init.c

完全开发流程及源代码,基于s3c2410的嵌入式linux开发

#include "s3c2410.h"
#include "init.h"
#include "mmu.h"

/* SDRAM 13个寄存器的值 */ 
unsigned long  const	mem_cfg_val[]={	0x22111110,		//BWSCON
				0x00000700,		//BANKCON0
				0x00000700,		//BANKCON1
				0x00000700,		//BANKCON2
				0x00000700,		//BANKCON3	
				0x00000700,		//BANKCON4
				0x00000700,		//BANKCON5
				0x00018005,		//BANKCON6
				0x00018005,		//BANKCON7
				0x008e04f4,		//REFRESH,HCLK=12MHz:0x008e07a3,HCLK=100MHz:0x008e04f4
				0x000000b2,		//BANKSIZE
				0x00000030,		//MRSRB6
				0x00000030,		//MRSRB7
};


/*上电后，WATCH DOG默认是开着的，要把它关掉 */
void disable_watch_dog()
{
	WTCON	= 0;
}

/**************************************************************************   
* 设置控制SDRAM的13个寄存器
* 含有数组的代码，不是位置无关的，所以memsetup只能在连接位置执行
* 如果要使用位置无关代码，请使用memsetup_2
**************************************************************************/   
void memsetup()
{
	int 	i = 0;
	unsigned long *p = (unsigned long *)MEM_CTL_BASE;
	for(; i < 13; i++)
		p[i] = mem_cfg_val[i];
}


void memsetup_2()
{
	unsigned long *p = (unsigned long *)MEM_CTL_BASE;	
	p[0] = 0x22111110;		//BWSCON
	p[1] = 0x00000700;		//BANKCON0
	p[2] = 0x00000700;		//BANKCON1
	p[3] = 0x00000700;		//BANKCON2
	p[4] = 0x00000700;		//BANKCON3	
	p[5] = 0x00000700;		//BANKCON4
	p[6] = 0x00000700;		//BANKCON5
	p[7] = 0x00018005;		//BANKCON6
	p[8] = 0x00018005;		//BANKCON7
	p[9] = 0x008e04f4;		//REFRESH,HCLK=12MHz:0x008e07a3,HCLK=100MHz:0x008e04f4						
	p[10] = 0x000000b2;		//BANKSIZE
	p[11] = 0x00000030;		//MRSRB6
	p[12] = 0x00000030;		//MRSRB7
}


/* 在第一次实用NAND Flash前，复位一下NAND Flash */
void reset_nand()
{
	int i=0;
	NFCONF &= ~0x800;
	for(; i<10; i++);
	NFCMD = 0xff;	//reset command
	wait_idle();
}

/* 初始化NAND Flash */
void init_nand()
{
	NFCONF = 0xf830;
	reset_nand();
}


/*************************************************************************
*	以下读NAND Flash的代码来自mizi公司的bootloader vivi
*************************************************************************/
#define BUSY 1
inline void wait_idle(void) {
	int i;

	while(!(NFSTAT & BUSY))
		for(i=0; i<10; i++);
}

#define NAND_SECTOR_SIZE	512
#define NAND_BLOCK_MASK		(NAND_SECTOR_SIZE - 1)

/* low level nand read function */
void nand_read_ll(unsigned char *buf, unsigned long start_addr, int size)
{
	int i, j;

	if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
		return ;	/* invalid alignment */
	}

	/* chip Enable */
	NFCONF &= ~0x800;
	for(i=0; i<10; i++);

	for(i=start_addr; i < (start_addr + size);) {
		/* READ0 */
		NFCMD = 0;

		/* Write Address */
		NFADDR = i & 0xff;
		NFADDR = (i >> 9) & 0xff;
		NFADDR = (i >> 17) & 0xff;
		NFADDR = (i >> 25) & 0xff;

		wait_idle();

		for(j=0; j < NAND_SECTOR_SIZE; j++, i++) {
			*buf = (NFDATA & 0xff);
			buf++;
		}
	}

	/* chip Disable */
	NFCONF |= 0x800;	/* chip disable */

	return ;
}


/***************************************************************************
* 中断向量起始虚拟地址为0xffff0000，段是1M对齐的，所以0xfff00000虚拟地址对应
* 0x33f00000(VECTORS_PHY_BASE),而虚拟地址0xffff0000则对应0x33f00000+0xf0000
***************************************************************************/
void copy_vectors_from_nand_to_sdram()
{
	nand_read_ll((unsigned char*)(VECTORS_PHY_BASE+0xf0000), 0x0, 512);	
}

void copy_process_from_nand_to_sdram()
{
	nand_read_ll((unsigned char*)PROCESS0_BASE, 0x0, 0x100000-16*1024);//进程0空间为1M-16K页表
//	nand_read_ll((unsigned char*)(0x30100000), 15*1024, 1024);
//	nand_read_ll((unsigned char*)PROCESS2_BASE, 0x8000, 1024);	
}


#define EINT1		(2<<(1*2))
#define EINT2		(2<<(2*2))
#define EINT3		(2<<(3*2))
#define EINT7		(2<<(7*2))

void init_irq( )
{
	GPFCON |= EINT1 | EINT2 | EINT3 | EINT7;
	GPFUP	 |= (1<<1) | (1<<2) | (1<<3) | (1<<7);
	
	EINTMASK &= (~0x80);	//EINT7使能
	INTMSK	&= (~0x1e);	//EINT1-3、EINT7使能
	
	INTMSK &= (~(1<<10));	//INT_TIMER0使能
	
	PRIORITY &= (~0x03);	//设定优先级
}




#define MPLL_200MHz	(0x5c << 12)|(0x04 << 4)|(0x00)
/***************************************************************************
* 对于MPLLCON寄存器，[19:12]为MDIV，[9:4]为PDIV，[1:0]为SDIV
* 有如下计算公式：
*	MPLL(FCLK) = (m * Fin)/(p * 2^s)
*	其中: m = MDIV + 8, p = PDIV + 2
* 对于本开发板，Fin = 12MHz,MPLLCON设为MPLL_200MHz，可以计算出FCLK=200MHz
***************************************************************************/
void clock_init()
{
	LOCKTIME = 0x00ffffff;
	CLKDIVN  = 0x03;	/*FCLK:HCLK:PCLK=1:2:4, HDIVN1=0,HDIVN=1,PDIVN=1 */

	/*If HDIVN = 1,the CPU bus mode has to be changed from the fast bus mode
	  to the asynchronous bus mod using following instructions.*/
__asm__(
	"mrc	p15, 0, r1, c1, c0, 0\n"		/* read ctrl register   */ 
	"orr	r1, r1, #0xc0000000\n"		/* Asynchronous         */
	"mcr	p15, 0, r1, c1, c0, 0\n"		/* write ctrl register  */
	);

	 MPLLCON = MPLL_200MHz;	/*现在，FCLK=200MHz,HCLK=100MHz,PCLK=50MHz*/
	 
}


/*************************************************************************
* Timer input clock Frequency = PCLK / {prescaler value+1} / {divider value}
* {prescaler value} = 0~255
* {divider value} = 2, 4, 8, 16
* 本实验的Timer0的时钟频率=50MHz/(49+1)/(16)=62500Hz
* 设置Timer0 10ms触发一次中断：TCNTB0[15:0]=625
*************************************************************************/
void Timer0_init()
{
	TCFG0 = 49;		//Prescaler0 = 49	  	 
	TCFG1 = 0x03;	//Select MUX input for PWM Timer0:divider=16
//	TCNTB0 = 625;	//10ms触发一次中断
	TCNTB0 = 62500;	//1s触发一次中断,用于调试	
	TCON |=  (1<<1);	//Timer 0 manual update
	TCON = 0x09;	/*Timer 0 auto reload on
			  Timer 0 output inverter off
			  清"Timer 0 manual update"
			  Timer 0 start */
}