Files
novaos/kernel/arch/idt/idt.c

54 lines
1.2 KiB
C

#include <stdbool.h>
#ifdef __TESTING__
#include <kernel/_kernel.h>
#endif
#include <kernel/x86/idt.h>
__attribute__((aligned(0x10)))
static idt_entry_t idt[256];
static idtr_t idtr;
static bool vectors[IDT_MAX_DESCRIPTORS];
void exception_handler()
{
__asm__ volatile ("cli; hlt"); // hangs the computer
}
void idt_set_descriptor(uint8_t vector, void *isr, uint8_t flags)
{
idt_entry_t* descriptor = &idt[vector];
descriptor->isr_low = (uint32_t) isr & 0xFFFF;
descriptor->kernel_cs = 0x08; // this is whatever the kernel code selector is in the GDT
descriptor->attributes = flags;
descriptor->isr_high = (uint32_t) isr >> 16;
descriptor->reserved = 0;
}
extern void* isr_stub_table[];
void idt_init(void)
{
#ifdef __TESTING__
kinfo("Initializing the IDT");
#endif
idtr.base = (uintptr_t)&idt[0];
idtr.limit = (uint16_t) sizeof(idt_entry_t) * IDT_MAX_DESCRIPTORS - 1;
for (uint8_t vector = 0; vector < 32; vector++) {
idt_set_descriptor(vector, isr_stub_table[vector], 0x8E);
vectors[vector] = true;
}
// The "m" indicates actual data, not a pointer
__asm__ volatile("lidt %0" : : "m"(idtr)); // load the new IDT
__asm__ volatile("sti"); // set the interrupt flag
#ifdef __TESTING__
kinfo("Initialized the IDT");
#endif
}