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nand_boot.c 4.65 KiB
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  • /*
     * (C) Copyright 2006
     * Stefan Roese, DENX Software Engineering, sr@denx.de.
     *
     * This program is free software; you can redistribute it and/or
     * modify it under the terms of the GNU General Public License as
     * published by the Free Software Foundation; either version 2 of
     * the License, or (at your option) any later version.
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with this program; if not, write to the Free Software
     * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
     * MA 02111-1307 USA
     */
    
    #include <common.h>
    #include <nand.h>
    
    #define CFG_NAND_READ_DELAY \
    	{ volatile int dummy; int i; for (i=0; i<10000; i++) dummy = i; }
    
    extern void board_nand_init(struct nand_chip *nand);
    extern void ndfc_hwcontrol(struct mtd_info *mtdinfo, int cmd);
    extern void ndfc_write_byte(struct mtd_info *mtdinfo, u_char byte);
    extern u_char ndfc_read_byte(struct mtd_info *mtdinfo);
    extern int ndfc_dev_ready(struct mtd_info *mtdinfo);
    extern int jump_to_ram(ulong delta);
    extern int jump_to_uboot(ulong addr);
    
    static int nand_is_bad_block(struct mtd_info *mtd, int block)
    {
            struct nand_chip *this = mtd->priv;
    	int page_addr = block * CFG_NAND_PAGE_COUNT;
    
    	/* Begin command latch cycle */
    	this->hwcontrol(mtd, NAND_CTL_SETCLE);
    	this->write_byte(mtd, NAND_CMD_READOOB);
    	/* Set ALE and clear CLE to start address cycle */
    	this->hwcontrol(mtd, NAND_CTL_CLRCLE);
    	this->hwcontrol(mtd, NAND_CTL_SETALE);
    	/* Column address */
    	this->write_byte(mtd, CFG_NAND_BAD_BLOCK_POS);			/* A[7:0] */
    	this->write_byte(mtd, (uchar)(page_addr & 0xff));		/* A[16:9] */
    	this->write_byte(mtd, (uchar)((page_addr >> 8) & 0xff));	/* A[24:17] */
    #ifdef CFG_NAND_4_ADDR_CYCLE
    	/* One more address cycle for devices > 32MiB */
    	this->write_byte(mtd, (uchar)((page_addr >> 16) & 0x0f));	/* A[xx:25] */
    #endif
    	/* Latch in address */
    	this->hwcontrol(mtd, NAND_CTL_CLRALE);
    
    	/*
    	 * Wait a while for the data to be ready
    	 */
    	if (this->dev_ready)
    		this->dev_ready(mtd);
    	else
    		CFG_NAND_READ_DELAY;
    
    	/*
    	 * Read on byte
    	 */
    	if (this->read_byte(mtd) != 0xff)
    		return 1;
    
    	return 0;
    }
    
    static int nand_read_page(struct mtd_info *mtd, int block, int page, uchar *dst)
    {
            struct nand_chip *this = mtd->priv;
    	int page_addr = page + block * CFG_NAND_PAGE_COUNT;
    	int i;
    
    	/* Begin command latch cycle */
    	this->hwcontrol(mtd, NAND_CTL_SETCLE);
    	this->write_byte(mtd, NAND_CMD_READ0);
    	/* Set ALE and clear CLE to start address cycle */
    	this->hwcontrol(mtd, NAND_CTL_CLRCLE);
    	this->hwcontrol(mtd, NAND_CTL_SETALE);
    	/* Column address */
    	this->write_byte(mtd, 0);					/* A[7:0] */
    	this->write_byte(mtd, (uchar)(page_addr & 0xff));		/* A[16:9] */
    	this->write_byte(mtd, (uchar)((page_addr >> 8) & 0xff));	/* A[24:17] */
    #ifdef CFG_NAND_4_ADDR_CYCLE
    	/* One more address cycle for devices > 32MiB */
    	this->write_byte(mtd, (uchar)((page_addr >> 16) & 0x0f));	/* A[xx:25] */
    #endif
    	/* Latch in address */
    	this->hwcontrol(mtd, NAND_CTL_CLRALE);
    
    	/*
    	 * Wait a while for the data to be ready
    	 */
    	if (this->dev_ready)
    		this->dev_ready(mtd);
    	else
    		CFG_NAND_READ_DELAY;
    
    	/*
    	 * Read page into buffer
    	 */
    	for (i=0; i<CFG_NAND_PAGE_SIZE; i++)
    		*dst++ = this->read_byte(mtd);
    
    	return 0;
    }
    
    static int nand_load(struct mtd_info *mtd, int offs, int uboot_size, uchar *dst)
    {
    	int block;
    	int blockcopy_count;
    	int page;
    
    	/*
    	 * offs has to be aligned to a block address!
    	 */
    	block = offs / CFG_NAND_BLOCK_SIZE;
    	blockcopy_count = 0;
    
    	while (blockcopy_count < (uboot_size / CFG_NAND_BLOCK_SIZE)) {
    		if (!nand_is_bad_block(mtd, block)) {
    			/*
    			 * Skip bad blocks
    			 */
    			for (page = 0; page < CFG_NAND_PAGE_COUNT; page++) {
    				nand_read_page(mtd, block, page, dst);
    				dst += CFG_NAND_PAGE_SIZE;
    			}
    
    			blockcopy_count++;
    		}
    
    		block++;
    	}
    
    	return 0;
    }
    
    void nand_boot(void)
    {
    	ulong mem_size;
    	struct nand_chip nand_chip;
    	nand_info_t nand_info;
    	int ret;
    	void (*uboot)(void);
    
    	/*
    	 * Init sdram, so we have access to memory
    	 */
    	mem_size = initdram(0);
    
    	/*
    	 * Init board specific nand support
    	 */
    	nand_info.priv = &nand_chip;
    	nand_chip.IO_ADDR_R = nand_chip.IO_ADDR_W = (void  __iomem *)CFG_NAND_BASE;
    	nand_chip.dev_ready = NULL;	/* preset to NULL */
    	board_nand_init(&nand_chip);
    
    	/*
    	 * Load U-Boot image from NAND into RAM
    	 */
    	ret = nand_load(&nand_info, CFG_NAND_U_BOOT_OFFS,
    			CFG_NAND_U_BOOT_SIZE,
    			(uchar *)CFG_NAND_U_BOOT_DST);
    
    	/*
    	 * Jump to U-Boot image
    	 */
    	uboot = (void (*)(void))CFG_NAND_U_BOOT_START;
    	(*uboot)();
    }