nand_read.c

ADS下关于2410的调试程序 启动部分由汇编完成 调试部分由c完成

/* 
 * vivi/s3c2410/nand_read.c: Simple NAND read functions for booting from NAND
 *
 * Copyright (C) 2002 MIZI Research, Inc.
 *
 * Author: Hwang, Chideok <[e-mail]>
 * Date  : $Date: 2002/08/14 10:26:47 $
 *
 * $Revision: 1.6 $
 * $Id: param.c,v 1.9 2002/07/11 06:17:20 nandy Exp 
 *
 * History
 *
 * 2002-05-xx: Hwang, Chideok <[e-mail]>
 *    - 瞪芭扼绊 抄叼俊霸 淋.
 *
 * 2002-05-xx: Chan Gyun Jeong <[e-mail]>
 *    - 抄叼狼 何殴阑 罐绊 力措肺 悼累窍档废 荐沥.
 *
 * 2002-08-10: Yong-iL Joh <[e-mail]>
 *    - SECTOR_SIZE啊 512牢 仇篮 促 佬档废 荐沥
 *
 */

#define __REGb(x)	(*(volatile unsigned char *)(x))
#define __REGi(x)	(*(volatile unsigned int *)(x))
#define NF_BASE		0x4e000000
#define NFCONF		__REGi(NF_BASE + 0x0)
#define NFCMD		__REGb(NF_BASE + 0x4)
#define NFADDR		__REGb(NF_BASE + 0x8)
#define NFDATA		__REGb(NF_BASE + 0xc)
#define NFSTAT		__REGb(NF_BASE + 0x10)

#define BUSY 1


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

/* low level nand read function */
int
nand_read_ll(unsigned char *buf, unsigned long start_addr, int size)
{
    int i, j;
    unsigned long begin_addr;
    
    if(size & NAND_BLOCK_MASK)
		size = (size/512 +1)*512;
	if (start_addr & NAND_BLOCK_MASK)
	{
		begin_addr = start_addr & 0xfffffe00;
	}
    //if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
   //     return -1;	/* invalid alignment */
   // }

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

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

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

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

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

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

    return 0;
}