Now actually runs.

.gdbinit

@@ -0,0 +1,3 @@
+file kernel.bin
+target remote localhost:1234
+set step-mode on

Makefile

@@ -19,7 +19,7 @@ CX:=$(ENV)/$(TARGET)-g++
 AS:=nasm
 LD:=$(ENV)/$(TARGET)-ld
 
-CFLAGS:=-Wall -Wextra -Werror -nostdlib -nostartfiles -nodefaultlibs -std=c99
+CFLAGS:=-Wall -Werror -nostdlib -nostartfiles -nodefaultlibs -std=c99 -g
 CFLAGS+=-I ./include
 LFLAGS:=-nostdlib -nostartfiles -nodefaultlibs
 
@@ -60,8 +60,14 @@ hdd.img: kernel.bin
 	@mcopy -i hdd_temp.img dst/syslinux.cfg ::syslinux.cfg
 	@mv hdd_temp.img hdd.img
 
-emulate-nohdd: kernel.bin
+emulate-nohdd-debug: kernel.bin
+	@echo "[i] Starting GDB..."
+	@gnome-terminal -x /bin/bash -c "gdb"
 	@echo "[i] Starting QEmu..."
+	@qemu -kernel kernel.bin -S -gdb tcp::1234
+
+emulate-nohdd: kernel.bin
+	@echo "[i] Starting QEMU..."
 	@qemu -kernel kernel.bin
 
 emulate: hdd.img

include/Tier0/paging.h

@@ -1,6 +1,6 @@
 #ifndef __PAGING_H__
 #define __PAGING_H__
 
-void init_simple_paging(void);
+void paging_init_simple(void);
 
 #endif

src/Tier0/_start.asm

@@ -15,9 +15,11 @@ STACKSIZE equ 0x4000
 ; ############################## text segment #################################
 ; #############################################################################
 
-section .text
+section .setup
 align 4
 
+global g_before_gdt
+
 ; Multiboot header
 MultiBootHeader:
     dd MAGIC
@@ -27,15 +29,18 @@ MultiBootHeader:
 ; Actual entry point
 _start:
     lgdt [falsegdt]
-    mov ax, 0x10
+    mov cx, 0x10
-    mov ds, ax
+    mov ds, cx
-    mov es, ax
+    mov es, cx
-    mov fs, ax
+    mov fs, cx
-    mov gs, ax
+    mov gs, cx
-    mov ss, ax
+    mov ss, cx
-
+g_before_gdt:
     jmp 0x08:higherhalf
 
+section .text
+align 4
+
 higherhalf:    
     mov esp, kstack + STACKSIZE
     

src/Tier0/kmain.c

@@ -6,8 +6,9 @@
 // Real kernel entry point, called from _start.asm
 void kmain(void *mbd, u32 magic)
 {
-    init_simple_paging();
+    kclear();
-    gdt_create_flat();
+    kprintf("[i] Welcome to Cucumber!\n\n");
+    kprintf("[i] Magic from bootloader: 0x%x.\n", magic);
 
     if (magic != 0x2BADB002)
     {
@@ -15,10 +16,7 @@ void kmain(void *mbd, u32 magic)
         return;
     }
 
-    char *szBootLoaderName = (char *)((u32 *)mbd)[16];
+    paging_init_simple();
-
+    gdt_create_flat();
-    kclear();
-    kprintf("[i] Booting via %s.\n", szBootLoaderName);
-    
 }
 

src/Tier0/kstdio.c

@@ -101,9 +101,9 @@ void kscroll_up(void)
    if (g_kstdio_cur_y >= 25)
    {
         Temp = g_kstdio_cur_y - 25 + 1;
-        kmemcpy((void*)0xB8000, (void*)(0xB8000 - Temp * 80 * 2), (25 - Temp) * 80 * 2);
+        kmemcpy((void*)0xC00B8000, (void*)(0xC00B8000 - Temp * 80 * 2), (25 - Temp) * 80 * 2);
 
-        kmemsetw((void*)(0xB8000 + (25 - Temp) * 80), Blank, 80);
+        kmemsetw((void*)(0xC00B8000 + (25 - Temp) * 80), Blank, 80);
         g_kstdio_cur_y = 25 - 1;
    }
 }
@@ -175,7 +175,7 @@ void kdump(u8 *bData, u32 Length)
 
 void kputch(s8 Character)
 {
-    volatile u8 *VideoMemory = (u8 *)0xB8000;
+    volatile u8 *VideoMemory = (u8 *)0xC00B8000;
     u16 Offset = (g_kstdio_cur_y * 80 + g_kstdio_cur_x) << 1;
 
     if (Character == '\n')
@@ -207,7 +207,7 @@ void kprint(s8 *szString)
 
 void kclear(void)
 {
-    volatile u8 *VideoMemory = (u8 *)0xB8000;
+    volatile u8 *VideoMemory = (u8 *)0xC00B8000;
     u32 Size = (80 * 25 ) << 1;
     for (u32 i = 0; i < Size; i += 2)
     {

src/Tier0/paging.c

@@ -1,24 +1,58 @@
 #include "Tier0/paging.h"
+#include "Tier0/kstdio.h"
 #include "types.h"
 
 u32 g_kernel_page_directory[1024] __attribute__ ((aligned (4096)));
 u32 g_low_page_table[1024] __attribute__ ((aligned (4096)));
 
-void init_simple_paging(void)
+/*u8 paging_get_physical(u32 Virtual, u32 *Physical)
+{
+    u16 Index = 
+
+    u32 DirectoryEntry = g_kernel_page_directory[Index];
+
+    u8 TablePresent = DirectoryEntry & 0b1;
+
+    if (!TablePresent) 
+        return 0;
+
+    u32 TableAddress = 0;
+    TableAddress |= (DirectoryEntry & 0xFFFFF000);
+
+    u32 Table = *((u32 *) &TableAddress);
+
+    u8 PagePresent = DirectoryEntry &
+}*/
+
+void paging_dump_directory(void)
+{
+    for (u32 i = 0; i < 10; i++)
+    {
+        kprintf("[i] Virtual 0x%X - 0x%X, Entry 0x%X.\n", i * 4096 * 1024, (i + 1) * 4096 * 1024, g_kernel_page_directory[i] & 0xFFFFF000);
+    }
+}
+
+void paging_init_simple(void)
 {
     void *RealKernelPageDir = (u8 *)g_kernel_page_directory + 0x40000000;
     void *RealLowPageTable = (u8 *)g_low_page_table + 0x40000000;
 
     for (u16 i = 0; i < 1024; i++)
     {
-        g_kernel_page_directory[i] = (i * 4096) | 0x03;
+        g_low_page_table[i] = (i * 4096) | 0x03;
-        g_low_page_table[i] = 0;
+        g_kernel_page_directory[i] = 0;
     }
 
+    kprintf("[i] Page Directory Physical: 0x%X, Virtual: 0x%X.\n", RealKernelPageDir, g_kernel_page_directory);
+    kprintf("[i] Low Page Table Physical: 0x%X, Virtual: 0x%X.\n", RealLowPageTable, g_low_page_table);
+
     g_kernel_page_directory[0] = (u32)RealLowPageTable | 0x03;
     g_kernel_page_directory[768] = (u32)RealLowPageTable | 0x03;
+    
+    paging_dump_directory();
 
-    __asm__ volatile (  "mov %0, %%eax\n"
+
+    __asm volatile (  "mov %0, %%eax\n"
                     "mov %%eax, %%cr3\n"
                     "mov %%cr0, %%eax\n"
                     "orl $0x80000000, %%eax\n"

src/kernel.ld

@@ -1,31 +1,48 @@
 OUTPUT_FORMAT("elf32-i386")
 ENTRY(_start)
 
+Offset  = 0x00100000;
+LMA     = 0x00000000;
+VMA     = 0xC0000000;
+
 SECTIONS
 {
-    . = 0x100000;
+    . = Offset;
-    .setup :
+
+    g_setup_gdt_ptr = g_gdt_ptr - VMA;
+    g_setup_gdt_entries = g_gdt_entries - VMA;
+
+    .setup LMA + Offset : AT(LMA + Offset)
     {
         *(.setup)
+        . = ALIGN(0x1000);
     }
 
-    . += 0xC0000000;
+    . += VMA;
 
-    .text : AT(ADDR(.text) - 0xC0000000)
+    .text : AT(g_section_code)
     {
+        g_section_code = . - VMA;
         *(.text)
+        . = ALIGN(0x1000);
     }
     
-    .data ALIGN (4096) : AT(ADDR(.data) - 0xC0000000)
+    .data : AT(g_section_data)
     {
+        g_section_data = . - VMA;
         *(.data)
         *(.rodata*)
+        . = ALIGN(0x1000);
     }
     
-    .bss ALIGN (4096) : AT(ADDR(.bss) - 0xC0000000)
+    .bss : AT(g_section_bss)
     {
+        g_section_bss = . - VMA;
         *(COMMON*)
         *(.bss*)
+        . = ALIGN(0x1000);
     }
+
+    . = ALIGN(0x1000);
 }