1 files changed, 84 insertions, 0 deletions
diff --git a/kernel/irq.c b/kernel/irq.c
new file mode 100644
index 0000000..5f0a3f5
--- /dev/null
+++ b/kernel/irq.c
@@ -0,0 +1,84 @@
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+#include "idt.h"
+#include "io.h"
+#include "irq.h"
+#include "isr.h"
+
+static void *irq_callbacks[16] = { NULL };
+
+void irq_set_handler(int irq, void (*handler)(struct regs_t*))
+{
+    if(irq < 16 && irq >= 0)
+        irq_callbacks[irq] = handler;
+}
+
+void irq_reset_handler(int irq)
+{
+    if(irq < 16 && irq >= 0)
+        irq_callbacks[irq] = NULL;
+}
+
+void irq_remap(void)
+{
+    outb(0x20, 0x11);
+    outb(0xA0, 0x11);
+    outb(0x21, 0x20);
+    outb(0xA1, 0x28);
+    outb(0x21, 0x04);
+    outb(0xA1, 0x02);
+    outb(0x21, 0x01);
+    outb(0xA1, 0x01);
+    outb(0x21, 0x0);
+    outb(0xA1, 0x0);
+}
+
+void irq_init(void)
+{
+    irq_remap();
+
+    printf("irq_init()");
+
+    idt_set_gate(32, (uint32_t)_irq0, 0x08, 0x8E);
+    idt_set_gate(33, (uint32_t)_irq1, 0x08, 0x8E);
+    idt_set_gate(34, (uint32_t)_irq2, 0x08, 0x8E);
+    idt_set_gate(35, (uint32_t)_irq3, 0x08, 0x8E);
+    idt_set_gate(36, (uint32_t)_irq4, 0x08, 0x8E);
+    idt_set_gate(37, (uint32_t)_irq5, 0x08, 0x8E);
+    idt_set_gate(38, (uint32_t)_irq6, 0x08, 0x8E);
+    idt_set_gate(39, (uint32_t)_irq7, 0x08, 0x8E);
+    idt_set_gate(40, (uint32_t)_irq8, 0x08, 0x8E);
+    idt_set_gate(41, (uint32_t)_irq9, 0x08, 0x8E);
+    idt_set_gate(42, (uint32_t)_irq10, 0x08, 0x8E);
+    idt_set_gate(43, (uint32_t)_irq11, 0x08, 0x8E);
+    idt_set_gate(44, (uint32_t)_irq12, 0x08, 0x8E);
+    idt_set_gate(45, (uint32_t)_irq13, 0x08, 0x8E);
+    idt_set_gate(46, (uint32_t)_irq14, 0x08, 0x8E);
+    idt_set_gate(47, (uint32_t)_irq15, 0x08, 0x8E);
+}
+
+void irq_handler(struct regs_t *regs)
+{
+    void (*handler)(struct regs_t *r);
+
+    handler = irq_callbacks[regs->int_no - 32];
+
+    printf("IRQ called\n");
+
+    if(handler)
+    {
+        handler(regs);
+    }
+
+    /* If the IDT entry that was invoked was greater than 40
+     *  (meaning IRQ8 - 15), then we need to send an EOI to
+     *  the slave controller */
+    if (regs->int_no >= 40)
+    {
+        outb(0xA0, 0x20);
+    }
+
+    /* send an EOI to the master controller */
+    outb(0x20, 0x20);
+}