hackthelobby/libcaca/kernel/boot/idt.c

152 lines
4.3 KiB
C

/*
* libcaca Colour ASCII-Art library
* Copyright (c) 2006 Sam Hocevar <sam@hocevar.net>
* 2009 Jean-Yves Lamoureux <jylam@lnxscene.org>
* All Rights Reserved
*
* This library is free software. It comes without any warranty, to
* the extent permitted by applicable law. You can redistribute it
* and/or modify it under the terms of the Do What the Fuck You Want
* to Public License, Version 2, as published by Sam Hocevar. See
* http://www.wtfpl.net/ for more details.
*/
/*
*'freely' inspired by http://jojo.ouvaton.org/dossiers/boot_sector/tutorial02.html
* (actually, that's mostly copied, with minor compilation fixes)
*/
#include "kernel.h"
#include "klibc.h"
#define IDTBASE 0 /* GDT Physical address */
#define IDTSIZE 256 /* Max descriptor count */
#define INTGATE 0x8E00 /* Interruptions */
#define TRAPGATE 0x8F00 /* Syscalls */
#define TASKGATE 0x8500 /* Task switching */
/* segment descriptor */
struct idtdesc
{
u16 offset0_15;
u16 select;
u16 type;
u16 offset16_31;
} __attribute__ ((packed));
/* IDTR register */
struct idtr
{
u16 limite;
u32 base;
} __attribute__ ((packed));
struct idtr kidtr;
/* IDT table */
struct idtdesc kidt[IDTSIZE] = { {0, 0, 0, 0} };
/* pointer on a free IDT entry */
unsigned int kidtptr = 0;
void default_int(void);
void k_int0(void);
void k_int1(void);
void k_int2(void);
void k_int3(void);
void k_int4(void);
void k_int5(void);
void k_int6(void);
void k_int7(void);
void k_int8(void);
void k_int9(void);
void k_int10(void);
void k_int11(void);
void k_int12(void);
void k_int13(void);
void k_int14(void);
void k_int15(void);
void k_int16(void);
void k_int17(void);
void k_int18(void);
void k_irq0(void);
void k_irq1(void);
void k_irq2(void);
void k_irq3(void);
void k_irq4(void);
void k_irq5(void);
void k_irq6(void);
void k_irq7(void);
void k_irq8(void);
void init_idt_desc(u32 offset, u16 select, u16 type, struct idtdesc *desc)
{
desc->offset0_15 = (offset & 0xffff);
desc->select = select;
desc->type = type;
desc->offset16_31 = (offset & 0xffff0000) >> 16;
return;
}
void add_idt_desc(struct idtdesc desc)
{
kidt[kidtptr++] = desc;
return;
}
void init_idt(void)
{
struct idtdesc desc;
int i;
for (i = 0; i < IDTSIZE; i++)
{
init_idt_desc((u32) default_int, 0x08, INTGATE, &desc);
add_idt_desc(desc);
}
init_idt_desc((u32) k_int0, 0x08, INTGATE, &kidt[0]);
init_idt_desc((u32) k_int1, 0x08, INTGATE, &kidt[1]);
init_idt_desc((u32) k_int2, 0x08, INTGATE, &kidt[2]);
init_idt_desc((u32) k_int3, 0x08, INTGATE, &kidt[3]);
init_idt_desc((u32) k_int4, 0x08, INTGATE, &kidt[4]);
init_idt_desc((u32) k_int5, 0x08, INTGATE, &kidt[5]);
init_idt_desc((u32) k_int6, 0x08, INTGATE, &kidt[6]);
init_idt_desc((u32) k_int7, 0x08, INTGATE, &kidt[7]);
init_idt_desc((u32) k_int8, 0x08, INTGATE, &kidt[8]);
init_idt_desc((u32) k_int9, 0x08, INTGATE, &kidt[9]);
init_idt_desc((u32) k_int10, 0x08, INTGATE, &kidt[10]);
init_idt_desc((u32) k_int11, 0x08, INTGATE, &kidt[11]);
init_idt_desc((u32) k_int12, 0x08, INTGATE, &kidt[12]);
init_idt_desc((u32) k_int13, 0x08, INTGATE, &kidt[13]);
init_idt_desc((u32) k_int14, 0x08, INTGATE, &kidt[14]);
init_idt_desc((u32) k_int15, 0x08, INTGATE, &kidt[15]);
init_idt_desc((u32) k_int16, 0x08, INTGATE, &kidt[16]);
init_idt_desc((u32) k_int17, 0x08, INTGATE, &kidt[17]);
init_idt_desc((u32) k_int18, 0x08, INTGATE, &kidt[18]);
init_idt_desc((u32) k_irq0, 0x08, INTGATE, &kidt[32]);
init_idt_desc((u32) k_irq1, 0x08, INTGATE, &kidt[33]);
init_idt_desc((u32) k_irq2, 0x08, INTGATE, &kidt[34]);
init_idt_desc((u32) k_irq3, 0x08, INTGATE, &kidt[35]);
init_idt_desc((u32) k_irq4, 0x08, INTGATE, &kidt[36]);
init_idt_desc((u32) k_irq5, 0x08, INTGATE, &kidt[37]);
init_idt_desc((u32) k_irq6, 0x08, INTGATE, &kidt[38]);
init_idt_desc((u32) k_irq7, 0x08, INTGATE, &kidt[39]);
init_idt_desc((u32) k_irq8, 0x08, INTGATE, &kidt[40]);
kidtr.limite = IDTSIZE * 8;
kidtr.base = IDTBASE;
memcpy((void *)kidtr.base, kidt, kidtr.limite);
#define printf(format, ...) { char __str[255]; sprintf (__str, format, __VA_ARGS__); print(__str);}
printf("Loading IDT from 0x%x\n", kidtr);
#undef printf
asm("lidtl (kidtr)");
}