Initial commit

kernel/cpu/idt.h

@@ -0,0 +1,35 @@
+//
+// Created by rick on 8/18/19.
+//
+#include "../types.h"
+
+#ifndef MY_KERNEL_IDT_H
+#define MY_KERNEL_IDT_H
+#define KERNEL_CS 0x08
+
+/* How every interrupt gate (handler) is defined */
+typedef struct {
+    u16 low_offset; /* Lower 16 bits of handler function address */
+    u16 sel; /* Kernel segment selector */
+    u8 always0;
+    /* First byte
+     * Bit 7: "Interrupt is present"
+     * Bits 6-5: Privilege level of caller (0=kernel..3=user)
+     * Bit 4: Set to 0 for interrupt gates
+     * Bits 3-0: bits 1110 = decimal 14 = "32 bit interrupt gate" */
+    u8 flags;
+    u16 high_offset; /* Higher 16 bits of handler function address */
+} __attribute__((packed)) idt_gate_t;
+
+typedef struct {
+    u16 limit;
+    u32 base;
+} __attribute__((packed)) idt_register_t;
+
+#define IDT_REGISTERS 256
+
+void set_idt_gate(int n, u32 handler);
+
+void set_idt();
+
+#endif //MY_KERNEL_IDT_H