kernel/src/arch/CPU.h

@@ -29,5 +29,7 @@ namespace CPU
 
     u16 get_processor_id();
 
+    bool register_interrupt(u8 interrupt, void (*handler)(Registers*));
+
     void pause();
 }

kernel/src/arch/x86_64/CPU.asm

@@ -188,4 +188,18 @@ ISR_ERROR 21 ; control-protection exception (#CP)
 ; ISR 22-31 reserved
 IRQ 32, 0 ; timer interrupt
 IRQ 33, 1 ; keyboard interrupt
+IRQ 34, 2
+IRQ 35, 3
+IRQ 36, 4
+IRQ 37, 5
+IRQ 38, 6
+IRQ 39, 7
+IRQ 40, 8
+IRQ 41, 9
+IRQ 42, 10
+IRQ 43, 11
+IRQ 44, 12
+IRQ 45, 13
+IRQ 46, 14
+IRQ 47, 15
 ISR 66 ; system call

kernel/src/arch/x86_64/CPU.cpp

@@ -28,6 +28,10 @@ extern void setup_idt();
 
 static Thread* g_io_thread;
 
+typedef void (*interrupt_handler_t)(Registers*);
+
+static interrupt_handler_t irq_handlers[16];
+
 void FPData::save()
 {
     asm volatile("fxsave (%0)" : : "r"(m_data));
@@ -150,21 +154,34 @@ void io_thread()
     }
 }
 
+static void timer_interrupt(Registers* regs)
+{
+    Timer::tick();
+    if (should_invoke_scheduler()) Scheduler::invoke(regs);
+}
+
+static void keyboard_interrupt(Registers*)
+{
+    u8 scancode = IO::inb(0x60);
+    scancode_queue.try_push(scancode);
+    g_io_thread->wake_up();
+}
+
 // 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) // Timer interrupt
+    else if (regs->isr >= 32 && regs->isr < 48) // IRQ from the PIC
     {
-        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);
-        g_io_thread->wake_up();
+        u64 irq = regs->error;
+        interrupt_handler_t handler = irq_handlers[irq];
+        if (!handler)
+        {
+            kwarnln("Unhandled IRQ catched! Halting.");
+            CPU::efficient_halt();
+        }
+
+        handler(regs);
         pic_eoi(regs);
     }
     else if (regs->isr == 66) // System call
@@ -174,7 +191,7 @@ extern "C" void arch_interrupt_entry(Registers* regs)
     }
     else
     {
-        kwarnln("IRQ catched! Halting.");
+        kwarnln("Unhandled interrupt catched! Halting.");
         CPU::efficient_halt();
     }
 }
@@ -233,6 +250,10 @@ namespace CPU
             kwarnln("not setting the NX bit as it is unsupported");
         setup_gdt();
         setup_idt();
+
+        memset(irq_handlers, 0, sizeof(irq_handlers));
+        register_interrupt(0, timer_interrupt);
+        register_interrupt(1, keyboard_interrupt);
     }
 
     void platform_finish_init()
@@ -353,6 +374,15 @@ namespace CPU
         __get_cpuid(1, &unused, &ebx, &unused, &unused);
         return (u16)(ebx >> 24);
     }
+
+    bool register_interrupt(u8 interrupt, interrupt_handler_t handler)
+    {
+        if (irq_handlers[interrupt]) return false;
+
+        irq_handlers[interrupt] = handler;
+
+        return true;
+    }
 }
 
 // called by kernel_yield