hazel/include/kernel/idt.h

#ifndef HAZEL_IDT_H_
#define HAZEL_IDT_H_

#include <stdint.h>

#define GDT_SEGMENT_SELECTOR(i, p) ((i << 3) | p)
#define LDT_SEGMENT_SELECTOR(i, p) ((i << 3) | 0x04 | p)

#define IDT_ENTRY_COUNT 256

struct idt_entry {
   uint16_t offset_lo; 
   uint16_t seg_select;
   uint8_t  reserved;
   uint8_t  attributes;
   uint16_t offset_hi;
} __attribute__ ((packed));

struct idtr {
    uint16_t size;
    uint32_t base;
} __attribute__ ((packed));

enum IDT_ATTRIBUTES {
    TASK_GATE    = 0x05,
    INT_GATE_16  = 0x06,
    TRAP_GATE_16 = 0x07,
    INT_GATE_32  = 0x0E,
    TRAP_GATE_32 = 0x0F,

    INT_RING0 = 0x00,
    INT_RING1 = 0x20,
    INT_RING2 = 0x40,
    INT_RING3 = 0x60,

    INT_PRESENT = 0x80,
};

typedef struct {
    uint32_t edi, esi, ebp, esp, ebx, edx, ecx, eax; /*  Pushed by pusha. */
    uint32_t int_no, err_code;    /*  Interrupt number and error code (if applicable) */

    uint32_t eip;
    uint32_t cs;
    uint32_t eflags;
} int_stack_frame_t;

typedef struct {
    uint32_t edi, esi, ebp, esp, ebx, edx, ecx, eax; /*  Pushed by pusha. */
} stack_frame_t;

void idt_encode_entry(struct idt_entry idt[], int i, uint32_t offset, uint16_t segment_selector, uint8_t attributes);

#endif