3 files changed, 104 insertions, 24 deletions

diff --git a/arch/x86_64/kapi/acpi.cpp b/arch/x86_64/kapi/acpi.cpp
new file mode 100644
index 0000000..ec38aee
--- /dev/null
+++ b/arch/x86_64/kapi/acpi.cpp
@@ -0,0 +1,30 @@
+#include "kapi/acpi.hpp"
+
+#include "arch/boot/boot.hpp"
+
+#include <kstd/memory>
+
+namespace kapi::acpi
+{
+
+  auto get_root_pointer() -> kstd::observer_ptr<root_system_description_pointer const>
+  {
+    auto const & mbi = kapi::boot::bootstrap_information.mbi;
+    auto system_description_pointer = static_cast<kapi::acpi::root_system_description_pointer const *>(nullptr);
+
+    if (auto const & xsdp = mbi->maybe_acpi_xsdp())
+    {
+      auto data = xsdp->pointer().data();
+
+      system_description_pointer = reinterpret_cast<kapi::acpi::root_system_description_pointer const *>(data);
+    }
+    else if (auto const & rsdp = mbi->maybe_acpi_rsdp())
+    {
+      auto data = rsdp->pointer().data();
+      system_description_pointer = reinterpret_cast<kapi::acpi::root_system_description_pointer const *>(data);
+    }
+
+    return kstd::make_observer(system_description_pointer);
+  }
+
+}  // namespace kapi::acpi
\ No newline at end of file
diff --git a/arch/x86_64/kapi/devices.cpp b/arch/x86_64/kapi/devices.cpp
index b15503d..47c7f8c 100644
--- a/arch/x86_64/kapi/devices.cpp
+++ b/arch/x86_64/kapi/devices.cpp
@@ -1,35 +1,14 @@
 #include "kapi/devices.hpp"
 
-#include "arch/bus/isa.hpp"
-#include "arch/devices/legacy_pit.hpp"
-
-#include <kstd/memory>
-#include <kstd/print>
-
-#include <cstdint>
-#include <utility>
+#include "arch/devices/init.hpp"
 
 namespace kapi::devices
 {
 
-  namespace
-  {
-    constexpr auto pit_frequency_in_hz = std::uint32_t{100u};
-  }
-
   auto init_platform_devices() -> void
   {
-    kstd::println("[x86_64:devices] Initializing ISA bus...");
-
-    auto isa_major_number = kapi::devices::allocate_major_number();
-    auto isa_bus = kstd::make_unique<arch::bus::isa>(isa_major_number);
-
-    auto pit_major_number = kapi::devices::allocate_major_number();
-    auto pit = kstd::make_unique<arch::devices::legacy_pit>(pit_major_number, pit_frequency_in_hz);
-    isa_bus->add_child(std::move(pit));
-
-    auto & root_bus = get_root_bus();
-    root_bus.add_child(std::move(isa_bus));
+    arch::devices::init_acpi_devices();
+    arch::devices::init_legacy_devices();
   }
 
 }  // namespace kapi::devices
\ No newline at end of file
diff --git a/arch/x86_64/kapi/platform.cpp b/arch/x86_64/kapi/platform.cpp
new file mode 100644
index 0000000..380fc66
--- /dev/null
+++ b/arch/x86_64/kapi/platform.cpp
@@ -0,0 +1,71 @@
+#include "kapi/platform.hpp"
+
+#include "kapi/acpi.hpp"
+#include "kapi/devices.hpp"
+#include "kapi/memory.hpp"
+
+#include "arch/devices/local_apic.hpp"
+
+#include <kstd/memory>
+#include <kstd/print>
+
+#include <cstddef>
+#include <utility>
+
+namespace kapi::platform
+{
+
+  namespace
+  {
+    constexpr auto default_lapic_address = kapi::memory::physical_address{0xFEE0'0000};
+  }
+
+  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 static core_index = 0uz;
+
+    auto madt = kapi::acpi::get_table("APIC");
+    if (!madt)
+    {
+      kstd::println("[x86_64:PLT] Failed to find ACPI APIC table");
+      return false;
+    }
+
+    auto const * current = reinterpret_cast<std::byte const *>(madt.get()) + sizeof(kapi::acpi::madt_header);
+    auto const * end = reinterpret_cast<std::byte const *>(madt.get()) + madt->length();
+
+    auto bsp_found = false;
+    auto core_count = 0uz;
+
+    while (current < end)
+    {
+      auto const * sub_table = reinterpret_cast<kapi::acpi::madt_subtable_header const *>(current);
+      if (sub_table->type() == 0)
+      {
+        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_index,
+                                                                    local_apic->apic_id(), default_lapic_address);
+          if (kapi::platform::cpu_detected(bus, core_major, core_index, local_apic->processor_id(), is_bsp,
+                                           std::move(lapic)))
+          {
+            ++core_count;
+          }
+        }
+      }
+
+      current += sub_table->length();
+    }
+
+    kstd::println("[x86_64:PLT] Found {} CPU cores", core_count);
+
+    return core_count > 0;
+  }
+
+}  // namespace kapi::platform
\ No newline at end of file