49 lines
993 B
C
Executable File
49 lines
993 B
C
Executable File
#include <kernel/init.h>
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#include <string.h>
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#include <sys/io.h>
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#include "gdt.h"
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int tss[16][2];
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void NMI_disable(void) {
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outb(0x70, inb(0x70) | 0x80);
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}
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void NMI_enable(void) {
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outb(0x70, inb(0x70) & 0x7F);
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}
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void A20_enable(void) {
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unsigned short int a = inb(0x92);
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if((a & 2) != 0) {
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return;
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}
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a |= 2;
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outb(a, 0x92);
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}
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void setup_gdt(void) {
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struct GDT gdt[4];
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gdt[0].base = 0; gdt[0].limit = 0; gdt[0].type = 0;
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gdt[1].base = 0; gdt[1].limit = 0xFFFFFFFF; gdt[1].type = 0x9A;
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gdt[2].base = 0; gdt[2].limit = 0xFFFFFFFF; gdt[2].type = 0x92;
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gdt[3].base = (unsigned int) tss; gdt[3].limit=sizeof(tss); gdt[3].type = 0x89;
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unsigned short int GDT[4];
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encode_gdt_entry(&GDT[0], gdt[0]);
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encode_gdt_entry(&GDT[1], gdt[1]);
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encode_gdt_entry(&GDT[2], gdt[2]);
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encode_gdt_entry(&GDT[3], gdt[3]);
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set_gdt(GDT, sizeof(GDT));
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}
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int init(void) {
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NMI_disable();
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A20_enable();
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setup_gdt();
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printf("Fenix Dev Pre-release v0.0.3\n");
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return 0;
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}
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