  [[nodiscard]] auto rsdt_entry::address() const noexcept -> table_header *
+  {
+    using type = decltype(rsdt_entry_data::address);
+
+    constexpr auto size = sizeof(type);
+    constexpr auto offset = offsetof(rsdt_entry_data, address);
+
+    auto const data = std::span<std::byte const, size>{m_data.data() + offset, size};
+    auto value = type{};
+
+    kstd::libc::memcpy(&value, data.data(), size);
+
+    return reinterpret_cast<table_header *>(static_cast<uintptr_t>(value));
+  }
+
+  [[nodiscard]] auto rsdt_entry::length() const noexcept -> std::size_t
+  {
+    return sizeof(m_data);
+  }
+
+}  // namespace acpi
\ No newline at end of file
diff --git a/libs/acpi/acpi/data/rsdt.hpp b/libs/acpi/acpi/data/rsdt.hpp
new file mode 100644
index 0000000..b43f066
--- /dev/null
+++ b/libs/acpi/acpi/data/rsdt.hpp
@@ -0,0 +1,42 @@
+#ifndef ACPI_DATA_RSDT_HPP
+#define ACPI_DATA_RSDT_HPP
+
+#include <acpi/acpi.hpp>
+#include <acpi/common/table_signature.hpp>
+#include <acpi/common/table_type.hpp>
+#include <acpi/common/vla_table.hpp>
+
+#include <array>
+#include <cstddef>
+
+namespace acpi
+{
+
+  template<>
+  struct table_signature<struct rsdt>
+  {
+    constexpr char static const value[] = "RSDT";  // NOLINT
+  };
+
+  template<>
+  struct table_type<table_signature_v<struct rsdt>>
+  {
+    using type = struct rsdt;
+  };
+
+  struct rsdt_entry
+  {
+    [[nodiscard]] auto address() const noexcept -> table_header *;
+    [[nodiscard]] auto length() const noexcept -> std::size_t;
+
+  private:
+    std::array<std::byte, 4> m_data{};
+  };
+
+  struct rsdt : vla_table<rsdt_entry, rsdt>
+  {
+  };
+
+}  // namespace acpi
+
+#endif
\ No newline at end of file
diff --git a/libs/acpi/acpi/data/rsdt.test.cpp b/libs/acpi/acpi/data/rsdt.test.cpp
new file mode 100644
index 0000000..e1bd1df
--- /dev/null
+++ b/libs/acpi/acpi/data/rsdt.test.cpp
@@ -0,0 +1,46 @@
+#include <kstd/units>
+
+#include <acpi/acpi.hpp>
+#include <acpi/data/rsdt.hpp>
+#include <catch2/catch_test_macros.hpp>
+#include <test_data/tables.hpp>
+
+#include <iterator>
+
+SCENARIO("RSDT parsing", "[rsdt]")
+{
+  GIVEN("The basic compiled RSDT containing 8 table pointers")
+  {
+    auto data = acpi::test_data::tables::basic_rsdt();
+
+    WHEN("parsing the table")
+    {
+      auto rsdt = reinterpret_cast<acpi::rsdt const *>(data.data());
+
+      THEN("the signature is correct")
+      {
+        REQUIRE(rsdt->signature() == "RSDT");
+      }
+
+      THEN("validate returns true")
+      {
+        REQUIRE(rsdt->validate());
+      }
+
+      THEN("there are 8 entries in the table")
+      {
+        REQUIRE(std::distance(rsdt->begin(), rsdt->end()) == 8);
+      }
+
+      THEN("the first entry has address 0x10")
+      {
+        REQUIRE(rsdt->cbegin()->address() == reinterpret_cast<acpi::table_header *>(0x10));
+      }
+
+      THEN("the length is sizeof(rsdt) + 8 * sizeof(rsdt_entry)")
+      {
+        REQUIRE(rsdt->length() == sizeof(acpi::rsdt) + 8 * sizeof(acpi::rsdt_entry));
+      }
+    }
+  }
+}
-- 
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