移植u-boot的问题 FL2440
#ifdef CONFIG_S3C2440_NAND_BOOTmov r1, #NAND_CTL_BASE //复位Nand Flash
ldr r2, =( (7<<12)|(7<<8)|(7<<4)|(0<<0) )
str r2, //设置配置寄存器的初始值，参考s3c2440手册
ldr r2,
ldr r2, =( (1<<4)|(0<<1)|(1<<0) )
str r2, //设置控制寄存器
ldr r2,
ldr r2, =(0x6) //RnB Clear
str r2,
ldr r2,
mov r2, #0xff //复位command
strb r2,
mov r3, #0 //等待
nand1:
add r3, r3, #0x1
cmp r3, #0xa
blt nand1
nand2:
ldr r2, //等待就绪
tst r2, #0x4
beq nand2
ldr r2,
orr r2, r2, #0x2 //取消片选
str r2,
//get read to call C functions (for nand_read())
ldr sp, DW_STACK_START //为C代码准备堆栈,DW_STACK_START定义在下面
mov fp, #0
//copy U-Boot to RAM
ldr r0, =TEXT_BASE//传递给C代码的第一个参数：u-boot在RAM中的起始地址
mov r1, #0x0 //传递给C代码的第二个参数：Nand Flash的起始地址
mov r2, #0x30000//传递给C代码的第三个参数：u-boot的长度大小(128k)
bl nand_read_ll //此处调用C代码中读Nand的函数，现在还没有要自己编写实现
tst r0, #0x0
beq ok_nand_read
bad_nand_read:
loop2: b loop2 //infinite loop
ok_nand_read:
//检查搬移后的数据，如果前4k完全相同，表示搬移成功
mov r0, #0
ldr r1, =TEXT_BASE
mov r2, #0x400 //4 bytes * 1024 = 4K-bytes
go_next:
ldr r3, , #4
ldr r4, , #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
_start_armboot: .word start_armboot //在这一句的下面加上DW_STACK_START的定义
.align 2
DW_STACK_START: .word STACK_BASE+STACK_SIZE-4
#include <config.h>
#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 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 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 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
为什么u-boot一直在循环运行nand_read_ll，我测试过（通过led），串口没有任何输出，请斑竹帮我修改一下！
我是在我原来的u-boot基础上修改的，原来的u-boot能在s3c2440运行，能正确引导和输出！
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