x86_64: Add basic keyboard support with an ASYNC DRIVER

kernel/src/arch/x86_64/CPU.asm

@@ -187,3 +187,4 @@ ISR 20 ; virtualization exception (#VE)
 ISR_ERROR 21 ; control-protection exception (#CP)
 ; ISR 22-31 reserved
 IRQ 32, 0 ; timer interrupt
+IRQ 33, 0 ; keyboard interrupt

kernel/src/arch/x86_64/CPU.cpp

@@ -2,10 +2,12 @@
 #include "Log.h"
 #include "arch/Timer.h"
 #include "arch/x86_64/CPU.h"
+#include "arch/x86_64/IO.h"
 #include "memory/MemoryManager.h"
 #include "thread/Scheduler.h"
 #include <cpuid.h>
 #include <luna/CString.h>
+#include <luna/CircularQueue.h>
 #include <luna/Result.h>
 #include <luna/SystemError.h>
 #include <luna/Types.h>
@@ -76,16 +78,35 @@ extern "C" void handle_x86_exception(Registers* regs)
     }
 }
 
+CircularQueue<u8, 60> scancode_queue;
+
+void io_thread()
+{
+    while (true)
+    {
+        u8 scancode;
+        while (!scancode_queue.try_pop(scancode)) { kernel_sleep(10); }
+
+        kinfoln("Read scancode: %#hhx", scancode);
+    }
+}
+
 // Called from _asm_interrupt_entry
 extern "C" void arch_interrupt_entry(Registers* regs)
 {
     if (regs->isr < 32) handle_x86_exception(regs);
-    else if (regs->isr == 32)
+    else if (regs->isr == 32) // Timer interrupt
     {
         Timer::tick();
         if (should_invoke_scheduler()) Scheduler::invoke(regs);
         pic_eoi(regs);
     }
+    else if (regs->isr == 33) // Keyboard interrupt
+    {
+        u8 scancode = IO::inb(0x60);
+        scancode_queue.try_push(scancode);
+        pic_eoi(regs);
+    }
     else
     {
         kwarnln("IRQ catched! Halting.");
@@ -151,6 +172,8 @@ namespace CPU
 
     void platform_finish_init()
     {
+        Scheduler::new_kernel_thread(io_thread).expect_value("Could not create the IO background thread!");
+
         remap_pic();
     }
 

kernel/src/arch/x86_64/init/IDT.cpp

@@ -82,6 +82,7 @@ INT(19);
 INT(20);
 INT(21);
 INT(32);
+INT(33);
 
 void setup_idt()
 {
@@ -108,6 +109,7 @@ void setup_idt()
     TRAP(20);
     TRAP(21);
     IRQ(32);
+    IRQ(33);
 
     static IDTR idtr;
     idtr.limit = 0x0FFF;

kernel/src/arch/x86_64/init/PIC.cpp

@@ -36,7 +36,7 @@ void remap_pic()
     IO::outb(PIC2_DATA, ICW4_8086);
     io_delay();
 
-    IO::outb(PIC1_DATA, 0b11111110);
+    IO::outb(PIC1_DATA, 0b11111100);
     io_delay();
     IO::outb(PIC2_DATA, 0b11111111);
 }

kernel/src/main.cpp

@@ -12,25 +12,12 @@
 #include "memory/MemoryManager.h"
 #include "thread/Scheduler.h"
 #include <luna/CString.h>
+#include <luna/CircularQueue.h>
 #include <luna/Result.h>
 #include <luna/Units.h>
 
 extern const BOOTBOOT bootboot;
 
-void async_thread()
-{
-    while (true)
-    {
-        Thread* current = Scheduler::current();
-        kinfoln("Ticks: %lu, %lu user, %lu kernel, %lu idle", current->ticks, current->ticks_in_user,
-                current->ticks_in_kernel, Scheduler::idle()->ticks);
-
-        CPU::wait_for_interrupt();
-
-        kernel_sleep(1000);
-    }
-}
-
 void heap_thread()
 {
     CPU::disable_interrupts();
@@ -90,7 +77,6 @@ Result<void> init()
     Thread::init();
     Scheduler::init();
 
-    TRY(Scheduler::new_kernel_thread(async_thread));
     TRY(Scheduler::new_kernel_thread(heap_thread));
     TRY(Scheduler::new_kernel_thread(reap_thread));
 

luna/include/luna/CircularQueue.h

@@ -0,0 +1,57 @@
+#pragma once
+#include <luna/Atomic.h>
+#include <luna/Types.h>
+
+template <typename T, usize Size> class CircularQueue
+{
+    enum
+    {
+        Capacity = Size + 1
+    };
+
+  public:
+    CircularQueue()
+    {
+    }
+
+    bool try_push(const T& value)
+    {
+        usize current_tail = m_tail.load(MemoryOrder::Relaxed);
+        const usize new_tail = (current_tail + 1) % Capacity;
+        if (new_tail == m_head.load(MemoryOrder::Acquire))
+        {
+            // Queue is full
+            return false;
+        }
+        m_data[current_tail] = value;
+        if (!m_tail.compare_exchange_strong(current_tail, new_tail, MemoryOrder::Release, MemoryOrder::Relaxed))
+        {
+            // Someone else updated the tail
+            return false;
+        }
+        return true;
+    }
+
+    bool try_pop(T& value)
+    {
+        usize current_head = m_head.load(MemoryOrder::Relaxed);
+        if (current_head == m_tail.load(MemoryOrder::Acquire))
+        {
+            // Queue is empty
+            return false;
+        }
+        value = m_data[current_head];
+        const usize new_head = (current_head + 1) % Capacity;
+        if (!m_head.compare_exchange_strong(current_head, new_head, MemoryOrder::Release, MemoryOrder::Relaxed))
+        {
+            // Someone else updated the head
+            return false;
+        }
+        return true;
+    }
+
+  private:
+    T m_data[Capacity];
+    Atomic<usize> m_head = 0;
+    Atomic<usize> m_tail = 0;
+};