日志
U-Boot 1.3.1源码阅读之NAND FLASH接口
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U－Boot 1.3.1是U－Boot目前的最新版本，和以前的版本相比，增加了对大页面NAND FLASH 的支持。早期版本基本上只能支持到512字节的页面大小，而现在市面上大多是2K字节页面大小的NAND FLASH，这样的FLASH容量大，价格低，性价比很高，很受电子设计工程师的青睐。
看源代码board目录下，有很多板子的配置。可以使用源代码阅读工具，搜索一下，可以看到其中有很多板子的目录下都有一个nand.c文件，文件中有一些nand flash必须的借口函数。下面逐一介绍。
board_nand_init函数
在这个函数可以定义NAND FLASH 命令／数据的地址，典型的可以看board/sc3/sc3nand.c文件： sc3_io_base = (void *) CFG_NAND_BASE;
/* Set address of NAND IO lines (Using Linear Data Access Region) */
nand->IO_ADDR_R = (void __iomem *) sc3_io_base;
nand->IO_ADDR_W = (void __iomem *) sc3_io_base;
还有一些接口也是必须的，如设置用户自定义的一些接口函数，比较典型的可以看board/prodrive/pdnp3/nand.c文件：
int board_nand_init(struct nand_chip *nand)
{
pdnb3_ndfc = (struct pdnb3_ndfc_regs *)CFG_NAND_BASE;
nand->eccmode = NAND_ECC_SOFT;
/* Set address of NAND IO lines (Using Linear Data Access Region) */
nand->IO_ADDR_R = (void __iomem *) ((ulong) pdnb3_ndfc + 0x4);
nand->IO_ADDR_W = (void __iomem *) ((ulong) pdnb3_ndfc + 0x4);
/* Reference hardware control function */
nand->hwcontrol = pdnb3_nand_hwcontrol;
/* Set command delay time */
nand->hwcontrol = pdnb3_nand_hwcontrol;
nand->write_byte = pdnb3_nand_write_byte;
nand->read_byte = pdnb3_nand_read_byte;
nand->write_buf = pdnb3_nand_write_buf;
nand->read_buf = pdnb3_nand_read_buf;
nand->verify_buf = pdnb3_nand_verify_buf;
nand->dev_ready = pdnb3_nand_dev_ready;
return 0;
}
如果在这里定义了这些接口函数，则必须实现，用于替换u-boot的默认函数实现。
nand_chip数据结构
其实，这里面最重要的是nand_chip数据结构，请看文件include/linux/mtd/nand.h：
/**
* struct nand_chip - NAND Private Flash Chip Data
* @IO_ADDR_R: [BOARDSPECIFIC] address to read the 8 I/O lines of the flash device
* @IO_ADDR_W: [BOARDSPECIFIC] address to write the 8 I/O lines of the flash device
* @read_byte: [REPLACEABLE] read one byte from the chip
* @write_byte: [REPLACEABLE] write one byte to the chip
* @read_word: [REPLACEABLE] read one word from the chip
* @write_word: [REPLACEABLE] write one word to the chip
* @write_buf: [REPLACEABLE] write data from the buffer to the chip
* @read_buf: [REPLACEABLE] read data from the chip into the buffer
* @verify_buf: [REPLACEABLE] verify buffer contents against the chip data
* @select_chip: [REPLACEABLE] select chip nr
* @block_bad: [REPLACEABLE] check, if the block is bad
* @block_markbad: [REPLACEABLE] mark the block bad
* @hwcontrol: [BOARDSPECIFIC] hardwarespecific function for accesing control-lines
* @dev_ready: [BOARDSPECIFIC] hardwarespecific function for accesing device ready/busy line
* If set to NULL no access to ready/busy is available and the ready/busy information
* is read from the chip status register
* @cmdfunc: [REPLACEABLE] hardwarespecific function for writing commands to the chip
* @waitfunc: [REPLACEABLE] hardwarespecific function for wait on ready
* @calculate_ecc: [REPLACEABLE] function for ecc calculation or readback from ecc hardware
* @correct_data: [REPLACEABLE] function for ecc correction, matching to ecc generator (sw/hw)
* @enable_hwecc: [BOARDSPECIFIC] function to enable (reset) hardware ecc generator. Must only
* be provided if a hardware ECC is available
* @erase_cmd: [INTERN] erase command write function, selectable due to AND support
* @scan_bbt: [REPLACEABLE] function to scan bad block table
* @eccmode: [BOARDSPECIFIC] mode of ecc, see defines
* @eccsize: [INTERN] databytes used per ecc-calculation
* @eccbytes: [INTERN] number of ecc bytes per ecc-calculation step
* @eccsteps: [INTERN] number of ecc calculation steps per page
* @chip_delay: [BOARDSPECIFIC] chip dependent delay for transfering data from array to read regs (tR)
* @chip_lock: [INTERN] spinlock used to protect access to this structure and the chip
* @wq: [INTERN] wait queue to sleep on if a NAND operation is in progress
* @state: [INTERN] the current state of the NAND device
* @page_shift: [INTERN] number of address bits in a page (column address bits)
* @phys_erase_shift: [INTERN] number of address bits in a physical eraseblock
* @bbt_erase_shift: [INTERN] number of address bits in a bbt entry
* @chip_shift: [INTERN] number of address bits in one chip
* @data_buf: [INTERN] internal buffer for one page + oob
* @oob_buf: [INTERN] oob buffer for one eraseblock
* @oobdirty: [INTERN] indicates that oob_buf must be reinitialized
* @data_poi: [INTERN] pointer to a data buffer
* @options: [BOARDSPECIFIC] various chip options. They can partly be set to inform. nand_scan about
* special functionality. See the defines for further explanation
* @badblockpos: [INTERN] position of the bad block marker in the oob area
* @numchips: [INTERN] number of physical chips
* @chipsize: [INTERN] the size of one chip for multichip arrays
* @pagemask: [INTERN] page number mask = number of (pages / chip) - 1
* @pagebuf: [INTERN] holds the pagenumber which is currently in data_buf
* @autooob: [REPLACEABLE] the default (auto)placement scheme
* @bbt: [INTERN] bad block table pointer
* @bbt_td: [REPLACEABLE] bad block table descriptor for flash lookup
* @bbt_md: [REPLACEABLE] bad block table mirror descriptor
* @badblock_pattern: [REPLACEABLE] bad block scan pattern used for initial bad block scan
* @controller: [OPTIONAL] a pointer to a hardware controller structure which is shared among multiple independend devices
* @priv: [OPTIONAL] pointer to private chip date
*/
struct nand_chip {
void __iomem *IO_ADDR_R;
void __iomem *IO_ADDR_W;
u_char (*read_byte)(struct mtd_info *mtd);
void (*write_byte)(struct mtd_info *mtd, u_char byte);
u16 (*read_word)(struct mtd_info *mtd);
void (*write_word)(struct mtd_info *mtd, u16 word);
void (*write_buf)(struct mtd_info *mtd, const u_char *buf, int len);
void (*read_buf)(struct mtd_info *mtd, u_char *buf, int len);
int (*verify_buf)(struct mtd_info *mtd, const u_char *buf, int len);
void (*select_chip)(struct mtd_info *mtd, int chip);
int (*block_bad)(struct mtd_info *mtd, loff_t ofs, int getchip);
int (*block_markbad)(struct mtd_info *mtd, loff_t ofs);
void (*hwcontrol)(struct mtd_info *mtd, int cmd);
int (*dev_ready)(struct mtd_info *mtd);
void (*cmdfunc)(struct mtd_info *mtd, unsigned command, int column, int page_addr);
int (*waitfunc)(struct mtd_info *mtd, struct nand_chip *this, int state);
int (*calculate_ecc)(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code);
int (*correct_data)(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc);
void (*enable_hwecc)(struct mtd_info *mtd, int mode);
void (*erase_cmd)(struct mtd_info *mtd, int page);
int (*scan_bbt)(struct mtd_info *mtd);
int eccmode;
int eccsize;
int eccbytes;
int eccsteps;
int chip_delay;
#if 0
spinlock_t chip_lock;
wait_queue_head_t wq;
nand_state_t state;
#endif
int page_shift;
int phys_erase_shift;
int bbt_erase_shift;
int chip_shift;
u_char *data_buf;
u_char *oob_buf;
int oobdirty;
u_char *data_poi;
unsigned int options;
int badblockpos;
int numchips;
unsigned long chipsize;
int pagemask;
int pagebuf;
struct nand_oobinfo *autooob;
uint8_t *bbt;
struct nand_bbt_descr *bbt_td;
struct nand_bbt_descr *bbt_md;
struct nand_bbt_descr *badblock_pattern;
struct nand_hw_control *controller;
void *priv;
};
这个数据结构的注视非常明了，指出了那些函数可以被替换，可被替换的函数，用户可以根据自己的需求实现，一般在上面所讲的nand.c中实现。当然，在其他地方实现也可以，U-Boot源代码中也有这样的例子。
nand_base.c文件
nand_chip数据结构定义的函数，U-Boot的默认实现在drivers/mtd/nand/nand_base.c文件中。可以仔细看看源码。如果要进行替换，这些函数有一定的参考价值。
如果要为nand_chip数据结构增加某些接口函数或者某些成员，可以修改这两个文件。
nand Flash和nand_legacy
nand目录下的文件是能够支持2K大页面的NAND FLASH的实现，而nand_legacy目录下的文件只能支持到512字节的页面，在使用的时候需要加以区分。
原文来自：http://blog.chinaunix.net/u1/51797/showart_455357.html
移植U－Boot.1.3.1到S3C244和S3C2410
首先，U-Boot1.3.1还没有支持s3c2440，移植仍是用2410的文件稍作修改而成的。2440和2410的区别在我移植1.2.0的文章中已经写了，这里不再赘述。
对于1.3.1和1.2.0的差别，我初看了一下，（对于ARM920T内核）应该是增加了对ATMEL公司的AT91RM9200系列处理器的支持。至于S3C24X0系列的芯片，原理上并没有什么大的变化。
一、在U-Boot中建立自己的开发板类型，并测试编译。
我为开发板取名叫: tekkaman2440
0 在工作目录下解压U－Boot。
[tekkamanninja@ARM9-Host working]$ tar -xjvf u-boot-1.3.1.tar.bz2
1 进入U-Boot目录，修改Makefile（我在fedora 8 下，比较喜欢使用KWrite）
[tekkamanninja@ARM9-Host working]$ cd u-boot-1.3.1
[tekkamanninja@ARM9-Host u-boot-1.3.1]$ kwrite Makefile
#为tekkaman2440建立编译项
sbc2410x_config: unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t sbc2410x NULL s3c24x0
tekkaman2440_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t tekkaman2440 tekkaman s3c24x0
各项的意思如下:
arm: CPU的架构(ARCH)
arm920t: CPU的类型(CPU)，其对应于cpu/arm920t子目录。
tekkaman2440: 开发板的型号(BOARD)，对应于board/tekkaman/tekkaman2440目录。
tekkaman: 开发者/或经销商(vender)。
s3c24x0: 片上系统(SOC)。
同时在“ifndef CROSS_COMPILE ”之前加上自己交叉编译器的路径，比如我使用crosstool-0.43制作的基于2.6.24内核和gcc-4.1.1-glibc-2.3.2的ARM9TDMI交叉编译器，则：
CROSS_COMPILE=/home/tekkamanninja/working/gcc4.1.1/gcc-4.1.1-glibc-2.3.2/arm-9tdmi-linux-gnu/bin/arm-9tdmi-linux-gnu-
2 在/board子目录中建立自己的开发板tekkaman2440目录
由于我在上一步板子的开发者/或经销商(vender)中填了 tekkaman ，所以开发板tekkaman2440目录一定要建在/board子目录中的tekkaman目录下 ，否则编译会出错。
[tekkamanninja@ARM9-Host u-boot-1.3.1]$ cd board
[tekkamanninja@ARM9-Host board]$ mkdir tekkaman tekkaman/tekkaman2440
[tekkamanninja@ARM9-Host board]$ cp -arf sbc2410x/* tekkaman/tekkaman2440/
[tekkamanninja@ARM9-Host board]$ cd tekkaman/tekkaman2440/
[tekkamanninja@ARM9-Host tekkaman2440]$ mv sbc2410x.c tekkaman2440.c
还要记得修改自己的开发板tekkaman2440目录下的Makefile文件，不然编译时会出错：
[tekkamanninja@ARM9-Host tekkaman2440]$ kwrite Makefile
COBJS := tekkaman2440.o flash.o
3 在include/configs/中建立配置头文件
[tekkamanninja@ARM9-Host tekkaman2440]$ cd ../../..
[tekkamanninja@ARM9-Host u-boot-1.3.1]$ cp include/configs/sbc2410x.h include/configs/tekkaman2440.h
4 测试编译能否成功
1、配置
[tekkamanninja@ARM9-Host u-boot-1.3.1]$ make tekkaman2440_config
Configuring for tekkaman2440 board...
可能出现的问题:
(1) 如果出现：
$ make tekkaman2440_config
Makefile:1927: *** 遗漏分隔符 。 停止。
请在U－boot的根目录下的Makefile的
@$(MKCONFIG) $(@:_config=) arm arm920t tekkaman2440 tekkaman)
前加上“Tab”键
2、测试编译
[tekkamanninja@ARM9-Host u-boot-1.3.1]$make
测试通过后进行下一步
二、修改U－Boot中的文件，以同时匹配2440和2410。
1 修改/cpu/arm920t/start.S
#include <config.h>
#include <version.h>
#if defined(CONFIG_AT91RM9200DK)
#include <status_led.h> /*这是针对AT91RM9200DK开发板的。对于SCB2440V4也有4个LED指示灯，我用来指示程序用行的进度。*/
#endif
......
/*
* the actual start code
*/
start_code:
/*
* set the cpu to SVC32 mode
*/
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0xd3
msr cpsr,r0
#if defined(CONFIG_AT91RM9200DK)
bl coloured_LED_init
bl red_LED_on
#endif
(0)修改寄存器地址定义
#if defined(CONFIG_S3C2400) || defined(CONFIG_S3C2410)|| defined(CONFIG_S3C2440)
/* turn off the watchdog */
#if defined(CONFIG_S3C2400)
#define pWTCON 0x15300000
#define INTMSK 0x14400008 /* Interupt-Controller base addresses */
#define CLKDIVN 0x14800014 /* clock divisor register */
#else
#define pWTCON 0x53000000
#define INTMSK 0x4A000008 /* Interupt-Controller base addresses */
#define INTSUBMSK 0x4A00001C
#define CLKDIVN 0x4C000014 /* clock divisor register */
#endif
#define CLK_CTL_BASE 0x4C000000 /* tekkaman */
#define MDIV_405 0x7f << 12 /* tekkaman */
#define PSDIV_405 0x21 /* tekkaman */
#define MDIV_200 0xa1 << 12 /* tekkaman */
#define PSDIV_200 0x31 /* tekkaman */
......
(1)修改中断禁止部分
#if defined(CONFIG_S3C2410)
ldr r1, =0x7ff /*根据2410芯片手册，INTSUBMSK有11位可用，
vivi也是0x7ff，U－Boot一直没改过来。*/
ldr r0, =INTSUBMSK
str r1, [r0]
#endif
#if defined(CONFIG_S3C2440)
ldr r1, =0x7fff /*根据2440芯片手册，INTSUBMSK有15位可用*/
ldr r0, =INTSUBMSK
str r1, [r0]
#endif
(2)修改时钟设置（2440的主频为405MHz。）
# if defined(CONFIG_S3C2440)
/* FCLK:HCLK:PCLK = 1:4:8 */
ldr r0, =CLKDIVN
mov r1, #5
str r1, [r0]
mrc p15, 0, r1, c1, c0, 0 /*read ctrl register tekkaman*/
orr r1, r1, #0xc0000000 /*Asynchronous tekkaman*/
mcr p15, 0, r1, c1, c0, 0 /*write ctrl register tekkaman*/
/*now, CPU clock is 405.00 Mhz tekkaman*/
mov r1, #CLK_CTL_BASE /* tekkaman*/
mov r2, #MDIV_405 /* mpll_405mhz tekkaman*/
add r2, r2, #PSDIV_405 /* mpll_405mhz tekkaman*/
str r2, [r1, #0x04] /* MPLLCON tekkaman */
#else
/* FCLK:HCLK:PCLK = 1:2:4 */
/* default FCLK is 12 MHz ! 在这里U－Boot有一个错误：以为默认时钟为120MHz。其实如果没有添加以下设置FCLK的语句，芯片内部的PLL是无效的，即FCLK为12MHz。S3C24x0的芯片手册说得很明白。我一开始没有注意到这一点，是 CalmArrow提醒了我并和我讨论过，他也做过实验证实了这点。在这里对CalmArrow表示感谢和敬意！*/
ldr r0, =CLKDIVN
mov r1, #3
str r1, [r0]
mrc p15, 0, r1, c1, c0, 0 /*read ctrl register tekkaman*/
orr r1, r1, #0xc0000000 /*Asynchronous tekkaman*/
mcr p15, 0, r1, c1, c0, 0 /*write ctrl register tekkaman*/
/*now, CPU clock is 202.8 Mhz tekkaman*/
mov r1, #CLK_CTL_BASE /* tekkaman*/
mov r2, #MDIV_200 /* mpll_200mhz tekkaman*/
add r2, r2, #PSDIV_200 /* mpll_200mhz tekkaman*/
str r2, [r1, #0x04]
# endif
#endif /* CONFIG_S3C2400 || CONFIG_S3C2410|| CONFIG_S3C2440 */
红色部分是我添加的，利用vivi的代码。
(3)将从Flash启动改成从NAND Flash启动。
在以下U－Boot的重定向语句段：
#ifdef CONFIG_AT91RM9200
#ifndef CONFIG_SKIP_RELOCATE_UBOOT
relocate: /* relocate U-Boot to RAM */
adr r0, _start /* r0 <- current position of code */
ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
cmp r0, r1 /* don't reloc during debug */
beq stack_setup
ldr r2, _armboot_start
ldr r3, _bss_start
sub r2, r3, r2 /* r2 <- size of armboot */
add r2, r0, r2 /* r2 <- source end address*/
copy_loop:
ldmia {r3-r10} /* copy from source address [r0] */
stmia {r3-r10} /* copy to target address [r1] */
cmp r0, r2 /* until source end addreee [r2] */
ble copy_loop
#endif /* CONFIG_SKIP_RELOCATE_UBOOT */
#endif
的后面添加上：
#ifdef CONFIG_S3C2440_NAND_BOOT
@ reset NAND
mov r1, #NAND_CTL_BASE
ldr r2, =( (7<<12)|(7<<8)|(7<<4)|(0<<0) )
str r2, [r1, #oNFCONF]
ldr r2, [r1, #oNFCONF]
ldr r2, =( (1<<4)|(0<<1)|(1<<0) ) @ Active low CE Control
str r2, [r1, #oNFCONT]
ldr r2, [r1, #oNFCONT]
ldr r2, =(0x6) @ RnB Clear
str r2, [r1, #oNFSTAT]
ldr r2, [r1, #oNFSTAT]
mov r2, #0xff @ RESET command
strb r2, [r1, #oNFCMD]
mov r3, #0 @ wait
nand1:
add r3, r3, #0x1
cmp r3, #0xa
blt nand1
nand2:
ldr r2, [r1, #oNFSTAT] @ wait ready
tst r2, #0x4
beq nand2
ldr r2, [r1, #oNFCONT]
orr r2, r2, #0x2 @ Flash Memory Chip Disable
str r2, [r1, #oNFCONT]
@ get read to call C functions (for nand_read())
ldr sp, DW_STACK_START @ setup stack pointer
mov fp, #0 @ no previous frame, so fp=0
@ copy U-Boot to RAM
ldr r0, =TEXT_BASE
mov r1, #0x0
mov r2, #0x30000
bl nand_read_ll
tst r0, #0x0
beq ok_nand_read
bad_nand_read:
loop2: b loop2 @ infinite loop
ok_nand_read:
@ verify
mov r0, #0
ldr r1, =TEXT_BASE
mov r2, #0x400 @ 4 bytes * 1024 = 4K-bytes
go_next:
ldr r3, [r0], #4
ldr r4, [r1], #4
teq r3, r4
bne notmatch
subs r2, r2, #4
beq stack_setup
bne go_next
notmatch:
loop3: b loop3 @ infinite loop
#endif @ CONFIG_S3C2440_NAND_BOOT
#ifdef CONFIG_S3C2410_NAND_BOOT
@ reset NAND
mov r1, #NAND_CTL_BASE
ldr r2, =0xf830 @ initial value
str r2, [r1, #oNFCONF]
ldr r2, [r1, #oNFCONF]
bic r2, r2, #0x800 @ enable chip
str r2, [r1, #oNFCONF]
mov r2, #0xff @ RESET command
strb r2, [r1, #oNFCMD]
mov r3, #0 @ wait
nand1:
add r3, r3, #0x1
cmp r3, #0xa
blt nand1
nand2:
ldr r2, [r1, #oNFSTAT] @ wait ready
tst r2, #0x1
beq nand2
ldr r2, [r1, #oNFCONF]
orr r2, r2, #0x800 @ disable chip
str r2, [r1, #oNFCONF]
@ get read to call C functions (for nand_read())
ldr sp, DW_STACK_START @ setup stack pointer
mov fp, #0 @ no previous frame, so fp=0
@ copy U-Boot to RAM
ldr r0, =TEXT_BASE
mov r1, #0x0
mov r2, #0x30000
bl nand_read_ll
tst r0, #0x0
beq ok_nand_read
bad_nand_read:
loop2: b loop2 @ infinite loop
ok_nand_read:
@ verify
mov r0, #0
ldr r1, =TEXT_BASE
mov r2, #0x400 @ 4 bytes * 1024 = 4K-bytes
go_next:
ldr r3, [r0], #4
ldr r4, [r1], #4
teq r3, r4
bne notmatch
subs r2, r2, #4
beq stack_setup
bne go_next
notmatch:
loop3: b loop3 @ infinite loop
#endif @ CONFIG_S3C2410_NAND_BOOT
在“ldr pc, _start_armboot”之前加入：
# if defined(CONFIG_tekkaman2440_LED)
@ LED1 on u-boot stage 1 is
mov r1, #GPIO_CTL_BASE
add r1, r1, #oGPIO_B
ldr r2,=0x155aa
str r2, [r1, #oGPIO_CON]
mov r2, #0xff
str r2, [r1, #oGPIO_UP]
mov r2, #0x1c0
str r2, [r1, #oGPIO_DAT]
#endif
修改目的：如果看到只有LED1亮了，说明U－Boot的第一阶段已完成！(针对友善之臂SBC2440V4，不是这块开发板的，必须修改或不添加)
在 “ _start_armboot: .word start_armboot ” 后加入：
.align 2
DW_STACK_START: .word STACK_BASE+STACK_SIZE-4
2 在board/tekkaman/tekkaman2440加入NAND Flash读函数文件，拷贝vivi中的nand_read.c文件到此文件夹即可：
#include <config.h>
#define __REGb(x) (*(volatile unsigned char *)(x))
#define __REGi(x) (*(volatile unsigned int *)(x))
#define NF_BASE 0x4e000000
# if defined(CONFIG_S3C2440)
#define NFCONF __REGi(NF_BASE + 0x0)
#define NFCONT __REGi(NF_BASE + 0x4)
#define NFCMD __REGb(NF_BASE + 0x8)
#define NFADDR __REGb(NF_BASE + 0xC)
#define NFDATA __REGb(NF_BASE + 0x10)
#define NFSTAT __REGb(NF_BASE + 0x20)
//#define GPDAT __REGi(GPIO_CTL_BASE+oGPIO_F+oGPIO_DAT)
#define NAND_CHIP_ENABLE (NFCONT &= ~(1<<1))
#define NAND_CHIP_DISABLE (NFCONT |= (1<<1))
#define NAND_CLEAR_RB (NFSTAT |= (1<<2))
#define NAND_DETECT_RB { while(! (NFSTAT&(1<<2)) );}
#define BUSY 4
inline void wait_idle(void) {
while(!(NFSTAT & BUSY));
NFSTAT |= BUSY;
}
#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;
if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
return -1; /* invalid alignment */
}
NAND_CHIP_ENABLE;
for(i=start_addr; i < (start_addr + size);) {
/* READ0 */
NAND_CLEAR_RB;
NFCMD = 0;
/* Write Address */
NFADDR = i & 0xff;
NFADDR = (i >> 9) & 0xff;
NFADDR = (i >> 17) & 0xff;
NFADDR = (i >> 25) & 0xff;
NAND_DETECT_RB;
for(j=0; j < NAND_SECTOR_SIZE; j++, i++) {
*buf = (NFDATA & 0xff);
buf++;
}
}
NAND_CHIP_DISABLE;
return 0;
}
# endif
# if defined(CONFIG_S3C2410)
#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
inline void wait_idle(void) {
int i;
while(!(NFSTAT & BUSY))
for(i=0; i<10; i++);
}
/* low level nand read function */
int
nand_read_ll(unsigned char *buf, unsigned long start_addr, int size)
{
int i, j;
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=start_addr; i < (start_addr + size);) {
/* READ0 */
NFCMD = 0;
/* Write Address */
NFADDR = i & 0xff;
NFADDR = (i >> 9) & 0xff;
NFADDR = (i >> 17) & 0xff;
NFADDR = (i >> 25) & 0xff;
wait_idle();
for(j=0; j < NAND_SECTOR_SIZE; j++, i++) {
*buf = (NFDATA & 0xff);
buf++;
}
}
/* chip Disable */
NFCONF |= 0x800; /* chip disable */
return 0;
}
# endif
3 修改board/tekkaman/tekkaman2440/Makefile文件
......
OBJS := tekkaman2440.o nand_read.o flash.o
......
4 修改include/configs/tekkaman2440.h文件，添加如下内容：
......
/*
* Nandflash Boot
*/
#define STACK_BASE 0x33f00000
#define STACK_SIZE 0x8000
//#define UBOOT_RAM_BASE 0x33f80000
/* NAND Flash Controller */
#define NAND_CTL_BASE 0x4E000000
#define bINT_CTL(Nb) __REG(INT_CTL_BASE + (Nb))
/* Offset */
#define oNFCONF 0x00
# if defined(CONFIG_S3C2440)
#define CONFIG_S3C2440_NAND_BOOT 1
/* Offset */
#define oNFCONT 0x04
#define oNFCMD 0x08
#define oNFADDR 0x0c
#define oNFDATA 0x10
#define oNFSTAT 0x20
#define oNFECC 0x2c
#define rNFCONF (*(volatile unsigned int *)0x4e000000)
#define rNFCONT (*(volatile unsigned int *)0x4e000004)
#define rNFCMD (*(volatile unsigned char *)0x4e000008)
#define rNFADDR (*(volatile unsigned char *)0x4e00000c)
#define rNFDATA (*(volatile unsigned char *)0x4e000010)
#define rNFSTAT (*(volatile unsigned int *)0x4e000020)
#define rNFECC (*(volatile unsigned int *)0x4e00002c)
# if defined(CONFIG_tekkaman2440_LED)
/* GPIO */
#define GPIO_CTL_BASE 0x56000000
#define oGPIO_B 0x10
#define oGPIO_CON 0x0 /* R/W, Configures the pins of the port */
#define oGPIO_DAT 0x4 /* R/W, Data register for port */
#define oGPIO_UP 0x8 /* R/W, Pull-up disable register */
#endif
# if defined(CONFIG_S3C2410)
#define CONFIG_S3C2410_NAND_BOOT 1
/* Offset */
#define oNFCONF 0x00
#define oNFCMD 0x04
#define oNFADDR 0x08
#define oNFDATA 0x0c
#define oNFSTAT 0x10
#define oNFECC 0x14
#define rNFCONF (*(volatile unsigned int *)0x4e000000)
#define rNFCMD (*(volatile unsigned char *)0x4e000004)
#define rNFADDR (*(volatile unsigned char *)0x4e000008)
#define rNFDATA (*(volatile unsigned char *)0x4e00000c)
#define rNFSTAT (*(volatile unsigned int *)0x4e000010)
#define rNFECC (*(volatile unsigned int *)0x4e000014)
#define rNFECC0 (*(volatile unsigned char *)0x4e000014)
#define rNFECC1 (*(volatile unsigned char *)0x4e000015)
#define rNFECC2 (*(volatile unsigned char *)0x4e000016)
#endif
/*JFFS2 Support */
#undef CONFIG_JFFS2_CMDLINE
#define CONFIG_JFFS2_NAND 1
#define CONFIG_JFFS2_DEV "nand0"
#define CONFIG_JFFS2_PART_SIZE 0x4c0000
#define CONFIG_JFFS2_PART_OFFSET 0x40000
/*JFFS2 Support */
/* USB Support 080218 */
#define CONFIG_USB_OHCI
#define CONFIG_USB_STORAGE
#define CONFIG_USB_KEYBOARD
#define CONFIG_DOS_PARTITION
#define CFG_DEVICE_DEREGISTER
#define CONFIG_SUPPORT_VFAT
#define LITTLEENDIAN
/* USB Support 080218 */
#endif /* __CONFIG_H */
5 修改board/tekkaman/tekkaman2440/lowlevel_init.S文件
依照开发板的内存区的配置情况, 修改board/tekkaman/tekkaman2440/lowlevel_init.S文件，我利用友善之臂提供的vivi源码里的信息做了如下更改:
......
#define B1_BWSCON (DW16)
#if defined(CONFIG_DRIVER_NE2000)
#define B2_BWSCON (DW16 + UBLB)
#else
#define B2_BWSCON (DW16)
#endif
#define B3_BWSCON (DW16 + WAIT + UBLB)
#define B4_BWSCON (DW16)
#define B5_BWSCON (DW16)
#define B6_BWSCON (DW32)
#define B7_BWSCON (DW32)
......
#if defined(CONFIG_DRIVER_NE2000)
#define B2_Tacs 0x3 /* 4clk tekkaman*/
#define B2_Tcos 0x3 /* 4clk tekkaman*/
#define B2_Tacc 0x7 /* 14clk */
#define B2_Tcoh 0x3 /* 4clk tekkaman*/
#define B2_Tah 0x3 /* 4clk tekkaman*/
#define B2_Tacp 0x3 /* 6clk tekkaman*/
#define B2_PMC 0x0 /* normal */
#else
#define B2_Tacs 0x0
#define B2_Tcos 0x0
#define B2_Tacc 0x7
#define B2_Tcoh 0x0
#define B2_Tah 0x0
#define B2_Tacp 0x0
#define B2_PMC 0x0
#endif
……
/* REFRESH parameter */
#define REFEN 0x1 /* Refresh enable */
#define TREFMD 0x0 /* CBR(CAS before RAS)/Auto refresh */
#define Trc 0x3 /* 7clk */
#define Tchr 0x2 /* 3clk */
# if defined(CONFIG_S3C2440)
#define Trp 0x2 /* 4clk */
#define REFCNT 1012
#else
#define Trp 0x0 /* 2clk */
#define REFCNT 0x0459
#endif
6 修改/board/tekkaman/tekkaman2440/tekkaman2440.c
修改其对GPIO和PLL的配置(请参阅开发板的硬件说明和芯片手册)：
......
#define FCLK_SPEED 1
#if FCLK_SPEED==0 /* Fout = 203MHz, Fin = 12MHz for Audio */
#define M_MDIV 0xC3
#define M_PDIV 0x4
#define M_SDIV 0x1
#elif FCLK_SPEED==1
#if defined(CONFIG_S3C2410)
/* Fout = 202.8MHz */
#define M_MDIV 0xA1
#define M_PDIV 0x3
#define M_SDIV 0x1
#endif
#if defined(CONFIG_S3C2440)
/* Fout = 405MHz */
#define M_MDIV 0x7f
#define M_PDIV 0x2
#define M_SDIV 0x1
#endif
#define USB_CLOCK 1
#if USB_CLOCK==0
#define U_M_MDIV 0xA1
#define U_M_PDIV 0x3
#define U_M_SDIV 0x1
#elif USB_CLOCK==1
#if defined(CONFIG_S3C2410)
#define U_M_MDIV 0x48
#define U_M_PDIV 0x3
#endif
#if defined(CONFIG_S3C2440)
#define U_M_MDIV 0x38
#define U_M_PDIV 0x2
#endif
#define U_M_SDIV 0x2
#endif
......
/* set up the I/O ports */
gpio->GPACON = 0x007FFFFF;
# if defined(CONFIG_tekkaman2440_LED)
gpio->GPBCON = 0x00055556;
#else
gpio->GPBCON = 0x00044556;
#endif
......
#if defined(CONFIG_S3C2410)
/* arch number of SMDK2410-Board */
gd->bd->bi_arch_number = MACH_TYPE_SMDK2410;
#endif
#if defined(CONFIG_S3C2440)
/* arch number of S3C2440 -Board */
gd->bd->bi_arch_number = MACH_TYPE_S3C2440 ;
#endif
/* adress of boot parameters */
gd->bd->bi_boot_params = 0x30000100;
icache_enable();
dcache_enable();
# if defined(CONFIG_tekkaman2440_LED)
gpio->GPBDAT = 0x180; //tekkamanninja
//int board_init (void)设置完成后，LED1和LED2会亮起！
#endif
return 0;
}
7 为了实现NAND Flash的读写，再次修改/include/configs/tekkaman2440.h
(请格外注意：如果编译时报错，在Linux下用KWrite等有高亮显示的文本编辑器看看文件的注释是不是为注释应有的颜色（KWrite中为灰色），如果不是,则将注释删除。因为#define后面的注释被认为是程序的一部分。建议注释和#define分行写)
......
/*
* High Level Configuration Options
* (easy to change)
*/
#define CONFIG_ARM920T 1 /* This is an ARM920T Core */
//#define CONFIG_S3C2410 1 /* in a SAMSUNG S3C2410 SoC */
//#define CONFIG_SBC2410X 1 /* on a friendly-arm SBC-2410X Board */
#define CONFIG_S3C2440 1 /* in a SAMSUNG S3C2440 SoC */
#define CONFIG_tekkaman2440 1 /* on a SAMSUNG tekkaman2440 Board */
#define CONFIG_tekkaman2440_LED 1 /* Use the LED on Board */
......
/*
* Command line configuration.
*/
#include <config_cmd_default.h>
#define CONFIG_CMD_ASKENV
#define CONFIG_CMD_CACHE
#define CONFIG_CMD_DATE
#define CONFIG_CMD_DHCP
#define CONFIG_CMD_ELF
#define CONFIG_CMD_PING
#define CONFIG_CMD_NAND
#define CONFIG_CMD_REGINFO
#define CONFIG_CMD_JFFS2
/* JFFS2 Support 080218 */
#define CONFIG_CMD_USB
/* USB Support 080218 */
#define CONFIG_CMD_FAT
/* FAT support 080218 */
......
#define CFG_LONGHELP
/* undef to save memory */
#define CFG_PROMPT "[Tekkaman2440]#"
/*Monitor Command Prompt */
#define CFG_CBSIZE 256
/* Console I/O Buffer Size */
......
#define CFG_LOAD_ADDR 0x30008000
/* default load address */
......
/* timeout values are in ticks */
#define CFG_FLASH_ERASE_TOUT (5*CFG_HZ) /* Timeout for Flash Erase */
#define CFG_FLASH_WRITE_TOUT (5*CFG_HZ) /* Timeout for Flash Write */
#define CFG_ENV_IS_IN_NAND 1
#define CFG_ENV_OFFSET 0X30000
#define CFG_NAND_LEGACY
//#define CFG_ENV_IS_IN_FLASH 1
#define CFG_ENV_SIZE 0x10000 /* Total Size of Environment Sector */
/*----------------------------------------------------------------------
* NAND flash settings
*/
#if defined(CONFIG_CMD_NAND)
#define CFG_NAND_BASE 0x4E000000
/* NandFlash控制器在SFR区起始寄存器地址 */
#define CFG_MAX_NAND_DEVICE 1
/* 支持的最在Nand Flash数据 */
#define SECTORSIZE 512
/* 1页的大小 */
#define NAND_SECTOR_SIZE SECTORSIZE
#define NAND_BLOCK_MASK 511
/* 页掩码 */
#define ADDR_COLUMN 1
/* 一个字节的Column地址 */
#define ADDR_PAGE 3
/* 3字节的页块地址!!!!!*/
#define ADDR_COLUMN_PAGE 4
/* 总共4字节的页块地址!!!!! */
#define NAND_ChipID_UNKNOWN 0x00
/* 未知芯片的ID号 */
#define NAND_MAX_FLOORS 1
#define NAND_MAX_CHIPS 1
/* Nand Flash命令层底层接口函数 */
#define WRITE_NAND_ADDRESS(d, adr) {rNFADDR = d;}
#define WRITE_NAND(d, adr) {rNFDATA = d;}
#define READ_NAND(adr) (rNFDATA)
#define NAND_WAIT_READY(nand) {while(!(rNFSTAT&(1<<0)));}
#define WRITE_NAND_COMMAND(d, adr) {rNFCMD = d;}
#define WRITE_NAND_COMMANDW(d, adr) NF_CmdW(d)
# if defined(CONFIG_S3C2440)
#define NAND_DISABLE_CE(nand) {rNFCONT |= (1<<1);}
#define NAND_ENABLE_CE(nand) {rNFCONT &= ~(1<<1);}
#endif
# if defined(CONFIG_S3C2410)
#define NAND_DISABLE_CE(nand) {rNFCONF |= (1<<11);}
#define NAND_ENABLE_CE(nand) {rNFCONF &= ~(1<<11);}
#endif
/* the following functions are NOP's because S3C24X0 handles this in hardware */
#define NAND_CTL_CLRALE(nandptr)
#define NAND_CTL_SETALE(nandptr)
#define NAND_CTL_CLRCLE(nandptr)
#define NAND_CTL_SETCLE(nandptr)
/* 允许Nand Flash写校验 */
#define CONFIG_MTD_NAND_VERIFY_WRITE 1
......
#endif /* __CONFIG_H */
8、在个文件中添加“CONFIG_S3C2440”，使得原来s3c2410的代码可以编译进来。
（1）/include/common.h文件的第474行：
#if defined(CONFIG_S3C2400) || defined(CONFIG_S3C2410) || defined(CONFIG_LH7A40X) || defined(CONFIG_S3C2440)
（2）/include/s3c24x0.h文件的第85、95、99、110、148、404行：
将“#ifdef CONFIG_S3C2410”改为
#if defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
顺便在其中加入2440 的NAND FLASH 寄存器定义（第160行附近）和CAMDIVN定义（第128行附近）：
......
typedef struct {
S3C24X0_REG32 LOCKTIME;
S3C24X0_REG32 MPLLCON;
S3C24X0_REG32 UPLLCON;
S3C24X0_REG32 CLKCON;
S3C24X0_REG32 CLKSLOW;
S3C24X0_REG32 CLKDIVN;
#if defined (CONFIG_S3C2440)
S3C24X0_REG32 CAMDIVN;
#endif
} /*__attribute__((__packed__))*/ S3C24X0_CLOCK_POWER;
......
#if defined(CONFIG_S3C2410)
/* NAND FLASH (see S3C2410 manual chapter 6) */
typedef struct {
S3C24X0_REG32 NFCONF;
S3C24X0_REG32 NFCMD;
S3C24X0_REG32 NFADDR;
S3C24X0_REG32 NFDATA;
S3C24X0_REG32 NFSTAT;
S3C24X0_REG32 NFECC;
} /*__attribute__((__packed__))*/ S3C2410_NAND;
#endif
#if defined (CONFIG_S3C2440)
/* NAND FLASH (see S3C2440 manual chapter 6) */
typedef struct {
S3C24X0_REG32 NFCONF;
S3C24X0_REG32 NFCONT;
S3C24X0_REG32 NFCMD;
S3C24X0_REG32 NFADDR;
S3C24X0_REG32 NFDATA;
S3C24X0_REG32 NFMECC0;
S3C24X0_REG32 NFMECC1;
S3C24X0_REG32 NFSECC;
S3C24X0_REG32 NFSTAT;
S3C24X0_REG32 NFESTAT0;
S3C24X0_REG32 NFESTAT1;
S3C24X0_REG32 NFECC;
} /*__attribute__((__packed__))*/ S3C2410_NAND;
#endif
（3）/cpu/arm920t/s3c24x0/interrupts.c文件的第33行：
#if defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) || defined (CONFIG_S3C2440)
第38行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
在个文件中添加“defined(CONFIG_tekkaman2440)”，使得原来SBC2410X的代码可以编译进来。第181行:
#elif defined(CONFIG_SBC2410X) || \
defined(CONFIG_SMDK2410) || \
defined(CONFIG_VCMA9) ||defined(CONFIG_tekkaman2440)
（4）/cpu/arm920t/s3c24x0/serial.c文件的第22行：
#if defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) || defined (CONFIG_S3C2440)
第26行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
（5）/cpu/arm920t/s3c24x0/speed.c文件的第33行：
#if defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) || defined (CONFIG_S3C2440)
第37行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
顺便修改源代码，以匹配s3c2440：
static ulong get_PLLCLK(int pllreg)
{
......
m = ((r & 0xFF000) >> 12) + 8;
p = ((r & 0x003F0) >> 4) + 2;
s = r & 0x3;
//tekkaman
#if defined(CONFIG_S3C2440)
if (pllreg == MPLL)
return((CONFIG_SYS_CLK_FREQ * m * 2) / (p << s));
else if (pllreg == UPLL)
#endif
//tekkaman
return((CONFIG_SYS_CLK_FREQ * m) / (p << s));
}
......
/* return FCLK frequency */
ulong get_FCLK(void)
{
return(get_PLLCLK(MPLL));
}
/* return HCLK frequency */
ulong get_HCLK(void)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
//tekkaman
#if defined(CONFIG_S3C2440)
if (clk_power->CLKDIVN & 0x6)
{
if ((clk_power->CLKDIVN & 0x6)==2) return(get_FCLK()/2);
if ((clk_power->CLKDIVN & 0x6)==6) return((clk_power->CAMDIVN & 0x100) ? get_FCLK()/6 : get_FCLK()/3);
if ((clk_power->CLKDIVN & 0x6)==4) return((clk_power->CAMDIVN & 0x200) ? get_FCLK()/8 : get_FCLK()/4);
return(get_FCLK());
}
else return(get_FCLK());
#else
return((clk_power->CLKDIVN & 0x2) ? get_FCLK()/2 : get_FCLK());
#endif
//tekkaman
}
......
（6）/cpu/arm920t/s3c24x0/usb_ohci.c文件的第45行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
（7）drivers/rtc/s3c24x0_rtc.c文件的第35行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
（8）/cpu/arm920t/s3c24x0/usb.c文件的第31行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
（9）/cpu/arm920t/s3c24x0/i2c.c文件的第35行：
#elif defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
第66、85、142、150、174行：
将“#ifdef CONFIG_S3C2410”改为
#if defined(CONFIG_S3C2410) || defined (CONFIG_S3C2440)
（10）drivers/usb/usb_ohci.c文件的第68行附近：
#if defined(CONFIG_ARM920T) || \
defined(CONFIG_S3C2400) || \
defined(CONFIG_S3C2410) || \
defined(CONFIG_S3C2440) || \
defined(CONFIG_440EP) || \
defined(CONFIG_PCI_OHCI) || \
defined(CONFIG_MPC5200)
9、在 include/linux/mtd/nand_ids.h的结构体nand_flash_ids加入
static struct nand_flash_dev nand_flash_ids[] = {
......
{"Samsung K9F1208U0B", NAND_MFR_SAMSUNG, 0x76, 26, 0, 3, 0x4000, 0},
{NULL,}
};
修改include/linux/mtd/nand.h
/*
* Constants for hardware specific CLE/ALE/NCE function
*/
#if 0
/* Select the chip by setting nCE to low */
#define NAND_CTL_SETNCE 1
/* Deselect the chip by setting nCE to high */
#define NAND_CTL_CLRNCE 2
/* Select the command latch by setting CLE to high */
#define NAND_CTL_SETCLE 3
/* Deselect the command latch by setting CLE to low */
#define NAND_CTL_CLRCLE 4
/* Select the address latch by setting ALE to high */
#define NAND_CTL_SETALE 5
/* Deselect the address latch by setting ALE to low */
#define NAND_CTL_CLRALE 6
/* Set write protection by setting WP to high. Not used! */
#define NAND_CTL_SETWP 7
/* Clear write protection by setting WP to low. Not used! */
#define NAND_CTL_CLRWP 8
#endif
10、修改/lib_arm中的board.c。
......
#include <common.h>
#include <command.h>
#include <malloc.h>
#include <devices.h>
#include <version.h>
#include <net.h>
#include <s3c2410.h>
......
static int display_banner (void)
{
# if defined(CONFIG_tekkaman2440_LED)
S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
gpio->GPBDAT = 0x100; //tekkamanninja
//在串口初始化和console初始化完成，串口输出信息之前，LED1、LED2、LED3会亮起！
#endif
printf ("\n\n%s\n\n", version_string);
debug ("U-Boot code: %08lX -> %08lX BSS: -> %08lX\n",
_armboot_start, _bss_start, _bss_end);
#ifdef CONFIG_MODEM_SUPPORT
debug ("Modem Support enabled\n");
#endif
#ifdef CONFIG_USE_IRQ
debug ("IRQ Stack: %08lx\n", IRQ_STACK_START);
debug ("FIQ Stack: %08lx\n", FIQ_STACK_START);
#endif
return (0);
}
......
void start_armboot (void)
{
init_fnc_t **init_fnc_ptr;
char *s;
#ifndef CFG_NO_FLASH
ulong size;
#endif
#if defined(CONFIG_VFD) || defined(CONFIG_LCD)
unsigned long addr;
#endif
# if defined(CONFIG_tekkaman2440_LED)
S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
#endif
......
# if defined(CONFIG_tekkaman2440_LED)
gpio->GPBDAT = 0x0; //tekkamanninja
//在进入命令提示符之前，四个LED会同时亮起！
#endif
/* main_loop() can return to retry autoboot, if so just run it again. */
for (;;) {
main_loop ();
}
/* NOTREACHED - no way out of command loop except booting */
}
11、 修改common/env_nand.c
......
#ifdef CONFIG_INFERNO
#error CONFIG_INFERNO not supported yet
#endif
int nand_legacy_rw (struct nand_chip* nand, int cmd,
size_t start, size_t len,
size_t * retlen, u_char * buf);
extern struct nand_chip nand_dev_desc[CFG_MAX_NAND_DEVICE];
extern int nand_legacy_erase(struct nand_chip *nand, size_t ofs, size_t len, int clean);
/* info for NAND chips, defined in drivers/nand/nand.c */
extern nand_info_t nand_info[CFG_MAX_NAND_DEVICE];
......
#else /* ! CFG_ENV_OFFSET_REDUND */
int saveenv(void)
{
ulong total;
int ret = 0;
puts ("Erasing Nand...");
//if (nand_erase(&nand_info[0], CFG_ENV_OFFSET, CFG_ENV_SIZE))
if (nand_legacy_erase(nand_dev_desc + 0, CFG_ENV_OFFSET, CFG_ENV_SIZE, 0))
return 1;
puts ("Writing to Nand... ");
total = CFG_ENV_SIZE;
//ret = nand_write(&nand_info[0], CFG_ENV_OFFSET, &total, (u_char*)env_ptr);
ret = nand_legacy_rw(nand_dev_desc + 0,
0x00 | 0x02, CFG_ENV_OFFSET, CFG_ENV_SIZE,
&total, (u_char*)env_ptr);
if (ret || total != CFG_ENV_SIZE)
return 1;
puts ("done\n");
return ret;
......
#else /* ! CFG_ENV_OFFSET_REDUND */
/*
* The legacy NAND code saved the environment in the first NAND device i.e.,
* nand_dev_desc + 0. This is also the behaviour using the new NAND code.
*/
void env_relocate_spec (void)
{
#if !defined(ENV_IS_EMBEDDED)
ulong total;
int ret;
total = CFG_ENV_SIZE;
//ret = nand_read(&nand_info[0], CFG_ENV_OFFSET, &total, (u_char*)env_ptr);
ret = nand_legacy_rw(nand_dev_desc + 0, 0x01 | 0x02, CFG_ENV_OFFSET, CFG_ENV_SIZE, &total, (u_char*)env_ptr);
......
12、 在/board/tekkaman/tekkaman2440/tekkaman2440.c文件的末尾添加对Nand Flash 的初始化函数（在后面Nand Flash的操作都要用到）
u-boot运行至第二阶段进入start_armboot()函数。其中nand_init()函数是对nand flash的最初初始化函数。Nand_init()函数在两个文件中实现。其调用与CFG_NAND_LEGACY宏有关，如果没有定义这个宏，系统调用 drivers/nand/nand.c中的nand_init()；否则调用自己在board/tekkaman/tekkaman2440/tekkaman2440.c中的nand_init()函数。这里我选择第二种方式。
#if defined(CONFIG_CMD_NAND)
typedef enum {
NFCE_LOW,
NFCE_HIGH
} NFCE_STATE;
static inline void NF_Conf(u16 conf)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFCONF = conf;
}
static inline void NF_Cmd(u8 cmd)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFCMD = cmd;
}
static inline void NF_CmdW(u8 cmd)
{
NF_Cmd(cmd);
udelay(1);
}
static inline void NF_Addr(u8 addr)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFADDR = addr;
}
static inline void NF_WaitRB(void)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
while (!(nand->NFSTAT & (1<<0)));
}
static inline void NF_Write(u8 data)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFDATA = data;
}
static inline u8 NF_Read(void)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
return(nand->NFDATA);
}
static inline u32 NF_Read_ECC(void)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
return(nand->NFECC);
}
#if defined(CONFIG_S3C2440)
static inline void NF_Cont(u16 cont)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFCONT = cont;
}
static inline void NF_SetCE(NFCE_STATE s)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
switch (s) {
case NFCE_LOW:
nand->NFCONT &= ~(1<<1);
break;
case NFCE_HIGH:
nand->NFCONT |= (1<<1);
break;
}
}
static inline void NF_Init_ECC(void)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFCONT |= (1<<4);
}
#else
static inline void NF_SetCE(NFCE_STATE s)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
switch (s) {
case NFCE_LOW:
nand->NFCONF &= ~(1<<11);
break;
case NFCE_HIGH:
nand->NFCONF |= (1<<11);
break;
}
}
static inline void NF_Init_ECC(void)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
nand->NFCONF |= (1<<12);
}
#endif
extern ulong nand_probe(ulong physadr);
static inline void NF_Reset(void)
{
int i;
NF_SetCE(NFCE_LOW);
NF_Cmd(0xFF); /* reset command */
for(i = 0; i < 10; i++); /* tWB = 100ns. */
NF_WaitRB(); /* wait 200~500us; */
NF_SetCE(NFCE_HIGH);
}
static inline void NF_Init(void)
{
#if 0
#define TACLS 0
#define TWRPH0 3
#define TWRPH1 0
#else
#define TACLS 0
#define TWRPH0 4
#define TWRPH1 2
#endif
#if defined(CONFIG_S3C2440)
NF_Conf((TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4));
NF_Cont((1<<6)|(1<<4)|(1<<1)|(1<<0));
#else
NF_Conf((1<<15)|(0<<14)|(0<<13)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0));
/*nand->NFCONF = (1<<15)|(1<<14)|(1<<13)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0); */
/* 1 1 1 1, 1 xxx, r xxx, r xxx */
/* En 512B 4step ECCR nFCE=H tACLS tWRPH0 tWRPH1 */
#endif
NF_Reset();
}
void nand_init(void)
{
S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
NF_Init();
#ifdef DEBUG
printf("NAND flash probing at 0x%.8lX\n", (ulong)nand);
#endif
printf ("%4lu MB\n", nand_probe((ulong)nand) >> 20);
}
#endif
三、交叉编译U－Boot。
在U－Boot的根目录下
$make
/2 
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