2）在Makefile中加入
bks2410_config:unconfig
@./mkconfig $(@:_config=) arm arm920t bks2410 NULL s3c24x0
我把我的板子起名叫bks2410，可以依自己的喜好修改

3）建立board/bks2410目錄，拷貝board/smdk2410下的文件到board/bks2410目錄，將smdk2410.c更名為bks2410.c

4）cp include/configs/smdk2410.h include/configs/bks2410.h

5）將arm-linux-gcc的目錄加入到PATH環(huán)境變量中，我的是目錄/opt/eldk/usr/bin:/opt/eldk/bin

6）測(cè)試編譯能否成功：
make bks2410_config
make all ARCH=arm
生成u-boot.bin就OK了

7）依照你自己開(kāi)發(fā)板的內(nèi)存地址分配情況修改board/bks2410/memsetup.S文件，我的程序：
#include
#include

#define BWSCON0x48000000

/* BWSCON */
#define DW8 (0x0)
#define DW16 (0x1)
#define DW32 (0x2)
#define WAIT (0x1<<2)
#define UBLB (0x1<<3)

#define B1_BWSCON (DW32)
#define B2_BWSCON (DW16)
#define B3_BWSCON (DW16 + WAIT + UBLB)
#define B4_BWSCON (DW16)
#define B5_BWSCON (DW16)
#define B6_BWSCON (DW32)
#define B7_BWSCON (DW32)

/* BANK0CON */
#if 0
#define B0_Tacs 0x0/* 0clk */
#define B0_Tcos 0x0/* 0clk */
#define B0_Tacc 0x7/* 14clk */
#define B0_Tcoh 0x0/* 0clk */
#define B0_Tah 0x0/* 0clk */
#define B0_Tacp 0x0
#define B0_PMC 0x0/* normal */
#endif

#define B0_Tacs 0x3/* 0clk */
#define B0_Tcos 0x3/* 0clk */
#define B0_Tacc 0x7/* 14clk */
#define B0_Tcoh 0x3/* 0clk */
#define B0_Tah 0x3/* 0clk */
#define B0_Tacp 0x1
#define B0_PMC 0x0/* normal */

/* BANK1CON */
#if 0
#define B1_Tacs 0x0/* 0clk */
#define B1_Tcos 0x0/* 0clk */
#define B1_Tacc 0x7/* 14clk */
#define B1_Tcoh 0x0/* 0clk */
#define B1_Tah 0x0/* 0clk */
#define B1_Tacp 0x0
#define B1_PMC 0x0
#endif

#define B1_Tacs 0x3/* 0clk */
#define B1_Tcos 0x3/* 0clk */
#define B1_Tacc 0x7/* 14clk */
#define B1_Tcoh 0x3/* 0clk */
#define B1_Tah 0x3/* 0clk */
#define B1_Tacp 0x3
#define B1_PMC 0x0

#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

#if 0
#define B3_Tacs 0x0/* 0clk */
#define B3_Tcos 0x3/* 4clk */
#define B3_Tacc 0x7/* 14clk */
#define B3_Tcoh 0x1/* 1clk */
#define B3_Tah 0x0/* 0clk */
#define B3_Tacp 0x3 /* 6clk */
#define B3_PMC 0x0/* normal */
#endif

#define B3_Tacs 0x0/* 0clk */
#define B3_Tcos 0x0/* 4clk */
#define B3_Tacc 0x7/* 14clk */
#define B3_Tcoh 0x0/* 1clk */
#define B3_Tah 0x0/* 0clk */
#define B3_Tacp 0x0 /* 6clk */
#define B3_PMC 0x0/* normal */

#define B4_Tacs 0x0/* 0clk */
#define B4_Tcos 0x0/* 0clk */
#define B4_Tacc 0x7/* 14clk */
#define B4_Tcoh 0x0/* 0clk */
#define B4_Tah 0x0/* 0clk */
#define B4_Tacp 0x0
#define B4_PMC 0x0/* normal */

#define B5_Tacs 0x0/* 0clk */
#define B5_Tcos 0x0/* 0clk */
#define B5_Tacc 0x7/* 14clk */
#define B5_Tcoh 0x0/* 0clk */
#define B5_Tah 0x0/* 0clk */
#define B5_Tacp 0x0
#define B5_PMC 0x0/* normal */

#define B6_MT 0x3/* SDRAM */
#define B6_Trcd 0x1
#define B6_SCAN 0x1/* 9bit */

#define B7_MT 0x3/* SDRAM */
#define B7_Trcd 0x1/* 3clk */
#define B7_SCAN 0x1/* 9bit */

/* REFRESH parameter */
#define REFEN 0x1/* Refresh enable */
#define TREFMD 0x0/* CBR(CAS before RAS)/Auto refresh */
#define Trp 0x0/* 2clk */
#define Trc 0x3/* 7clk */
#define Tchr 0x2/* 3clk */
#define REFCNT 1113/* period=15.6us, HCLK=60Mhz, (2048+1-15.6*60) */
/**************************************/

_TEXT_BASE:
.wordTEXT_BASE

.globl memsetup
memsetup:
/* memory control configuration */
/* make r0 relative the current location so that it */
/* reads SMRDATA out of FLASH rather than memory ! */
adr r0, SMRDATA
/*ldrr1, _TEXT_BASE*/
/*subr0, r0, r1*/
ldrr1, =BWSCON/* Bus Width Status Controller */
add r2, r0, #13*4
0:
ldr r3, [r0], #4
str r3, [r1], #4
cmp r2, r0
bne 0b

/* everything is fine now */
movpc, lr

.ltorg
/* the literal pools origin */

SMRDATA:
.word (0+(B1_BWSCON<<4)+(B2_BWSCON<<8)+(B3_BWSCON<<12)+(B4_BWSCON<<16)+(B5_BWSCON<<20)+(B6_BWSCON<<24)+(B7_BWSCON<<28))
.word ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC))
.word ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC))
.word ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC))
.word 0x1f7c/*((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC))*/
.word ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC))
.word ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC))
.word ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN))
.word ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN))
.word ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+(Tchr<<16)+REFCNT)
.word 0x31
.word 0x30
.word 0x30

8）在board/bks2410加入NAND Flash讀函數(shù)，建立nand_read.c，加入如下內(nèi)容(copy from vivi)：
#include

#define __REGb(x)(*(volatile unsigned char *)(x))
#define __REGi(x)(*(volatile unsigned int *)(x))
#define NF_BASE0x4e000000
#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++);
}

#define NAND_SECTOR_SIZE512
#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 */
}

/* 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;
}

9）修改board/bks2410/Makefile為
OBJS:= bks2410.o flash.o nand_read.o

10）修改cpu/arm920t/start.S文件
在ldrpc, _start_armboot之前加入：
#ifdef CONFIG_S3C2410_NAND_BOOT
bl copy_myself

@ jump to ram
ldr r1, =on_the_ram
add pc, r1, #0
nop
nop
1: b 1b @ infinite loop

on_the_ram:
#endif

在_start_armboot:.word start_armboot之后加入：
#ifdef CONFIG_S3C2410_NAND_BOOT
copy_myself:
mov r10, lr
@ 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

1:add r3, r3, #0x1
cmp r3, #0xa
blt 1b
2:ldr r2, [r1, #oNFSTAT] @ wait ready
tst r2, #0x1
beq 2b
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 vivi to RAM
ldr r0, =UBOOT_RAM_BASE
mov r1, #0x0
mov r2, #0x20000
bl nand_read_ll
tst r0, #0x0
beq ok_nand_read

#ifdef CONFIG_DEBUG_LL
bad_nand_read:
ldr r0, STR_FAIL
ldr r1, SerBase
bl PrintWord
1:b 1b @ infinite loop
#endif

ok_nand_read:
#ifdef CONFIG_DEBUG_LL
ldr r0, STR_OK
ldr r1, SerBase
bl PrintWord
#endif

@ verify
mov r0, #0
ldr r1, =UBOOT_RAM_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 done_nand_read
bne go_next

notmatch:
#ifdef CONFIG_DEBUG_LL
sub r0, r0, #4
ldr r1, SerBase
bl PrintHexWord
ldr r0, STR_FAIL
ldr r1, SerBase
bl PrintWord
#endif
1:b 1b
done_nand_read:
#ifdef CONFIG_DEBUG_LL
ldr r0, STR_OK
ldr r1, SerBase
bl PrintWord
#endif
mov pc, r10
@ clear memory
@ r0: start address
@ r1: length
mem_clear:
mov r2, #0
mov r3, r2
mov r4, r2
mov r5, r2
mov r6, r2
mov r7, r2
mov r8, r2
mov r9, r2

clear_loop:
stmia r0!, {r2-r9}
subs r1, r1, #(8 * 4)
bne clear_loop
mov pc, lr

#endif @ CONFIG_S3C2410_NAND_BOOT

在文件的最后加入：
.align 2
DW_STACK_START:
.word STACK_BASE+STACK_SIZE-4

11）修改include/configs/bks2410.h文件，添加如下內(nèi)容：
/*
* 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

12）重新編譯u-boot
make all ARCH=arm

13）通過(guò)jtag將u-boot燒寫到flash中就可以從NAND flash啟動(dòng)了

我的u-boot啟動(dòng)信息：

U-Boot 1.1.3 (May 6 2006 - 18:13:59)

U-Boot code: 33F80000 -> 33F967C4 BSS: -> 33F9AAAC
RAM Configuration:
Bank #0: 30000000 64 MB
Flash: 512 kB
*** Warning - bad CRC, using default environment

In: serial
Out: serial
Err: serial
BKS2410 #