kernel/acpi: implement basic table discovery

1 files changed, 40 insertions, 2 deletions

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