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
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
#include <kernel/pic.h>
static void (*irq_handlers[16])(struct isr_frame *frame);
void pic_eoi(uint8_t irq) {
if (irq >= 8)
outb(PIC2_COMMAND, 0x20);
outb(PIC1_COMMAND, 0x20);
}
void pic_remap(void) {
unsigned char a1 = inb(PIC1_DATA);
unsigned char a2 = inb(PIC2_DATA);
outb(PIC1_COMMAND, ICW1_INIT | ICW1_ICW4);
outb(PIC2_COMMAND, ICW1_INIT | ICW1_ICW4);
outb(PIC1_DATA, PIC1);
outb(PIC2_DATA, PIC2);
outb(PIC1_DATA, 4);
outb(PIC2_DATA, 2);
outb(PIC1_DATA, ICW4_8086);
outb(PIC2_DATA, ICW4_8086);
outb(PIC1_DATA, a1);
outb(PIC2_DATA, a2);
}
static uint16_t _pic_get_irq_reg(int ocw3) {
outb(PIC1_COMMAND, ocw3);
outb(PIC2_COMMAND, ocw3);
return (inb(PIC2_COMMAND) << 8) | inb(PIC1_COMMAND);
}
uint16_t pic_get_irr(void) {
return _pic_get_irq_reg(PIC_READ_IRR);
}
uint16_t pic_get_isr(void) {
return _pic_get_irq_reg(PIC_READ_ISR);
}
void register_irq_handler(uint8_t irq, void (*handler)(struct isr_frame *frame)) {
irq_handlers[irq] = handler;
}
void irq_dispatch(struct isr_frame *frame) {
(*irq_handlers[frame->isr_vector-32])(frame);
pic_eoi(frame->isr_vector-32);
return;
}
void irq_set_mask(uint8_t irq) {
uint16_t port;
uint8_t data;
if (irq < 8) {
port = PIC1_DATA;
} else {
port = PIC2_DATA;
irq -= 8;
}
data = inb(port) | (1 << irq);
outb(port, data);
}
void irq_clear_mask(uint8_t irq) {
uint16_t port;
uint8_t data;
if (irq < 8) {
port = PIC1_DATA;
} else {
port = PIC2_DATA;
irq -= 8;
}
data = inb(port) & ~(1 << irq);
outb(port, data);
}
|
