limine/common/sys/idt.c
2022-02-03 10:38:43 +01:00

70 lines
1.8 KiB
C

#include <stdint.h>
#include <stddef.h>
#include <sys/idt.h>
#include <sys/cpu.h>
#include <sys/pic.h>
#include <sys/lapic.h>
#include <mm/pmm.h>
#include <lib/blib.h>
static struct idt_entry *dummy_idt = NULL;
void dummy_isr(void);
void init_flush_irqs(void) {
size_t dummy_idt_size = 256 * sizeof(struct idt_entry);
dummy_idt = ext_mem_alloc(dummy_idt_size);
for (size_t i = 0; i < 256; i++) {
dummy_idt[i].offset_lo = (uint16_t)(uintptr_t)dummy_isr;
dummy_idt[i].type_attr = 0x8e;
#if defined (__i386__)
dummy_idt[i].selector = 0x18;
dummy_idt[i].offset_hi = (uint16_t)((uintptr_t)dummy_isr >> 16);
#elif defined (__x86_64__)
dummy_idt[i].selector = 0x28;
dummy_idt[i].offset_mid = (uint16_t)((uintptr_t)dummy_isr >> 16);
dummy_idt[i].offset_hi = (uint32_t)((uintptr_t)dummy_isr >> 32);
#endif
}
pmm_free(dummy_idt, dummy_idt_size);
}
int irq_flush_type = IRQ_NO_FLUSH;
void flush_irqs(void) {
switch (irq_flush_type) {
case IRQ_PIC_ONLY_FLUSH:
pic_flush();
// FALLTHRU
case IRQ_NO_FLUSH:
return;
case IRQ_PIC_APIC_FLUSH:
break;
default:
panic(false, "Invalid IRQ flush type");
}
struct idtr old_idt;
asm volatile ("sidt %0" : "=m"(old_idt) :: "memory");
struct idtr new_idt = {
256 * sizeof(struct idt_entry) - 1,
(uintptr_t)dummy_idt
};
asm volatile ("lidt %0" :: "m"(new_idt) : "memory");
// Flush the legacy PIC so we know the remaining ints come from the LAPIC
pic_flush();
asm volatile ("sti" ::: "memory");
// Delay a while to make sure we catch ALL pending IRQs
delay(10000000);
asm volatile ("cli" ::: "memory");
asm volatile ("lidt %0" :: "m"(old_idt) : "memory");
}