Bootloader do some directory restructuring

bootloader/bios/boot.S

@@ -0,0 +1,170 @@
+.code16
+
+#########################################
+#
+# STAGE 1 BOOTLOADER
+#
+# its sole purpose is to load stage2 from
+# bios boot partition
+#
+#########################################
+
+.section .stage1
+
+.global stage1_main
+stage1_main:
+	# setup segments
+	movw $0, %ax
+	movw %ax, %ds
+	movw %ax, %es
+
+	# setup stack
+	movw %ax, %ss
+	movl $0x7C00, %esp
+
+	# save boot disk number
+	call read_stage2_into_memory
+
+	jmp stage2_main
+
+.global print_and_halt
+print_and_halt:
+	call puts
+halt:
+	hlt
+	jmp halt
+
+
+#########################################
+#
+# STAGE 2 BOOTLOADER
+#
+#########################################
+
+.section .stage2
+
+stage2_main:
+	# clear screen and enter 80x25 text mode
+	movb $0x03, %al
+	movb $0x00, %ah
+	int $0x10
+
+	# print hello message
+	movw $hello_msg, %si
+	call puts; call print_newline
+
+	call enter_unreal_mode
+	movw $unreal_enter_msg, %si
+	call puts; call print_newline
+
+	call get_memory_map
+	call read_user_command_line
+	
+	call vesa_find_video_mode
+
+	call print_newline
+
+	movw $start_kernel_load_msg, %si
+	call puts; call print_newline
+
+	call print_memory_map
+
+	call find_root_disk
+	call find_root_partition
+
+	call print_root_partition_info
+	call print_newline
+
+	call has_ext2_filesystem
+	testb %al, %al
+	jz print_and_halt
+
+	call ext2_find_kernel
+	movl $ext2_inode_read_bytes, %esi
+
+	call elf_read_kernel_to_memory
+
+	call vesa_set_target_mode
+
+	cli
+
+	# setup protected mode
+	movl %cr0, %ebx
+	orb $1, %bl
+	movl %ebx, %cr0
+
+	# jump to kernel in protected mode
+	ljmpl $0x18, $protected_mode
+
+
+.code32
+protected_mode:
+	movw $0x10, %bx
+	movw %bx, %ds
+	movw %bx, %es
+	movw %bx, %fs
+	movw %bx, %gs
+	movw %bx, %ss
+
+	movl %eax, %ecx
+
+	movl $0xD3C60CFF, %eax
+	movl $banan_boot_info, %ebx
+	xorl %edx, %edx
+	xorl %esi, %esi
+	xorl %edi, %edi
+
+	jmp *%ecx
+
+
+.code16
+enter_unreal_mode:
+	cli
+	pushw %ds
+
+	lgdt gdtr
+
+	movl %cr0, %eax
+	orb $1, %al
+	movl %eax, %cr0
+	ljmpl $0x8, $.enter_unreal_mode_pmode
+
+ .enter_unreal_mode_pmode:
+	movw $0x10, %bx
+	movw %bx, %ds
+
+	andb 0xFE, %al
+	movl %eax, %cr0
+	ljmpl $0x0, $.enter_unreal_mode_unreal
+
+ .enter_unreal_mode_unreal:
+	popw %ds
+	sti
+
+	ret
+
+hello_msg:
+	.asciz "This is banan-os bootloader"
+
+unreal_enter_msg:
+	.asciz "Entered unreal mode"
+
+start_kernel_load_msg:
+	.asciz "Starting to load kernel"
+
+gdt:
+	.quad 0x0000000000000000
+	.quad 0x00009A000000FFFF
+	.quad 0x00CF92000000FFFF
+	.quad 0x00CF9A000000FFFF
+gdtr:
+	.short . - gdt - 1
+	.quad gdt
+
+banan_boot_info:
+	boot_command_line:
+		.long command_line
+	boot_framebuffer:
+		.long framebuffer
+	boot_memory_map:
+		.long memory_map