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#include "syscall.h"
#include <kernel/isr.h>
#include <kernel/io.h>
#include <kernel/pic.h>
#include <kernel/string.h>
#include <stdint.h>
#define SEGMENT_PRESENT 0x80
#define SEGMENT_RING0 0x00
#define SEGMENT_RING3 0x60
#define SEGMENT_STORAGE 0x00
#define SEGMENT_INTERRUPT 0x0E
#define IDT_EXCEPTION (SEGMENT_PRESENT | SEGMENT_INTERRUPT)
#define IDT_INTERRUPT (SEGMENT_PRESENT | SEGMENT_INTERRUPT)
#define IDT_MAX_DESCRIPTORS 256
struct idt_entry {
uint16_t isr_low;
uint16_t kernel_cs;
uint8_t reserved;
uint8_t flags;
uint16_t isr_high;
} __attribute__((packed));
struct idt_ptr {
uint16_t limit;
uint32_t base;
} __attribute__((packed));
__attribute__((aligned(0x10)))
struct idt_entry idt[256];
struct idt_ptr idtr;
char *exceptions[] = {
"Division by zero",
"Debug",
"Non-maskable interrupt",
"Breakpoint",
"Overflow",
"Out-of-bounds",
"Invalid opcode",
"FPU not available",
"Double fault",
"RESERVED",
"Invalid TSS",
"Segment not present",
"Stack fault",
"General protection fault",
"Page fault",
"RESERVED",
"FPU exception",
"Alignment check",
"Machine check",
"FPU-SIMD exception",
"Virtualization exception",
"Control protection"
"RESERVED",
"Hypervisor injection",
"VMM exception",
"Security exception",
"RESERVED",
"Triple fault",
"RESERVED"
};
__attribute__((noreturn))
void halt_catch_fire(struct isr_frame *frame) {
kprintf("Registers at interrupt:\n");
kprintf("\tEAX = %x\n", frame->eax);
kprintf("\tEBX = %x\n", frame->ebx);
kprintf("\tECX = %x\n", frame->ecx);
kprintf("\tEDX = %x\n", frame->edx);
kprintf("\tESI = %x\n", frame->esi);
kprintf("\tEDI = %x\n", frame->edi);
kprintf("\tESP = %x\n", frame->esp);
kprintf("\tEBP = %x\n", frame->ebp);
kprintf("\tEIP = %x\n", frame->eip);
kprintf("\tEFLAGS = %x\n", frame->eflags);
kprintf("Current code selector: %d\n", frame->cs);
__asm__ volatile("cli;hlt");
}
__attribute__((noreturn))
void exception_handler(struct isr_frame *frame) {
switch (frame->vector) {
default:
kprintf("Unhandled exception: %s\n", exceptions[frame->vector]);
halt_catch_fire(frame);
}
}
void irq_dispatch(uint8_t irq, struct isr_frame *frame) {
return;
}
__attribute__((noreturn))
void interrupt_handler(struct isr_frame *frame) {
if (frame->vector < 32)
exception_handler(frame);
else if (frame->vector > 32 && frame->vector < 48)
irq_dispatch(frame->vector - 16, frame);
switch (frame->vector) {
case 0x80:
syscall_dispatch(frame);
break;
default:
kprintf("Error: Unmapped interrupt: %d\n", frame->vector);
halt_catch_fire(frame);
__asm__ volatile("cli;hlt");
}
}
void idt_set_gate(uint8_t num, void (*handler)(void), uint16_t cs, uint8_t flags) {
struct idt_entry *desc = &idt[num];
desc->isr_low = (uint16_t)(((uint32_t)handler >> 0) & 0xFFFF);
desc->isr_high = (uint16_t)(((uint32_t)handler >> 16) & 0xFFFF);
desc->reserved = 0;
desc->kernel_cs = cs;
desc->flags = flags;
}
void idt_install(void) {
idtr.limit = (uint16_t)sizeof(struct idt_entry) * 256 - 1;
idtr.base = (uint32_t)idt;
idt_set_gate(0, isr_stub_0, 0x08, IDT_EXCEPTION);
idt_set_gate(1, isr_stub_1, 0x08, IDT_EXCEPTION);
idt_set_gate(2, isr_stub_2, 0x08, IDT_EXCEPTION);
idt_set_gate(3, isr_stub_3, 0x08, IDT_EXCEPTION);
idt_set_gate(4, isr_stub_4, 0x08, IDT_EXCEPTION);
idt_set_gate(5, isr_stub_5, 0x08, IDT_EXCEPTION);
idt_set_gate(6, isr_stub_6, 0x08, IDT_EXCEPTION);
idt_set_gate(7, isr_stub_7, 0x08, IDT_EXCEPTION);
idt_set_gate(8, isr_stub_8, 0x08, IDT_EXCEPTION);
idt_set_gate(9, isr_stub_9, 0x08, IDT_EXCEPTION);
idt_set_gate(10, isr_stub_10, 0x08, IDT_EXCEPTION);
idt_set_gate(11, isr_stub_11, 0x08, IDT_EXCEPTION);
idt_set_gate(12, isr_stub_12, 0x08, IDT_EXCEPTION);
idt_set_gate(13, isr_stub_13, 0x08, IDT_EXCEPTION);
idt_set_gate(14, isr_stub_14, 0x08, IDT_EXCEPTION);
idt_set_gate(15, isr_stub_15, 0x08, IDT_EXCEPTION);
idt_set_gate(16, isr_stub_16, 0x08, IDT_EXCEPTION);
idt_set_gate(17, isr_stub_17, 0x08, IDT_EXCEPTION);
idt_set_gate(18, isr_stub_18, 0x08, IDT_EXCEPTION);
idt_set_gate(19, isr_stub_19, 0x08, IDT_EXCEPTION);
idt_set_gate(20, isr_stub_20, 0x08, IDT_EXCEPTION);
idt_set_gate(21, isr_stub_21, 0x08, IDT_EXCEPTION);
idt_set_gate(22, isr_stub_22, 0x08, IDT_EXCEPTION);
idt_set_gate(23, isr_stub_23, 0x08, IDT_EXCEPTION);
idt_set_gate(24, isr_stub_24, 0x08, IDT_EXCEPTION);
idt_set_gate(25, isr_stub_25, 0x08, IDT_EXCEPTION);
idt_set_gate(26, isr_stub_26, 0x08, IDT_EXCEPTION);
idt_set_gate(27, isr_stub_27, 0x08, IDT_EXCEPTION);
idt_set_gate(28, isr_stub_28, 0x08, IDT_EXCEPTION);
idt_set_gate(29, isr_stub_29, 0x08, IDT_EXCEPTION);
idt_set_gate(30, isr_stub_30, 0x08, IDT_EXCEPTION);
idt_set_gate(31, isr_stub_31, 0x08, IDT_EXCEPTION);
idt_set_gate(128, syscall_stub, 0x08, IDT_INTERRUPT);
register_syscall(halt_catch_fire, 0);
__asm__ volatile("lidt %0" : : "memory"(idtr));
__asm__ volatile("sti");
}
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