1 files changed, 37 insertions, 0 deletions
diff --git a/arch/x86_64/src/cpu/initialization.cpp b/arch/x86_64/src/cpu/initialization.cpp
index 214687c..85da38d 100644
--- a/arch/x86_64/src/cpu/initialization.cpp
+++ b/arch/x86_64/src/cpu/initialization.cpp
@@ -4,6 +4,7 @@
 #include "arch/cpu/interrupts.hpp"
 #include "arch/cpu/segment_descriptor.hpp"
 #include "arch/cpu/task_state_segment.hpp"
+#include "arch/device_io/port_io.hpp"
 
 #include <kstd/print>
 
@@ -130,4 +131,40 @@ namespace arch::cpu
     idt.load();
   }
 
+  auto initialize_legacy_interrupts() -> void
+  {
+    using pic_master_control_port = io::port<0x20, std::uint8_t, io::port_read, io::port_write>;
+    using pic_master_data_port = io::port<0x21, std::uint8_t, io::port_read, io::port_write>;
+    using pic_slave_control_port = io::port<0xa0, std::uint8_t, io::port_read, io::port_write>;
+    using pic_slave_data_port = io::port<0xa1, std::uint8_t, io::port_read, io::port_write>;
+
+    constexpr auto pic_init_command = std::uint8_t{0x11};
+    constexpr auto pic_master_offset = std::uint8_t{0x20};
+    constexpr auto pic_slave_offset = std::uint8_t{0x28};
+    constexpr auto pic_cascade_address = std::uint8_t{0x04};
+    constexpr auto pic_cascade_slave_identity = std::uint8_t{0x02};
+    constexpr auto pic_use_8086_mode = std::uint8_t{0x01};
+    constexpr auto pic_master_mask = std::uint8_t{0xfb};
+    constexpr auto pic_slave_mask = std::uint8_t{0xff};
+    constexpr auto pic_timer_mask = std::uint8_t{0x01};
+
+    pic_master_control_port::write(pic_init_command);
+    pic_slave_control_port::write(pic_init_command);
+
+    pic_master_data_port::write(pic_master_offset);
+    pic_slave_data_port::write(pic_slave_offset);
+
+    pic_master_data_port::write(pic_cascade_address);
+    pic_slave_data_port::write(pic_cascade_slave_identity);
+
+    pic_master_data_port::write(pic_use_8086_mode);
+    pic_slave_data_port::write(pic_use_8086_mode);
+
+    pic_master_data_port::write(pic_master_mask);
+    pic_slave_data_port::write(pic_slave_mask);
+
+    auto const current_master_mask = pic_master_data_port::read();
+    pic_master_data_port::write<std::uint8_t>(current_master_mask | pic_timer_mask);
+  }
+
 }  // namespace arch::cpu