summaryrefslogtreecommitdiff
path: root/src/kernel/task/idt.cpp
blob: c09034e6b8cc0655d6fcd7f2c40a04d88b2e6fb8 (plain) (blame)
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
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
#include "idt.h"
#include <core/monitor.h>
#include <core/sys.h>
#include <mem/paging.h>
#include <lib/cpp.h>
#include "task.h"
#include "syscall.h"

#include <stdlib_common.h>

extern "C" {

extern void isr0();
extern void isr1();
extern void isr2();
extern void isr3();
extern void isr4();
extern void isr5();
extern void isr6();
extern void isr7();
extern void isr8();
extern void isr9();
extern void isr10();
extern void isr11();
extern void isr12();
extern void isr13();
extern void isr14();
extern void isr15();
extern void isr16();
extern void isr17();
extern void isr18();
extern void isr19();
extern void isr20();
extern void isr21();
extern void isr22();
extern void isr23();
extern void isr24();
extern void isr25();
extern void isr26();
extern void isr27();
extern void isr28();
extern void isr29();
extern void isr30();
extern void isr31();

extern void irq0();
extern void irq1();
extern void irq2();
extern void irq3();
extern void irq4();
extern void irq5();
extern void irq6();
extern void irq7();
extern void irq8();
extern void irq9();
extern void irq10();
extern void irq11();
extern void irq12();
extern void irq13();
extern void irq14();
extern void irq15();

extern void syscall64();

}

extern "C" void idt_flush(int32_t ptr);

idt_entry idt_entries[256];
idt_ptr idt_ptr;

static int_callback irq_handlers[16] = {0};
static struct irq_waiter {
	struct thread *thread;
	irq_waiter *next;
} *irq_wakeup[16] = {0};

/*	Called in idt_.asm when an exception fires (interrupt 0 to 31).
	Tries to handle the exception, panics if fails. */
extern "C" void idt_isrHandler(registers regs) {
	if ((regs.int_no == 14 && paging_fault(&regs) != 0) || regs.int_no != 14) {
		if (tasking_handleException(&regs) == 0) {
			monitor_write("\nREALLY BAD THIS TIME\t\tUnhandled exception\t#");
			monitor_writeDec(regs.int_no);
			monitor_write("\t@"); monitor_writeHex(regs.eip);
			PANIC("Unhandled Exception");
		}
	}
} 

/*	Called in idt_.asm when an IRQ fires (interrupt 32 to 47)
	Possibly wakes up a thread that was waiting, possibly calls a handler. */
extern "C" void idt_irqHandler(registers regs) {
	uint32_t doSwitch = (regs.err_code == 0);	//IRQ0 = timer
	if (regs.err_code > 7) {
		outb(0xA0, 0x20);
	}
	outb(0x20, 0x20);
	while (irq_wakeup[regs.err_code] != 0) {
		irq_waiter *tmp = irq_wakeup[regs.err_code];
		tmp->thread->wakeUp();
		irq_wakeup[regs.err_code] = tmp->next;
		kfree(tmp);
		doSwitch = 1;
	}
	if (irq_handlers[regs.err_code] != 0) {
		irq_handlers[regs.err_code](&regs);
	}
	if (doSwitch) schedule();
}

/*	For internal use only. Sets up an entry of the IDT with given parameters. */
static void idt_setGate(uint8_t num, uint32_t base, uint16_t sel, uint8_t flags) {
	idt_entries[num].base_lo = base & 0xFFFF;
	idt_entries[num].base_hi = (base >> 16) & 0xFFFF;

	idt_entries[num].sel = sel;
	idt_entries[num].always0 = 0;
	idt_entries[num].flags = flags | 0x60;
}

/*	Remaps the IRQs. Sets up the IDT. */
void idt_init() {
	idt_ptr.limit = (sizeof(idt_entry) * 256) - 1;
	idt_ptr.base = (uint32_t)&idt_entries;

	memset((uint8_t*)&idt_entries, 0, sizeof(idt_entry) * 256);

	//Remap the IRQ table
	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);

	idt_setGate(0, (int32_t)isr0, 0x08, 0x8E);
	idt_setGate(1, (int32_t)isr1, 0x08, 0x8E);
	idt_setGate(2, (int32_t)isr2, 0x08, 0x8E);
	idt_setGate(3, (int32_t)isr3, 0x08, 0x8E);
	idt_setGate(4, (int32_t)isr4, 0x08, 0x8E);
	idt_setGate(5, (int32_t)isr5, 0x08, 0x8E);
	idt_setGate(6, (int32_t)isr6, 0x08, 0x8E);
	idt_setGate(7, (int32_t)isr7, 0x08, 0x8E);
	idt_setGate(8, (int32_t)isr8, 0x08, 0x8E);
	idt_setGate(9, (int32_t)isr9, 0x08, 0x8E);
	idt_setGate(10, (int32_t)isr10, 0x08, 0x8E);
	idt_setGate(11, (int32_t)isr11, 0x08, 0x8E);
	idt_setGate(12, (int32_t)isr12, 0x08, 0x8E);
	idt_setGate(13, (int32_t)isr13, 0x08, 0x8E);
	idt_setGate(14, (int32_t)isr14, 0x08, 0x8E);
	idt_setGate(15, (int32_t)isr15, 0x08, 0x8E);
	idt_setGate(16, (int32_t)isr16, 0x08, 0x8E);
	idt_setGate(17, (int32_t)isr17, 0x08, 0x8E);
	idt_setGate(18, (int32_t)isr18, 0x08, 0x8E);
	idt_setGate(19, (int32_t)isr19, 0x08, 0x8E);
	idt_setGate(20, (int32_t)isr20, 0x08, 0x8E);
	idt_setGate(21, (int32_t)isr21, 0x08, 0x8E);
	idt_setGate(22, (int32_t)isr22, 0x08, 0x8E);
	idt_setGate(23, (int32_t)isr23, 0x08, 0x8E);
	idt_setGate(24, (int32_t)isr24, 0x08, 0x8E);
	idt_setGate(25, (int32_t)isr25, 0x08, 0x8E);
	idt_setGate(26, (int32_t)isr26, 0x08, 0x8E);
	idt_setGate(27, (int32_t)isr27, 0x08, 0x8E);
	idt_setGate(28, (int32_t)isr28, 0x08, 0x8E);
	idt_setGate(29, (int32_t)isr29, 0x08, 0x8E);
	idt_setGate(30, (int32_t)isr30, 0x08, 0x8E);
	idt_setGate(31, (int32_t)isr31, 0x08, 0x8E);

	idt_setGate(32, (int32_t)irq0, 0x08, 0x8E);
	idt_setGate(33, (int32_t)irq1, 0x08, 0x8E);
	idt_setGate(34, (int32_t)irq2, 0x08, 0x8E);
	idt_setGate(35, (int32_t)irq3, 0x08, 0x8E);
	idt_setGate(36, (int32_t)irq4, 0x08, 0x8E);
	idt_setGate(37, (int32_t)irq5, 0x08, 0x8E);
	idt_setGate(38, (int32_t)irq6, 0x08, 0x8E);
	idt_setGate(39, (int32_t)irq7, 0x08, 0x8E);
	idt_setGate(40, (int32_t)irq8, 0x08, 0x8E);
	idt_setGate(41, (int32_t)irq9, 0x08, 0x8E);
	idt_setGate(42, (int32_t)irq10, 0x08, 0x8E);
	idt_setGate(43, (int32_t)irq11, 0x08, 0x8E);
	idt_setGate(44, (int32_t)irq12, 0x08, 0x8E);
	idt_setGate(45, (int32_t)irq13, 0x08, 0x8E);
	idt_setGate(46, (int32_t)irq14, 0x08, 0x8E);
	idt_setGate(47, (int32_t)irq15, 0x08, 0x8E);

	idt_setGate(64, (int32_t)syscall64, 0x08, 0x8E);

	idt_flush((int32_t)&idt_ptr);

	monitor_write("[IDT] ");
}

/*	Sets up an IRQ handler for given IRQ. */
void idt_handleIrq(int number, int_callback func) {
	if (number < 16 && number >= 0) {
		irq_handlers[number] = func;
	}
}

/*	Tells the IRQ handler to wake up the current thread when specified IRQ fires. */
void idt_waitIrq(int number) {
	if (number < 16 && number >= 0 && proc_priv() <= PL_KERNEL) {
		irq_waiter *tmp = new irq_waiter();
		tmp->thread = current_thread;
		tmp->next = irq_wakeup[number];
		irq_wakeup[number] = tmp;

		thread_goInactive();
	}
}