toaruos/kernel/cpu/idt.c
2015-05-20 03:12:20 -04:00

64 lines
1.2 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2011-2013 Kevin Lange
*
* Interrupt Descriptor Tables
*
*/
#include <system.h>
#include <logging.h>
/*
* IDT Entry
*/
struct idt_entry {
unsigned short base_low;
unsigned short sel;
unsigned char zero;
unsigned char flags;
unsigned short base_high;
} __attribute__((packed));
/*
* IDT pointer
*/
struct idt_ptr {
unsigned short limit;
uintptr_t base;
} __attribute__((packed));
struct idt_entry idt[256];
struct idt_ptr idtp;
extern void idt_load(unsigned int);
/*
* idt_set_gate
* Set an IDT gate
*/
void idt_set_gate(
unsigned char num,
void (*base)(void),
unsigned short sel,
unsigned char flags
) {
idt[num].base_low = ((uintptr_t)base & 0xFFFF);
idt[num].base_high = ((uintptr_t)base >> 16) & 0xFFFF;
idt[num].sel = sel;
idt[num].zero = 0;
idt[num].flags = flags | 0x60;
}
/*
* idt_install
* Install the IDTs
*/
void idt_install(void) {
idtp.limit = (sizeof(struct idt_entry) * 256) - 1;
idtp.base = (uintptr_t)&idt;
memset(&idt, 0, sizeof(struct idt_entry) * 256);
idt_load((unsigned int)&idtp);
}