这节我们实现nand的ecc，保存环境变量到nand flash 中。然后把我们之前的led灯烧写到nand flash 中，开机启动，在 tiny210.h 中定义宏 CONFIG_S5PV210_NAND_HWECC、CONFIG_SYS_NAND_ECCSIZE、CONFIG_SYS_NAND_ECCBYTES
CONFIG_SYS_NAND_ECCSIZE 定义了消息长度，即每多少字节进行 1 次 ECC 校验
CONFIG_SYS_NAND_ECCBYTES 定义为 13Byte，将 drivers/mtd/nand/s5pv210_nand.c 中的 CONFIG_S3C2410_NAND_HWECC 替换为CONFIG_S5PV210_NAND_HWECC,我们只进行 ECC 校验写，ECC 校验读使用三星提供的函数，我们必须按照三星手册规定的 ECC 校验码在
Spare Field 中的存储格式进行存储。
因此我们需要自定义 nand_ecclayout 结构体，这个结构体描述了如何存储 ECC 数据，同时将这个结构体赋值给 nand->ecc.layout
其他的代码请看源码:
/*
* (C) Copyright 2006 OpenMoko, Inc.
* Author: Harald Welte <[email protected]>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <nand.h>
#include <asm/arch/nand_reg.h>
#include <asm/io.h>
#define MP0_1CON (*(volatile u32 *)0xE02002E0)
#define MP0_3CON (*(volatile u32 *)0xE0200320)
#define MP0_6CON (*(volatile u32 *)0xE0200380)
/* modied by shl */
static void s5pv210_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *chip = mtd->priv;
struct s5pv210_nand *nand = (struct s5pv210_nand *)samsung_get_base_nand();
debug("hwcontrol(): 0x%02x 0x%02x\n", cmd, ctrl);
ulong IO_ADDR_W = (ulong)nand;
if (ctrl & NAND_CTRL_CHANGE) {
if (ctrl & NAND_CLE)
IO_ADDR_W = IO_ADDR_W | 0x8; /* Command Register */
else if (ctrl & NAND_ALE)
IO_ADDR_W = IO_ADDR_W | 0xC; /* Address Register */
chip->IO_ADDR_W = (void *)IO_ADDR_W;
if (ctrl & NAND_NCE) /* select */
writel(readl(&nand->nfcont) & ~(1 << 1), &nand->nfcont);
else /* deselect */
writel(readl(&nand->nfcont) | (1 << 1), &nand->nfcont);
}
if (cmd != NAND_CMD_NONE)
writeb(cmd, chip->IO_ADDR_W);
else
chip->IO_ADDR_W = &nand->nfdata;
}
static int s5pv210_dev_ready(struct mtd_info *mtd)
{
struct s5pv210_nand *nand = (struct s5pv210_nand *)samsung_get_base_nand();
debug("dev_ready\n");
return readl(&nand->nfstat) & 0x01;
}
#ifdef CONFIG_S5PV210_NAND_HWECC
void s5pv210_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
struct s5pv210_nand *nand = (struct s5pv210_nand *)samsung_get_base_nand();
debug("s5pv210_nand_enable_hwecc(%p, %d)\n", mtd, mode);
writel(readl(&nand->nfconf) | (0x3 << 23), &nand->nfconf);
if (mode == NAND_ECC_READ)
{
}
else if (mode == NAND_ECC_WRITE)
{
/* set 8/12/16bit Ecc direction to Encoding */
writel(readl(&nand->nfecccont) | (0x1 << 16), &nand->nfecccont);
/* clear 8/12/16bit ecc encode done */
writel(readl(&nand->nfeccstat) | (0x1 << 25), &nand->nfeccstat);
}
/* Initialize main area ECC decoder/encoder */
writel(readl(&nand->nfcont) | (0x1 << 5), &nand->nfcont);
/* The ECC message size(For 512-byte message, you should set 511)
* 8-bit ECC/512B */
writel((511 << 16) | 0x3, &nand->nfeccconf);
writel(readl(&nand->nfstat) | (0x1 << 4) | (0x1 << 5), &nand->nfstat);
/* Initialize main area ECC decoder/ encoder */
writel(readl(&nand->nfecccont) | (0x1 << 2), &nand->nfecccont);
/* Unlock Main area ECC */
writel(readl(&nand->nfcont) & ~(0x1 << 7), &nand->nfcont);
}
/* modied by shl */
static int s5pv210_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
u_char *ecc_code)
{
struct s5pv210_nand *nand = (struct s5pv210_nand *)samsung_get_base_nand();
u32 nfeccprgecc0 = 0, nfeccprgecc1 = 0, nfeccprgecc2 = 0, nfeccprgecc3 = 0;
/* Lock Main area ECC */
writel(readl(&nand->nfcont) | (1 << 7), &nand->nfcont);
/* 读取13 Byte的Ecc Code */
nfeccprgecc0 = readl(&nand->nfeccprgecc0);
nfeccprgecc1 = readl(&nand->nfeccprgecc1);
nfeccprgecc2 = readl(&nand->nfeccprgecc2);
nfeccprgecc3 = readl(&nand->nfeccprgecc3);
ecc_code[0] = nfeccprgecc0 & 0xff;
ecc_code[1] = (nfeccprgecc0 >> 8) & 0xff;
ecc_code[2] = (nfeccprgecc0 >> 16) & 0xff;
ecc_code[3] = (nfeccprgecc0 >> 24) & 0xff;
ecc_code[4] = nfeccprgecc1 & 0xff;
ecc_code[5] = (nfeccprgecc1 >> 8) & 0xff;
ecc_code[6] = (nfeccprgecc1 >> 16) & 0xff;
ecc_code[7] = (nfeccprgecc1 >> 24) & 0xff;
ecc_code[8] = nfeccprgecc2 & 0xff;
ecc_code[9] = (nfeccprgecc2 >> 8) & 0xff;
ecc_code[10] = (nfeccprgecc2 >> 16) & 0xff;
ecc_code[11] = (nfeccprgecc2 >> 24) & 0xff;
ecc_code[12] = nfeccprgecc3 & 0xff;
debug("s5pv210_nand_calculate_hwecc(%p,):\n"
"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n"
"0x%02x 0x%02x 0x%02x\n", mtd , ecc_code[0], ecc_code[1], ecc_code[2],
ecc_code[3], ecc_code[4], ecc_code[5], ecc_code[6], ecc_code[7],
ecc_code[8], ecc_code[9], ecc_code[10], ecc_code[11], ecc_code[12]);
return 0;
}
/* add by shl */
#define NF8_ReadPage_Adv(a,b,c) (((int(*)(u32, u32, u8*))(*((u32 *)0xD0037F90)))(a,b,c))
static int s5pv210_nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
uint8_t *buf, int oob_required, int page)
{
/* tiny210使用的NAND FLASH一个块64页 */
return NF8_ReadPage_Adv(page / 64, page % 64, buf);
}
static int s5pv210_nand_correct_data(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *calc_ecc)
{
if (read_ecc[0] == calc_ecc[0] &&
read_ecc[1] == calc_ecc[1] &&
read_ecc[2] == calc_ecc[2])
return 0;
printf("s5pv210_nand_correct_data: not implemented\n");
return -1;
}
#endif
/*
* add by shl
* nand_select_chip
* @mtd: MTD device structure
* @ctl: 0 to select, -1 for deselect
*
* Default select function for 1 chip devices.
*/
static void s5pv210_nand_select_chip(struct mtd_info *mtd, int ctl)
{
struct nand_chip *chip = mtd->priv;
switch (ctl) {
case -1: /* deselect the chip */
chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
break;
case 0: /* Select the chip */
chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
break;
default:
BUG();
}
}
/* add by shl */
static struct nand_ecclayout nand_oob_64 = {
.eccbytes = 52, /* 2048 / 512 * 13 */
.eccpos = { 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
62, 63},
/* 0和1用于保存坏块标记，12~63保存ecc，剩余2~11为free */
.oobfree = {
{.offset = 2,
.length = 10}
}
};
/* modied by shl */
int board_nand_init(struct nand_chip *nand)
{
u32 cfg = 0;
struct s5pv210_nand *nand_reg = (struct s5pv210_nand *)(struct s5pv210_nand *)samsung_get_base_nand();
debug("board_nand_init()\n");
/* initialize hardware */
/* HCLK_PSYS=133MHz(7.5ns) */
cfg = (0x1 << 23) | /* Disable 1-bit and 4-bit ECC */
/* 下面3个时间参数稍微比计算出的值大些（我这里依次加1），否则读写不稳定 */
(0x3 << 12) | /* 7.5ns * 2 > 12ns tALS tCLS */
(0x2 << 8) | /* (1+1) * 7.5ns > 12ns (tWP) */
(0x1 << 4) | /* (0+1) * 7.5 > 5ns (tCLH/tALH) */
(0x0 << 3) | /* SLC NAND Flash */
(0x0 << 2) | /* 2KBytes/Page */
(0x1 << 1); /* 5 address cycle */
writel(cfg, &nand_reg->nfconf);
writel((0x1 << 1) | (0x1 << 0), &nand_reg->nfcont);
/* Disable chip select and Enable NAND Flash Controller */
/* Config GPIO */
MP0_1CON &= ~(0xFFFF << 8);
MP0_1CON |= (0x3333 << 8);
MP0_3CON = 0x22222222;
MP0_6CON = 0x22222222;
/* initialize nand_chip data structure */
nand->IO_ADDR_R = (void *)&nand_reg->nfdata;
nand->IO_ADDR_W = (void *)&nand_reg->nfdata;
nand->select_chip = s5pv210_nand_select_chip;
/* read_buf and write_buf are default */
/* read_byte and write_byte are default */
/* hwcontrol always must be implemented */
nand->cmd_ctrl = s5pv210_hwcontrol;
nand->dev_ready = s5pv210_dev_ready;
#ifdef CONFIG_S5PV210_NAND_HWECC
nand->ecc.hwctl = s5pv210_nand_enable_hwecc;
nand->ecc.calculate = s5pv210_nand_calculate_ecc;
nand->ecc.correct = s5pv210_nand_correct_data;
nand->ecc.mode = NAND_ECC_HW;
nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
nand->ecc.strength = 1;
/* add by shl */
nand->ecc.layout = &nand_oob_64;
nand->ecc.read_page = s5pv210_nand_read_page_hwecc;
#else
nand->ecc.mode = NAND_ECC_SOFT;
#endif
#ifdef CONFIG_S3C2410_NAND_BBT
nand->bbt_options |= NAND_BBT_USE_FLASH;
#endif
debug("end of nand_init\n");
return 0;
}
重新编译，成功生成 u-boot.bin，将它烧写到 SD 卡的扇区 32，从 SD 卡启动开发板:
下面进行 NAND 启动试验，将之前的led程序烧写到 NAND，然后从 NAND 启动，可以看到 LED 全亮的效果。首先我们先编译
led.c，生成 led.bin，然后 添加 16B 的头信息生成 210.bin，然后将 210.bin 拷贝到 tftp 服务器目录。
然后使用最新的 u-boot 将 210.bin 烧写到 NAND 的第 0 页，然后从 NAND 启动
从 NAND 启动可以看到 4 个 LED 全亮。
时间： 2024-10-14 05:03:42