Rename main entry point to kernel_main(), Fix descriptor tables not g…

…etting initialized, Disable stack protector (GCC)

Makefile

@@ -4,7 +4,7 @@
 BIN = bin
 SRC = src
 CC = gcc
-CFLAGS = -Wall -ffreestanding -m32 -std=gnu99 -ggdb3
+CFLAGS = -Wall -ffreestanding -fno-stack-protector -m32 -std=gnu99 -ggdb3
 LINK = ld
 LINKFLAGS = -melf_i386 -Tlink.ld
 CASM = nasm

gdb.gdb

@@ -7,5 +7,5 @@ define hook-stop
     printf "\n"
 end
 
-break main
+break kernel_main
 continue

src/gdt.asm

@@ -1,4 +1,6 @@
-; Sets up global descriptor table and interrupt descriptor table.
+; Sets up global descriptor table and interrupt descriptor table
+
+[BITS 32]                   ; All instructions 32-bit
 
 [GLOBAL gdt_flush]          ; Make 'gdt_flush' accessible from C
 

src/interrupt.asm

@@ -1,4 +1,6 @@
-; Contains interrupt service routine wrappers.
+; Contains interrupt service routine wrappers
+
+[BITS 32]               ; All instructions 32-bit
 
 ; Macro creating a stub for an ISR which does NOT pass it's own error code (adds a dummy errcode byte)
 %macro ISR_NOERRCODE 1

src/main.c

@@ -1,15 +1,18 @@
 #include "monitor.h"
+#include "descriptor_tables.h"
 
 struct multiboot;
 
 int kernel_main(struct multiboot *mboot_ptr) {
+    init_descriptor_tables();
+
     monitor_clear();
     monitor_write("Welcome to Tyr (");
     monitor_write_hex(0x547972);
     monitor_write("), the one-handed OS!\n");
 
     asm volatile("int $0x3");
-    //asm volatile("int $0x4");
+    asm volatile("int $0x4");
 
     return 0;
 }