我们已知uboot启动的第二阶段是从lib_arm/board.c中的start_armboot函数启动
1、第336-339行
#if defined(CONFIG_CMD_NAND)
puts ("NAND: ");
nand_init(); /* go init the NAND */
#endif
所以在include/configs/100ask24x0.h中添加宏#define CONFIG_CMD_NAND
2、nand_init()会调用driver/mtd/nand/nand.c中的nand_init()函数(在顶层的Makefile中被编译到库函数中)
,同时CONFIG_SYS_MAX_NAND_DEVICE也需要在100ask24x0.h中定义:#define CONFIG_SYS_MAX_NAND_DEVICE 1
3、init_init()函数会调用同文件中的nand_init_chip函数,nand_init_chip函数则会调用board_nand_init函数,通过编译会发现board_nand_init函数根本就没定义(没有编译到库文件中),此时需要将board_nand_init编译到库函数中
4、知道了我们的目的,我们基于driver/mtd/nand/s3c2410.c进行修改,首先需要将s3c2410.c编译到库函数中,则在同级目录下的Makefile中添加:COBJS-y += s3c2410_nand.o,同时COBJS-$(CONFIG_NAND_S3C2440) += s3c2410_nand.o,后者就跟着修改了,我在100ask24x0.h中定义了宏CONFIG_NAND_S3C2440,而注释掉了CONFIG_NAND_S3C2410,我就跟着改了;
然后在s3c2410_nand.c中增加2440的配置信息。具体代码如下:
#include <common.h>
#include <nand.h>
//#include <asm/arch/s3c24x0.h>
#include <asm/arch/s3c24x0_cpu.h>
#include <asm/arch/s3c2410.h>
#include <asm/io.h>
#define NF_BASE 0x4e000000
#if defined(CONFIG_S3C2410)
#define S3C2410_NFCONF_EN (1<<15)
#define S3C2410_NFCONF_512BYTE (1<<14)
#define S3C2410_NFCONF_4STEP (1<<13)
#define S3C2410_NFCONF_INITECC (1<<12)
#define S3C2410_NFCONF_nFCE (1<<11)
#define S3C2410_NFCONF_TACLS(x) ((x)<<8)
#define S3C2410_NFCONF_TWRPH0(x) ((x)<<4)
#define S3C2410_NFCONF_TWRPH1(x) ((x)<<0)
#define S3C2410_ADDR_NALE 4
#define S3C2410_ADDR_NCLE 8
#endif
#if defined(CONFIG_S3C2440)
#define S3C2410_NFCONT_EN (1<<0)
#define S3C2410_NFCONT_INITECC (1<<4)
#define S3C2410_NFCONT_nFCE (1<<1)
#define S3C2410_NFCONT_MAINECCLOCK (1<<5)
#define S3C2410_NFCONF_TACLS(x) ((x)<<12)
#define S3C2410_NFCONF_TWRPH0(x) ((x)<<8)
#define S3C2410_NFCONF_TWRPH1(x) ((x)<<4)
#define S3C2410_ADDR_NALE 0x08
#define S3C2410_ADDR_NCLE 0x0c
#endif
ulong IO_ADDR_W = NF_BASE;
#ifdef CONFIG_NAND_SPL
/* in the early stage of NAND flash booting, printf() is not available */
#define printf(fmt, args...)
static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
int i;
struct nand_chip *this = mtd->priv;
for (i = 0; i < len; i++)
buf[i] = readb(this->IO_ADDR_R);
}
#endif
static void s3c2410_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
// struct nand_chip *chip = mtd->priv;
#if defined(CONFIG_S3C2410)
struct s3c2410_nand *nand = s3c2410_get_base_nand();
#endif
#if defined(CONFIG_S3C2440)
//struct S3C2440_NAND *nand = s3c2440_get_base_nand();0x4E000000
struct S3C2440_NAND *nand = (struct S3C2440_NAND *)0x4E000000;
#endif
debugX(1, "hwcontrol(): 0x%02x 0x%02x\n", cmd, ctrl);
if (ctrl & NAND_CTRL_CHANGE) {
IO_ADDR_W = (ulong)nand;
if (!(ctrl & NAND_CLE))
IO_ADDR_W |= S3C2410_ADDR_NCLE;
if (!(ctrl & NAND_ALE))
IO_ADDR_W |= S3C2410_ADDR_NALE;
// chip->IO_ADDR_W = (void *)IO_ADDR_W;
#if defined(CONFIG_S3C2410)
if (ctrl & NAND_NCE)
writel(readl(&nand->NFCONF) & ~S3C2410_NFCONF_nFCE,
&nand->NFCONF);
else
writel(readl(&nand->NFCONF) | S3C2410_NFCONF_nFCE,
&nand->NFCONF);
}
#endif
#if defined(CONFIG_S3C2440)
if (ctrl & NAND_NCE)
writel(readl(&nand->NFCONT) & ~S3C2410_NFCONT_nFCE,
&nand->NFCONT);
else
writel(readl(&nand->NFCONT) | S3C2410_NFCONT_nFCE,
&nand->NFCONT);
}
#endif
if (cmd != NAND_CMD_NONE)
writeb(cmd, (void *)IO_ADDR_W);
}
static int s3c2410_dev_ready(struct mtd_info *mtd)
{
#if defined(CONFIG_S3C2410)
struct s3c2410_nand *nand = s3c2410_get_base_nand();
#endif
#if defined(CONFIG_S3C2440)
//struct S3C2440_NAND *nand = s3c2440_get_base_nand();
struct S3C2440_NAND *nand = (struct S3C2440_NAND *)0x4E000000;
#endif
debugX(1, "dev_ready\n");
return readl(&nand->NFSTAT) & 0x01;
}
#ifdef CONFIG_S3C2410_NAND_HWECC
void s3c2410_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
#if defined(CONFIG_S3C2410)
struct s3c2410_nand *nand = s3c2410_get_base_nand();
#endif
#if defined(CONFIG_S3C2440)
struct S3C2440_NAND *nand = s3c2440_get_base_nand();
#endif
debugX(1, "s3c2410_nand_enable_hwecc(%p, %d)\n", mtd, mode);
#if defined(CONFIG_S3C2410)
writel(readl(&nand->NFCONF) | S3C2410_NFCONF_INITECC, &nand->NFCONF);
#endif
#if defined(CONFIG_S3C2440)
writel(readl(&nand->NFCONT) | S3C2410_NFCONT_INITECC, &nand->NFCONT);
#endif
}
static int s3c2410_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
u_char *ecc_code)
{
struct s3c2410_nand *nand = s3c2410_get_base_nand();
ecc_code[0] = readb(&nand->NFECC);
ecc_code[1] = readb(&nand->NFECC + 1);
ecc_code[2] = readb(&nand->NFECC + 2);
debugX(1, "s3c2410_nand_calculate_hwecc(%p,): 0x%02x 0x%02x 0x%02x\n",
mtd , ecc_code[0], ecc_code[1], ecc_code[2]);
return 0;
}
static int s3c2410_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("s3c2410_nand_correct_data: not implemented\n");
return -1;
}
#endif
int board_nand_init(struct nand_chip *nand)
{
u_int32_t cfg;
u_int8_t tacls, twrph0, twrph1;
struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
#if defined(CONFIG_S3C2410)
struct s3c2410_nand *nand_reg = s3c2410_get_base_nand();
#endif
#if defined(CONFIG_S3C2440)
//struct S3C2440_NAND *nand_reg = s3c2440_get_base_nand();
struct S3C2440_NAND *nand_reg = (struct S3C2440_NAND *)0x4E000000;
#endif
debugX(1, "board_nand_init()\n");
writel(readl(&clk_power->CLKCON) | (1 << 4), &clk_power->CLKCON);
#if defined(CONFIG_S3C2410)
/* initialize hardware */
twrph0 = 3;
twrph1 = 0;
tacls = 0;
cfg = S3C2410_NFCONF_EN;
cfg |= S3C2410_NFCONF_TACLS(tacls - 1);
cfg |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
cfg |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
writel(cfg, &nand_reg->NFCONF);
/* initialize nand_chip data structure */
nand->IO_ADDR_R = nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;
#endif
#if defined(CONFIG_S3C2440)
/*
twrph0 = 4;
twrph1 = 2;
tacls = 0;*/
twrph0 = 2;
twrph1 = 1;
tacls = 2;
cfg = 0;
cfg |= S3C2410_NFCONF_TACLS(tacls);
cfg |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
cfg |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
writel(cfg, &nand_reg->NFCONF);
cfg = (0<<13)|(0<<12)|(0<<10)|(0<<9)|(0<<8)|(0<<6)|(0<<5)|(1<<4)|(0<<1)|(1<<0);
writel(cfg, &nand_reg->NFCONT);
/* initialize nand_chip data structure */
nand->IO_ADDR_R = nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;
#endif
nand->select_chip = NULL;
/* read_buf and write_buf are default */
/* read_byte and write_byte are default */
#ifdef CONFIG_NAND_SPL
nand->read_buf = nand_read_buf;
#endif
/* hwcontrol always must be implemented */
nand->cmd_ctrl = s3c2410_hwcontrol;
nand->dev_ready = s3c2410_dev_ready;
#ifdef CONFIG_S3C2410_NAND_HWECC
nand->ecc.hwctl = s3c2410_nand_enable_hwecc;
nand->ecc.calculate = s3c2410_nand_calculate_ecc;
nand->ecc.correct = s3c2410_nand_correct_data;
nand->ecc.mode = NAND_ECC_HW;
nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
#else
nand->ecc.mode = NAND_ECC_SOFT;
#endif
#ifdef CONFIG_S3C2410_NAND_BBT
nand->options = NAND_USE_FLASH_BBT;
#else
nand->options = 0;
#endif
debugX(1, "end of nand_init\n");
return 0;
}
然后执行make 100ask24x0_config;make;解决所有出现的报错
之后编译通过之后:
#1将u-boot.bin烧录nor flash
#2从nor启动,进入u-boot,输入?,会发现nand的一些信息
#3在u-boot下执行 nand erase 会擦除整个nand成功
#4将测试文件led.bin烧写到nand中,方法:通过tftp 0x30000000 led.bin烧写led.bin到0x30000000的内存地址中;然后执行
nand write 0x30000000 0 0x3000将内存为0x30000000大小为0x3000的程序段烧写到nand偏移地址为0处。
#选择从nand启动,led灯亮起,说明烧写成功