1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
#ifndef DEF_IDT_H
#define DEF_IDT_H
/* The IDT is the system descriptor table that tells the CPU what to do when an interrupt fires.
There are three categories of interrupts :
- Exceptions ; ex: page fault, divide by 0
- IRQ : interrupts caused by hardware
- System calls : when an applications asks the system to do something */
#include <types.h>
struct idt_entry {
uint16_t base_lo; //Low part of address to jump to
uint16_t sel; //Kernel segment selector
uint8_t always0;
uint8_t flags; //Flags
uint16_t base_hi; //High part of address to jump to
} __attribute__((packed));
struct idt_ptr {
uint16_t limit;
uint32_t base;
} __attribute__((packed));
struct registers {
uint32_t ds; // Data segment selector
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, cs, eflags, useresp, ss; // Pushed by the processor automatically.
};
typedef void (*int_callback)(registers*);
void idt_init();
void idt_handleIrq(int number, int_callback func); //Set IRQ handler
void idt_waitIrq(int number); //ask current thread to wait for IRQ
#endif
|
