we got the gdt working!

This commit is contained in:
Gitea 2020-12-18 12:38:32 -06:00
parent da7123e518
commit c79e957f38
6 changed files with 56 additions and 19 deletions

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@ -1,3 +1,5 @@
#include "gdt.h"
void encode_gdt_entry(unsigned short int * target, struct GDT source) {
if((source.limit > 65536) && ((source.limit & 0xFFF) != 0xFFF)) {
/* This needs to error out. */
@ -25,4 +27,4 @@ void encode_gdt_entry(unsigned short int * target, struct GDT source) {
/* Encode type */
target[5] = source.type;
}
}

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@ -8,7 +8,7 @@ struct GDT {
};
void encode_gdt_entry(unsigned short int *, struct GDT);
extern void set_gdt(void);
extern void set_gdt(unsigned short int[], int);
extern void reload_segments(void);
#endif

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@ -6,24 +6,20 @@ gdtr:
.int 0
set_gdt:
.fnstart
.func set_gdt
mov 4(%esp), %eax
mov %eax, 2($gdtr)
mov %eax, gdtr+2
mov 8(%esp), %ax
mov %ax, $gdtr
lgdt $gdtr
mov %ax, gdtr
lgdt gdtr
ret
.fnend
.endfunc
.globl reload_segments
.type reload_segments,%function
reload_segments:
.fnstart
jmp 0x08:reload_CS
.fnend
reload_CS:
.func reload_segments
mov 0x10, %ax
mov %ax, %ds
mov %ax, %es
@ -31,4 +27,4 @@ reload_CS:
mov %ax, %gs
mov %ax, %ss
ret
.endfunc

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@ -3,6 +3,10 @@
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/io.h>
#include "gdt.h"
int tss[16][2];
int test_libc(void) {
int failed = 0;
@ -10,12 +14,8 @@ int test_libc(void) {
printf("==Testing stdio.h==\n");
printf("printf(\"%%d\", 10): %d (expected 10)\n", 10);
printf("printf(\"%%d\", -10): %d (expected -10)\n", -10);
printf("printf(\"%%i\", 10): %d (expected 10)\n", 10);
printf("printf(\"%%o\", 014): %o (expected 14)\n", 014);
printf("printf(\"%%o\", 14): %o (expected 16)\n", 14);
printf("printf(\"%%u\", 10): %u (expected 10)\n", 10);
printf("printf(\"%%x\", 0xC9A): %x (expected c9a)\n", 0xC9A);
printf("printf(\"%%x\", 26): %x (expected 1a)\n", 26);
printf("printf(\"%%X\", 0xC9A): %x (expected C9A)\n", 0xC9A);
printf("printf(\"%%p\", &i): %p (expected 0x[hex])\n", &failed);
@ -95,12 +95,48 @@ int test_libc(void) {
}
printf("Tests failed: %d\n", failed);
printf("One final test: If you can see this, the TTY can scroll.");
return failed;
}
void NMI_disable(void) {
outb(0x70, inb(0x70) | 0x80);
}
void NMI_enable(void) {
outb(0x70, inb(0x70) & 0x7F);
}
void A20_enable(void) {
unsigned short int a = inb(0x92);
if((a & 2) != 0) {
return;
}
a |= 2;
outb(a, 0x92);
}
void setup_gdt(void) {
struct GDT gdt[4];
gdt[0].base = 0; gdt[0].limit = 0; gdt[0].type = 0;
gdt[1].base = 0; gdt[1].limit = 0xFFFFFFFF; gdt[1].type = 0x9A;
gdt[2].base = 0; gdt[2].limit = 0xFFFFFFFF; gdt[2].type = 0x92;
gdt[3].base = (unsigned int) tss; gdt[3].limit=sizeof(tss); gdt[3].type = 0x89;
unsigned short int GDT[4];
encode_gdt_entry(&GDT[0], gdt[0]);
encode_gdt_entry(&GDT[1], gdt[1]);
encode_gdt_entry(&GDT[2], gdt[2]);
encode_gdt_entry(&GDT[3], gdt[3]);
set_gdt(GDT, sizeof(GDT));
}
int init(void) {
NMI_disable();
A20_enable();
setup_gdt();
printf("Fenix Dev Pre-release v0.0.3\n");
return test_libc();
}

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@ -3,4 +3,4 @@ KERNEL_ARCH_CPPFLAGS=
KERNEL_ARCH_LDFLAGS=
KERNEL_ARCH_LIBS=
KERNEL_ARCH_OBJS=$(ARCHDIR)/boot.o $(ARCHDIR)/tty.o $(ARCHDIR)/init.o $(ARCHDIR)/cmos.o
KERNEL_ARCH_OBJS=$(ARCHDIR)/boot.o $(ARCHDIR)/tty.o $(ARCHDIR)/init.o $(ARCHDIR)/cmos.o $(ARCHDIR)/gdt.o $(ARCHDIR)/gdt_load.o

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@ -3,6 +3,9 @@
#include <stdio.h>
extern int tss[16][2];
extern unsigned short int * GDT;
int test_libc(void);
int init(void);