start.s.svn-base

SImple Microkernel Distributed Operating System

SECTION .text
BITS 32
global start
start:
	mov esp, sys_stack
	jmp init

init:
extern  main
extern  install_desc
	
	call	install_desc
	call    main
	jmp	$
	
global	gdt_flush
gdt_flush:
	cld
	lgdt	[app_gdt_ram]
	mov	ebx, cr0
	or	ebx, pe_bit
	mov	cr0, ebx

	mov	cx, magic_no
	mov	ds, cx
	mov	es, cx
	mov	fs, cx
	mov	gs, cx
	
	jmp	0x08:flush

global idt_load	
idt_load:
	lidt	[app_idt_ram]
	ret

flush:
	ret

;*******************************************************************************
;			    	   GRUB Header
;*******************************************************************************

    	MULTIBOOT_PAGE_ALIGN	equ 1<<0
    	MULTIBOOT_MEMORY_INFO	equ 1<<1
        MULTIBOOT_HEADER_MAGIC	equ 0x1BADB002
	MULTIBOOT_HEADER_FLAGS	equ MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO
	MULTIBOOT_CHECKSUM	equ -(MULTIBOOT_HEADER_MAGIC + \
					MULTIBOOT_HEADER_FLAGS)
	EXTERN code, bss, end

align 4
        dd MULTIBOOT_HEADER_MAGIC
	dd MULTIBOOT_HEADER_FLAGS
	dd MULTIBOOT_CHECKSUM
	
;******************************/ End GRUB Header /******************************

SECTION .data
	cs_base		equ	0xFFFF0000
	ram_start	equ	0x400
	tss_index	equ	0xA
	linear_proto_lo	equ	0x0000FFFF
	linear_proto_hi equ	0x00CF9200
	pe_bit		equ	1b
	magic_no	equ	0x010

	extern app_gdt_ram
	extern app_idt_ram
	

SECTION .bss
	resb	8192

sys_stack: