@@ -1,50 +0,0 @@
-.section .text
-
-  # disable interrupts
-  cli
-
-  # canonicalize %CS:%EIP to a known value
-  ljmp $0, $start
-start:
-
-  # setup segments
-  mov $0x0000, %ax
-  mov %ax, %ss
-  mov %ax, %ds
-  mov %ax, %es
-  mov %ax, %fs
-
-  # setup stack
-  mov $0x9000, %ax
-  mov %ax, %bp
-  mov %ax, %sp
-
-  # select display page 0
-  movb $0, %al
-  movb 0x05, %ah
-  int $0x10
-
-  # print hello world
-  mov $message, %si
-  mov $0x0000, %bx
-  mov $0x0E, %ah
-
-print_loop:
-  lodsb
-  or %al, %al
-  jz print_end
-  int $0x10
-  jmp print_loop
-print_end:
-
-  # loop forever
-loop:
-  jmp loop
-
-  # some data
-  message: .ascii "Hello World!\n\0"
-
-end:
-  .=510
-  .byte 0x55
-  .byte 0xAA

@@ -0,0 +1,61 @@
+.section .text
+
+  # disable interrupts
+  cli
+
+  # canonicalize %CS:%EIP to a known value
+  ljmp $0, $start
+start:
+
+  # setup segments
+  mov $0x0000, %ax
+  mov %ax, %ss
+  mov %ax, %ds
+  mov %ax, %es
+  mov %ax, %fs
+
+  # setup stack
+  mov $0x9000, %ax
+  mov %ax, %bp
+  mov %ax, %sp
+
+  # select display page 0
+  mov $0, %al
+  mov $0x05, %ah
+  int $0x10
+
+  # print hello world
+  mov $message, %si
+  mov $0x0000, %bx
+  mov $0x0E, %ah
+
+print_loop:
+  lodsb
+  or %al, %al
+  jz print_end
+  int $0x10
+  jmp print_loop
+print_end:
+
+  # TODO:
+  # - load kernel into memory starting at adress 0x10000
+  #   (NOTE: this code can only be jumped to after loading the global descriptor table
+  #          because it uses absolute adresses larger than 16 bit)
+  # - load global descriptor table and far jump into protected mode
+  # - activate A20 gate
+  # - jump to low kernel code
+
+  # loop forever
+
+loop:
+  jmp loop
+
+  # some data
+message: 
+  .ascii " Hello World!"
+  .byte 0x00
+
+end:
+  .=510
+  .byte 0x55
+  .byte 0xAA

@@ -0,0 +1,5 @@
+.RECIPEPREFIX = >
+
+.PHONY: build
+build: boot.s
+> $(GCC_PREFIX)as -o $(BUILD_DIR)/boot.o boot.s

@@ -6,13 +6,20 @@ PAGE_SIZE = 1 << 12;
 
 MEMORY
 {
-  BOOT :        ORIGIN = 0x00007C00, LENGTH = 0x00000300
+  BOOT :          ORIGIN = 0x00007C00, LENGTH = 0x00000200
+  SECOND_STAGE :  ORIGIN = 0x00010000, LENGTH = 0x00090000
 }
 
 SECTIONS
 {
-  BOOT :
+  BOOT : AT(0x0000)
   {
     build/boot.o(.text)
   } >BOOT
+
+  SECOND_STAGE : AT(ADDR(BOOT) + SIZEOF(BOOT))
+  {
+    build/second_stage.o(.text)
+    build/second_stage.o(.data)
+  } >SECOND_STAGE
 }

@@ -1,16 +1,18 @@
 .RECIPEPREFIX = >
 
-CURRENT_DIR		= $(shell pwd)
-BUILD_DIR		= $(CURRENT_DIR)/build
+export CURRENT_DIR		= $(shell pwd)
+export BUILD_DIR		= $(CURRENT_DIR)/build
 
-GCC_PREFIX		= $(HOME)/opt/cross/i686-elf-/bin/i686-elf-
-GCC_OPTIONS		= -O0 -std=c++0x -Wno-write-strings -Wall -Wextra -fno-exceptions -fno-rtti -ffreestanding
+export GCC_PREFIX		= $(HOME)/opt/cross/i686-elf-/bin/i686-elf-
+export GCC_OPTIONS		= -O0 -std=c++0x -Wno-write-strings -Wall -Wextra -fno-exceptions -fno-rtti -ffreestanding
 
 # OBJ_FILES = $(wildcard obj/asm/*.o) $(wildcard obj/cpp/*.o)
 
 .PHONY: build
-build: $(BUILD_DIR)/base.img
-> 
+build:
+> $(MAKE) -C boot build
+> $(MAKE) -C second_stage build
+> $(GCC_PREFIX)ld -T link.txt -Map=mapfile.txt -o $(BUILD_DIR)/base.img --oformat binary
 
 .PHONY: clear
 clear:
@@ -22,11 +24,5 @@ > ./run.sh
 
 .PHONY: rebuild
 rebuild:
-> make clear
-> make build
-
-$(BUILD_DIR)/base.img: $(BUILD_DIR)/boot.o
-> $(GCC_PREFIX)ld -T link.txt -Map=mapfile.txt -o $(BUILD_DIR)/base.img --oformat binary
-
-$(BUILD_DIR)/boot.o: boot.s
-> $(GCC_PREFIX)as -o $(BUILD_DIR)/boot.o boot.s+> $(MAKE) clear
+> $(MAKE) build

@@ -0,0 +1,3 @@
+start:
+loop:
+  ljmp $0,$loop

@@ -0,0 +1,8 @@
+.RECIPEPREFIX = >
+
+.PHONY: build
+build: build/entry.o
+> $(GCC_PREFIX)ld -i build/entry.o -o $(BUILD_DIR)/second_stage.o --oformat elf32-i386
+
+build/entry.o: entry.s
+> $(GCC_PREFIX)as -o $@ $?