移植u-boot到s3c2410开发板（Nand Flash）1

本文参考结合网上多篇文章，经过实践验证，证明可行。实验环境：CITK2410开发板(华南农业大学信息学院研发)，u-boot 1.2.0，arm-linux-gcc 3.3.2，Linux Kernel 2.6.14.2。约定：下文中蓝色框内为需要添加修改的内容，上下文仅作定位之用。

 

Port u-boot to s3c2410

１、           下载u-boot-1.2.0.tar.bz2,并解压

２、           设置交叉编译环境变量

export PATH=/usr/local/arm/3.3.2/bin:$PATH

３、           编辑u-boot根目录的Makefile文件

 

smdk2410_config    :      unconfig

    @$(MKCONFIG) $(@:_config=) arm arm920t smdk2410 NULL s3c24x0

 

jan2410_config : unconfig

@$(MKCONFIG) $(@:_config=) arm arm920t jan2410 NULL s3c24x0

 

SX1_config :            unconfig

    @$(MKCONFIG) $(@:_config=) arm arm925t sx1

 

 

４、           复制必要的文件

cp -arf board/smdk2410/ board/jan2410

mv board/jan2410/smdk2410.c board/jan2410/jan2410.c

cp include/configs/smdk2410.h include/configs/jan2410.h

 

 

５、           修改board/ jan2410/Makefile

LIB     = $(obj)lib$(BOARD).a

 

COBJS      := jan2410.o flash.o

SOBJS      := lowlevel_init.o

 

 

 

６、           修改文件cpu/arm920t/config.mk

PLATFORM_CPPFLAGS +=$(call cc-option,-mapcs-32,-mabi=apcs-gnu)

改成：

PLATFORM_CPPFLAGS +=$(call cc-option,-mapcs-32,$(call cc-option,-mabi=apcs-gnu),)

 

make 测试一下

make jan2410_config

make ARCH=arm

 

７、           添加网络命令

在include/configs/jan2410.h

只要在

#define CONFIG_COMMANDS

添加定义

                  (CONFIG_CMD_DFL      | \

                  CFG_CMD_CACHE | \

                  /*CFG_CMD_NAND       |*/ \

                  /*CFG_CMD_EEPROM |*/ \

                  /*CFG_CMD_I2C     |*/ \

                  /*CFG_CMD_USB    |*/ \

                  CFG_CMD_REGINFO  | \

                  CFG_CMD_DATE     | \

                  CFG_CMD_ELF | \

                  CFG_CMD_NET       | \

                  CFG_CMD_PING)

就可以了

 

 

８、           开始移植nand

修改cpu/arm920t/start.S

 

将从Flash启动改成从NAND Flash启动。

将以下U－Boot的重定向语句段：

 

#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    r0!, {r3-r10}        /* copy from source address [r0]    */

    stmia    r1!, {r3-r10}        /* copy to   target address [r1]    */

    cmp    r0, r2            /* until source end addreee [r2]    */

    ble    copy_loop

#endif    /* CONFIG_SKIP_RELOCATE_UBOOT */

 

 

 

替换成：

 

#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, #0x20000

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 “ _start_armboot:    .word start_armboot ” 后加入：

    .align     2

DW_STACK_START: .word STACK_BASE+STACK_SIZE-4

 

 

９、            

1)        修改board/sky2410/lowlevel_init.S

这文件主要是设置一些依赖于开发板的参数，如内存时序等。如有必要，可以根据自己的开发板修改。

 

2)        创建board/jan2410/nand_read.c文件

#include

#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

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;

}

 

3)        修改board/jan2410/Makefile

COBJS      := jan2410.o flash.o nand_read.o

 

１０、   修改include/configs/jan2410.h

在文件的后部（#endif /* __CONFIG_H */前）添加

/*

* Nandflash Boot

*/

#define CONFIG_S3C2410_NAND_BOOT 1

#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

#define oNFCMD                0x04

#define oNFADDR               0x08

#define oNFDATA               0x0c

#define oNFSTAT               0x10

#define oNFECC                0x14

 

（文章长度限制。。。接2）