head.s

⑴ 提供简单命令 A、通过串口加载程序到指定内存 B、将程序烧写到 NANDFLASH 指定位置 C、LCD 操作函数 I、画点 II、画线 III、画圆 IV、显示图像

	
	
	
	import nand_read
	import nand_init
	import Main
	area head,code,readonly
	entry

_start
	b	ResetHandle
	b	.
	b	.
	b	.
	b	.
	b	.
	b	.
	b	.
	

ResetHandle

;关看门狗	
	ldr r1, =0x53000000
	ldr r2, =0x0
	str r2, [r1]
;禁止所有中断
	ldr r1, =0x4A000008
	ldr r2, =0xFFFFFFFF
	str r2, [r1]
	ldr r1, =0x4A00001C
	ldr r2, =0xFFF
	str r2, [r1]
;初始化时钟系统
    ldr r1, =0x4C000000
	ldr r2, =0x00FFFFFF
	str r2, [r1]
	ldr r1, =0x4C000004
	ldr r2, =0xa1031
	str r2, [r1]
	ldr r1, =0x4C000014
	ldr r2, =0x3
	str r2, [r1]
;初始化IO
    ldr r1 ,=0x56000000
    ldr r2 ,=0x7fffff
    str r2,[r1]
;初始化内存控制器
	ldr r1, =0x48000000
	ldr r2, =0x22111110
	str r2, [r1]
	ldr r1, =0x48000004
	ldr r2, =0x00000700
	str r2, [r1]
	add r1, r1, #4
	str r2, [r1]
	add r1, r1,#4
	str r2,	[r1]
	add r1, r1,#4
	str r2, [r1]
	add r1, r1,#4
	str r2, [r1]
	add r1, r1,#4
	str r2, [r1]
	add r1, r1,#4
	ldr r2, =0x00018005
	str r2, [r1]
	add r1, r1, #4
	str r2, [r1]
	ldr r2, =0x008E0459
	add r1, r1, #4
	str r2, [r1]
	ldr r2, =0xb2
	add r1, r1, #4
	str r2, [r1]
	ldr r2,	=0x30
	add r1, r1, #4
	str r2, [r1]
	ldr r2,	=0x30
	add r1, r1, #4
	str r2, [r1]

;初始化串口
	ldr r1,	=0x50000000
	ldr r2,	=0x3
	str r2,	[r1]
	ldr	r1, =0x50000004
	ldr r2,	=0x245
	str r2,	[r1]
	ldr r1,	=0x50000008
	ldr r2,	=0x0
	str r2,	[r1]
	ldr r1,	=0x5000000C
	ldr r2,	=0x0
	str r2,	[r1]
	ldr r1,	=0x50000028
	ldr r2, =27
	str r2, [r1]
	ldr r1,	=0x56000070
	ldr r2, =0x2aaaaa
	str r2,	[r1]
	ldr r1, =0x56000078
	ldr r2,	=0x000007ff
	str r2,	[r1]

;点亮led
	ldr r1, =0x56000010
	ldr r2, =0x000005
	str r2, [r1]
	add r1,	r1,	#4
	ldr r2, =0x000 
	str r2,	[r1]
	add r1,	r1,	#4
	ldr r2,	=0x000
	str r2,	[r1]
;   ldr r1, =0x56000050
;	ldr r2,	=0x55aa
;	str r2,	[r1]
;	add r1, r1,	#4
;	ldr r2,	=0xff
;	str r2,	[r1]
;	add r1, r1,	#4
;	ldr r2, =0x00
;	str r2,	[r1]
;设置栈
	ldr sp,	=0x33900000
;初试化nandflash,拷贝自己到SDRAM
	ldr r1,	=0xf830
	ldr r2,	=0x4e000000
	str r1,[r2]
	bl nand_init
	ldr r0,	=0x0
	ldr r1,	=0x33000000
	ldr r2, =0x2000
	bl nand_read
	
;跳到SDRAM中
	ldr r0,	=on_the_ram
	add pc,	r0,	#0
	
on_the_ram

    
	bl Main	
	
	end