nand.c

如果想自制一个自己的BOOTLOADER

#include "def.h"
#include "addr.h"
#include "lib.h"

#define	EnNandFlash()	(rNFCONF |= 0x8000)
#define	DsNandFlash()	(rNFCONF &= ~0x8000)
#define	InitEcc()		(rNFCONF |= 0x1000)
#define	NoEcc()			(rNFCONF &= ~0x1000)
#define	NFChipEn()		(rNFCONF &= ~0x800)
#define	NFChipDs()		(rNFCONF |= 0x800)

#define	WrNFCmd(cmd)	(rNFCMD = (cmd))
#define	WrNFAddr(addr)	(rNFADDR = (addr))
#define	WrNFDat(dat)	(rNFDATA = (dat))
#define	RdNFDat()		(rNFDATA)
#define	RdNFStat()		(rNFSTAT)
#define	NFIsBusy()		(!(rNFSTAT&1))
#define	NFIsReady()		(rNFSTAT&1)



#define	READCMD0	0
#define	READCMD1	1
#define	READCMD2	0x50
#define	ERASECMD0	0x60
#define	ERASECMD1	0xd0
#define	PROGCMD0	0x80
#define	PROGCMD1	0x10
#define	QUERYCMD	0x70
#define	RdIDCMD		0x90

static U16 NandAddr;


static void InitNandCfg(void)
{
	//enable nand flash control, initilize ecc, chip disable,
	rNFCONF = (1<<15)|(1<<12)|(1<<11)|(7<<8)|(7<<4)|(7);	
}

#ifdef	WIAT_BUSY_HARD
#define	WaitNFBusy()	while(NFIsBusy())
#else
static U32 WaitNFBusy(void)	// R/B 未接好?
{
	U8 stat;
	
	WrNFCmd(QUERYCMD);
	do {
		stat = RdNFDat();
		//printf("%x\n", stat);
	}while(!(stat&0x40));
	WrNFCmd(READCMD0);
	return stat&1;
}
#endif

static U32 ReadChipId(void)
{
	U32 id;
	
	NFChipEn();	
	WrNFCmd(RdIDCMD);
	WrNFAddr(0);
	while(NFIsBusy());	
	id  = RdNFDat()<<8;
	id |= RdNFDat();		
	NFChipDs();		
	
	return id;
}

static U16 ReadStatus(void)
{
	U16 stat;
	
	NFChipEn();	
	WrNFCmd(QUERYCMD);		
	stat = RdNFDat();	
	NFChipDs();
	
	return stat;
}


static void ReadPage(U32 addr, U8 *buf)
{
	U16 i;
	
	NFChipEn();
	WrNFCmd(READCMD0);
	WrNFAddr(0);
	WrNFAddr(addr);
	WrNFAddr(addr>>8);
	if(NandAddr)
		WrNFAddr(addr>>16);
	InitEcc();
	WaitNFBusy();
	for(i=0; i<512; i++)
		buf[i] = RdNFDat();
	NFChipDs();
}



static void MarkBadBlk(U32 addr)
{
	addr &= ~0x1f;
	
	NFChipEn();
	
	WrNFCmd(READCMD2);	//point to area c
	
	WrNFCmd(PROGCMD0);
	WrNFAddr(4);		//mark offset 4,5,6,7
	WrNFAddr(addr);
	WrNFAddr(addr>>8);
	if(NandAddr)
		WrNFAddr(addr>>16);
	WrNFDat(0);			//mark with 0
	WrNFDat(0);
	WrNFDat(0);			//mark with 0
	WrNFDat(0);
	WrNFCmd(PROGCMD1);
	WaitNFBusy();		//needn't check return status
	
	WrNFCmd(READCMD0);	//point to area a
		
	NFChipDs();
}

static int CheckBadBlk(U32 addr)
{
	U8 dat;
	
	addr &= ~0x1f;
	
	NFChipEn();
	
	WrNFCmd(READCMD2);	//point to area c
	WrNFAddr(5);		//mark offset 4,5,6,7
	WrNFAddr(addr);
	WrNFAddr(addr>>8);
	if(NandAddr)
		WrNFAddr(addr>>16);
	WaitNFBusy();
	dat = RdNFDat();
	
	WrNFCmd(READCMD0);	//point to area a
	
	NFChipDs();

	return (dat!=0xff);
}

/************************************************************/
struct Partition{
	U32 offset;
	U32 size;
	char *name;
};

static struct Partition NandPart[] = {
	{0, 		 0x00040000, "boot"},		//256K
	{0x00040000, 0x001c0000, "kernel"},
	{0x00200000, 0x00600000, "rootfs"},		//6M
	{0x00800000, 0x00800000, "ext-fs1"},	//8M
	{0x01000000, 0x01000000, "ext-fs2"},	//16M
	{0x02000000, 0x02000000, "ext-fs3"},	//32M
	{0,			 0         , 0}
};

static U32 StartPage, BlockCnt;
extern U32 downloadAddress; 
extern U32 downloadFileSize;



#define LINUX_PAGE_SHIFT	12
#define LINUX_PAGE_SIZE		(1<<LINUX_PAGE_SHIFT)
#define COMMAND_LINE_SIZE 	1024

struct param_struct {
    union {
	struct {
	    unsigned long page_size;			/*  0 */
	    unsigned long nr_pages;				/*  4 */
	    unsigned long ramdisk_size;			/*  8 */
	    unsigned long flags;				/* 12 */
#define FLAG_READONLY	1
#define FLAG_RDLOAD		4
#define FLAG_RDPROMPT	8
	    unsigned long rootdev;				/* 16 */
	    unsigned long video_num_cols;		/* 20 */
	    unsigned long video_num_rows;		/* 24 */
	    unsigned long video_x;				/* 28 */
	    unsigned long video_y;				/* 32 */
	    unsigned long memc_control_reg;		/* 36 */
	    unsigned char sounddefault;			/* 40 */
	    unsigned char adfsdrives;			/* 41 */
	    unsigned char bytes_per_char_h;		/* 42 */
	    unsigned char bytes_per_char_v;		/* 43 */
	    unsigned long pages_in_bank[4];		/* 44 */
	    unsigned long pages_in_vram;		/* 60 */
	    unsigned long initrd_start;			/* 64 */
	    unsigned long initrd_size;			/* 68 */
	    unsigned long rd_start;				/* 72 */
	    unsigned long system_rev;			/* 76 */
	    unsigned long system_serial_low;	/* 80 */
	    unsigned long system_serial_high;	/* 84 */
	    unsigned long mem_fclk_21285;       /* 88 */
	} s;
	char unused[256];
    } u1;
    union {
	char paths[8][128];
	struct {
	    unsigned long magic;
	    char n[1024 - sizeof(unsigned long)];
	} s;
    } u2;
    char commandline[COMMAND_LINE_SIZE];
};

extern char boot_params[];
extern void  call_linux(U32 a0, U32 a1, U32 a2);

static void LoadRun(int part_sel)
{
	U32 i, ram_addr, buf = 0x30200000;
	struct param_struct *params = (struct param_struct *)0x30000100;
	int size;

	char *linux_params = "root=/dev/mtdblock2 load_ramdisk=0 init=/linuxrc console=ttyS0 mem=64M devfs=mount";

	puts("The LoadRun function is called!\n");
	StartPage = NandPart[part_sel].offset>>9;
	size = NandPart[part_sel].size;
	ram_addr = buf;	
	
	for(i=0; size>0; ) {
		if(!(i&0x1f)) {
			if(CheckBadBlk(i+StartPage)) {
				printf("Skipped bad block at 0x%x\n", i+StartPage);
				i += 32;
				size -= 32<<9;
				continue;
			}
		}
		ReadPage((i+StartPage), (U8 *)ram_addr);
		i++;
		size -= 512;
		ram_addr += 512;
	}
	DsNandFlash();

	for(i=0; i<(sizeof(struct param_struct)>>2); i++)
		((U32 *)params)[i] = 0;
	params->u1.s.page_size = LINUX_PAGE_SIZE;
	params->u1.s.nr_pages = (0x04000000 >> LINUX_PAGE_SHIFT);
	for(i=0; linux_params[i]; i++)
		params->commandline[i] = linux_params[i];
	
	puts("Set boot params = ");
	puts(linux_params);
	putch('\n');
	call_linux(0, 193, buf);
}


static void InitNandFlash(void)
{	
	U32 i;
	
	InitNandCfg();
	i = ReadChipId();
	printf("Read chip id = %x\n", i);	
	if((i==0x9873)||(i==0xec75))	
		NandAddr = 0;
	else if(i==0xec76)
	{	
		NandAddr = 1;
	}
	else {	
		puts("Chip id error!!!\n");
		return;
	}
	printf("Nand flash status = %x\n", ReadStatus());
}



void NandLoadRun(void)
{

	InitNandFlash();
	LoadRun(1);
}