kernel/acpi: implement basic table discovery

3 files changed, 89 insertions, 3 deletions

diff --git a/kernel/include/kernel/acpi/manager.hpp b/kernel/include/kernel/acpi/manager.hpp
index fc76685..437d4c8 100644
--- a/kernel/include/kernel/acpi/manager.hpp
+++ b/kernel/include/kernel/acpi/manager.hpp
@@ -3,8 +3,11 @@
 
 #include "kapi/acpi.hpp"
 
+#include <kstd/flat_map>
 #include <kstd/vector>
 
+#include <string_view>
+
 namespace kernel::acpi
 {
 
@@ -17,7 +20,7 @@ namespace kernel::acpi
   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{};
+    kstd::flat_map<std::string_view, kapi::acpi::system_description_table_header const *> m_tables{};
     bool m_extended{};
   };
 
diff --git a/kernel/kapi/acpi.cpp b/kernel/kapi/acpi.cpp
index 787bcff..998d7a0 100644
--- a/kernel/kapi/acpi.cpp
+++ b/kernel/kapi/acpi.cpp
@@ -65,6 +65,51 @@ namespace kapi::acpi
     return validate_checksum({reinterpret_cast<std::byte const *>(this), m_length});
   }
 
+  [[nodiscard]] auto system_description_table_header::checksum() const noexcept -> std::uint8_t
+  {
+    return m_checksum;
+  }
+
+  [[nodiscard]] auto system_description_table_header::creator_revision() const noexcept -> std::uint32_t
+  {
+    return m_creator_revision;
+  }
+
+  [[nodiscard]] auto system_description_table_header::creator_id() const noexcept -> std::uint32_t
+  {
+    return m_creator_id;
+  }
+
+  [[nodiscard]] auto system_description_table_header::length() const noexcept -> kstd::units::bytes
+  {
+    return kstd::units::bytes{m_length};
+  }
+
+  [[nodiscard]] auto system_description_table_header::oem_id() const noexcept -> std::string_view
+  {
+    return {m_oem_id.data(), m_oem_id.size()};
+  }
+
+  [[nodiscard]] auto system_description_table_header::oem_revision() const noexcept -> std::uint32_t
+  {
+    return m_oem_revision;
+  }
+
+  [[nodiscard]] auto system_description_table_header::oem_table_id() const noexcept -> std::string_view
+  {
+    return {m_oem_table_id.data(), m_oem_table_id.size()};
+  }
+
+  [[nodiscard]] auto system_description_table_header::revision() const noexcept -> std::uint8_t
+  {
+    return m_revision;
+  }
+
+  [[nodiscard]] auto system_description_table_header::signature() const noexcept -> std::string_view
+  {
+    return {m_signature.data(), m_signature.size()};
+  }
+
   auto init(root_system_description_pointer const & sdp) -> bool
   {
     auto static constinit initialized = std::atomic_flag{};
diff --git a/kernel/src/acpi/manager.cpp b/kernel/src/acpi/manager.cpp
index 6a17920..180d458 100644
--- a/kernel/src/acpi/manager.cpp
+++ b/kernel/src/acpi/manager.cpp
@@ -4,7 +4,10 @@
 #include "kapi/memory.hpp"
 #include "kapi/system.hpp"
 
+#include <kstd/print>
+
 #include <cstddef>
+#include <cstdint>
 
 namespace kernel::acpi
 {
@@ -43,12 +46,47 @@ namespace kernel::acpi
 
   auto manager::load_tables() -> bool
   {
-    if (!kapi::acpi::validate_checksum({reinterpret_cast<std::byte const *>(m_rsdt), m_rsdt->length}))
+    if (!kapi::acpi::validate_checksum({reinterpret_cast<std::byte const *>(m_rsdt), m_rsdt->length().value}))
     {
       kapi::system::panic("[OS:ACPI] Invalid RSDT checksum!");
     }
 
-    return false;
+    auto entry_size = m_extended ? sizeof(std::uint64_t) : sizeof(std::uint32_t);
+    auto entry_count = (m_rsdt->length().value - sizeof(kapi::acpi::system_description_table_header)) / entry_size;
+    auto entries_base =
+        reinterpret_cast<std::byte const *>(m_rsdt) + sizeof(kapi::acpi::system_description_table_header);
+
+    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<kapi::acpi::system_description_table_header const *>(linear_table_address);
+
+      if (!kapi::acpi::validate_checksum({reinterpret_cast<std::byte const *>(table), table->length().value}))
+      {
+        kstd::println(kstd::print_sink::stderr, "[OS:ACPI] Invalid table checksum!");
+      }
+      else
+      {
+        kstd::println("[OS:ACPI] Found table: {}@{:#x}/{:#x} OEM: {} Rev: {}", table->signature(), linear_table_address,
+                      physical_table_address, table->oem_id(), table->creator_revision());
+        m_tables.emplace(table->signature(), table);
+      }
+    }
+
+    return !m_tables.empty();
   }
 
 }  // namespace kernel::acpi