x86_64: implement LAPIC initialization

1 files changed, 31 insertions, 2 deletions

diff --git a/arch/x86_64/src/devices/local_apic.cpp b/arch/x86_64/src/devices/local_apic.cpp
index beb75ef..91e907a 100644
--- a/arch/x86_64/src/devices/local_apic.cpp
+++ b/arch/x86_64/src/devices/local_apic.cpp
@@ -11,6 +11,14 @@
 namespace arch::devices
 {
 
+  namespace
+  {
+    constexpr auto lapic_sivr_register = 0x00F0uz;
+
+    constexpr auto lapic_enable_bit = 0x100u;
+    constexpr auto spurious_interrupt_vector = 0xFFu;
+  }  // namespace
+
   local_apic::local_apic(std::size_t major, std::size_t minor, std::uint64_t hardware_id,
                          kapi::memory::physical_address base)
       : kapi::devices::device{major, minor, "lapic"}
@@ -20,9 +28,30 @@ namespace arch::devices
 
   auto local_apic::init() -> bool
   {
-    kstd::println("[x86_64:DEV] Initializing local APIC on core {}", m_hardware_id);
+    m_virtual_base = kapi::memory::allocate_mmio_region(1);
+    if (!kapi::memory::map_mmio_region(m_virtual_base, m_base, kapi::memory::page_mapper::flags::writable))
+    {
+      kstd::println("[x86_64:DEV] LAPIC {} MMIO mapping failed!", m_hardware_id);
+      return false;
+    }
+
+    write_register(lapic_sivr_register, lapic_enable_bit | spurious_interrupt_vector);
+
+    kstd::println("[x86_64:DEV] LAPIC {} initialized. {:#018x}@{:#018x}", m_hardware_id, m_base, m_virtual_base);
 
     return true;
   }
 
-}  // namespace arch::devices
\ No newline at end of file
+  auto local_apic::read_register(std::size_t offset) const -> std::uint32_t
+  {
+    auto reg = static_cast<std::uint32_t volatile *>(m_virtual_base + offset);
+    return *reg;
+  }
+
+  auto local_apic::write_register(std::size_t offset, std::uint32_t value) -> void
+  {
+    auto reg = static_cast<std::uint32_t volatile *>(m_virtual_base + offset);
+    *reg = value;
+  }
+
+}  // namespace arch::devices