k-chow/k/idt.c

#include "idt.h"
#include "stdio.h"

static struct idt idt = { 0 };

static struct idt_entry_descriptor idt_entries_descriptors[] = {
    {(uint32_t)&isr_divide, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 0
    {(uint32_t)&isr_debug, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 1
    {(uint32_t)&isr_nmi, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 2
    {(uint32_t)&isr_breakpoint, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 3
    {(uint32_t)&isr_overflow, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 4
    {(uint32_t)&isr_bound_range_exceeded, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 5
    {(uint32_t)&isr_invalid_opcode, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 6
    {(uint32_t)&isr_device_not_available, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 7
    {(uint32_t)&isr_double_fault, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 8
    {(uint32_t)&isr_coprocessor_segment_overrun, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 9
    {(uint32_t)&isr_invalid_tss, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 10
    {(uint32_t)&isr_segment_not_present, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 11
    {(uint32_t)&isr_stack_segment_fault, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 12
    {(uint32_t)&isr_general_protection, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 13
    {(uint32_t)&isr_page_fault, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 14
    {0, {0, 0, 0}, 0}, // 15
    {(uint32_t)&isr_fpu_floating_point_error, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 16
    {(uint32_t)&isr_alignment_check, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 17
    {(uint32_t)&isr_machine_check, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 18
    {(uint32_t)&isr_simd_floating_point_exception, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 19
    {(uint32_t)&isr_virtualization_exception, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 20
    {(uint32_t)&isr_control_protection_exception, KERNEL_CS_SEGMENT_SELECTOR, INTERRUPT_TYPE}, // 21
    {0, {0, 0, 0}, 0}, // 22
    {0, {0, 0, 0}, 0}, // 23
    {0, {0, 0, 0}, 0}, // 24
    {0, {0, 0, 0}, 0}, // 25
    {0, {0, 0, 0}, 0}, // 26
    {0, {0, 0, 0}, 0}, // 27
    {0, {0, 0, 0}, 0}, // 28
    {0, {0, 0, 0}, 0}, // 29
    {0, {0, 0, 0}, 0}, // 30
    {0, {0, 0, 0}, 0}  // 31
};

void interrupt_handler(struct isr_param *isr_param)
{
    printf("Oh no %d!\r\n", isr_param->int_vector);
}

struct idt_entry create_idt_entry(struct idt_entry_descriptor descriptor)
{
    struct idt_entry res = { 0 };

    res.selector = descriptor.selector;
    res.offset_1 = descriptor.offset & 0xffff;
    res.offset_2 = (descriptor.offset >> 16) & 0xffff;

    res.type = descriptor.type;
    res.size = 1;
    res.desc_priv = 0;
    res.present = 1;

    return res;
}

static void create_idt(void)
{
    for (int i = 0; i < IDT_NB_ENTRIES; ++i)
    {
        struct idt_entry entry = create_idt_entry(idt_entries_descriptors[i]);
        idt.entries[i] = entry;
    }
}


static void load_idt(void)
{
    struct idt_r idtr;
    idtr.addr = (uint32_t)&idt;
    idtr.limit = IDT_SIZE - 1;

    asm volatile("lidt %0\n"
                 :
                 : "m" (idtr)
                 : "memory");
}

void init_idt(void)
{
    create_idt();
    load_idt();
}