1 files changed, 23 insertions, 26 deletions

diff --git a/arch/x86_64/kapi/platform.cpp b/arch/x86_64/kapi/platform.cpp
index 4ee35c7..fb27329 100644
--- a/arch/x86_64/kapi/platform.cpp
+++ b/arch/x86_64/kapi/platform.cpp
@@ -8,57 +8,54 @@
 #include <kstd/memory>
 #include <kstd/print>
 
-#include <cstddef>
+#include <ranges>
 #include <utility>
 
 namespace kapi::platform
 {
+  namespace
+  {
+    constexpr auto candidate_flags = acpi::processor_local_apic::flags::processor_enabled  //
+                                     | acpi::processor_local_apic::flags::online_capable;
+  }
 
   auto discover_cpu_topology(kapi::devices::bus & bus) -> bool
   {
     auto static const core_major = kapi::devices::allocate_major_number();
     auto static const interrupt_controller_major = kapi::devices::allocate_major_number();
 
-    auto madt = kapi::acpi::get_table("APIC");
+    auto madt = kapi::acpi::get_table<acpi::madt_table_signature>();
     if (!madt)
     {
       kstd::println("[x86_64:PLT] Failed to find ACPI APIC table");
       return false;
     }
 
-    auto real_madt = static_cast<acpi::madt_header const *>(madt.get());
-    auto current = reinterpret_cast<std::byte const *>(madt.get()) + sizeof(kapi::acpi::madt_header);
-    auto end = reinterpret_cast<std::byte const *>(madt.get()) + madt->length();
-
     auto bsp_found = false;
     auto core_count = 0uz;
+    auto local_apic_address = madt->local_interrupt_controller_address();
 
-    while (current < end)
+    auto lapic_entries = *madt | std::views::filter([](auto const & entry) {
+      return entry.type() == acpi::multiple_apic_description_table_entry::types::processor_local_apic;
+    }) | std::views::transform([](auto const & entry) {
+      return static_cast<acpi::processor_local_apic const &>(entry);
+    }) | std::views::filter([](auto const & entry) {
+      return static_cast<bool>(entry.active_flags() & candidate_flags);
+    });
+
+    for (auto const & apic : lapic_entries)
     {
-      auto const * sub_table = reinterpret_cast<kapi::acpi::madt_subtable_header const *>(current);
-      if (sub_table->type() == 0)
+      auto is_bsp = !bsp_found;
+      bsp_found = true;
+      auto instance = kstd::make_unique<arch::devices::local_apic>(interrupt_controller_major, core_count,
+                                                                   apic.apic_id(), local_apic_address, is_bsp);
+      if (kapi::platform::cpu_detected(bus, core_major, core_count, apic.processor_id(), is_bsp, std::move(instance)))
       {
-        auto const * local_apic = reinterpret_cast<kapi::acpi::madt_local_apic const *>(sub_table);
-        if (local_apic->flags() & 0b11)
-        {
-          auto is_bsp = !bsp_found;
-          bsp_found = true;
-          auto lapic = kstd::make_unique<arch::devices::local_apic>(
-              interrupt_controller_major, core_count, local_apic->apic_id(),
-              real_madt->local_interrupt_controller_address(), is_bsp);
-          if (kapi::platform::cpu_detected(bus, core_major, core_count, local_apic->processor_id(), is_bsp,
-                                           std::move(lapic)))
-          {
-            ++core_count;
-          }
-        }
+        ++core_count;
       }
-
-      current += sub_table->length();
     }
 
     kstd::println("[x86_64:PLT] Found {} CPU cores", core_count);
-
     return core_count > 0;
   }