S3C6410开发板实践实录2

硬件平台：

MainBoard:OK6410
CPU: S3C6410
RAM: 256M
FLASH:1G K9GAG08U0D

Kernel:Linux2.6.28

BootLoader:Uboot1.1.6

 

3.使用TFTP升级Uboot

 

发现使用tftp升级uboot的时候无法成功，但是升级fs和kernel的时候可以。
后发现S3C6410启动的时候会通过 NAND控制器将nandflash的头4K拷贝到SRAM中执行，这一步叫做steppingstone，SRAM的大小有8K，但是 steppingstone只用了其中的4K，另外NAND控制器支持每FLASH页读取的大小为512B/2K，所以当flash页大小为4K的时候， 它只能每块读取前2K，这里就需要在写Uboot的时候前面个PAGE每个只能写入2K，也即

 

nand erase 0 100000
nand write 50008000 0 1000
nand write 50008800 1000 1000
nand write 50009000 2000 FF000

飞凌提供的SD卡升级方式利用了SDRAM的全部大小，也即8K，所以它的写入步骤为：

nand erase 0 100000
nand write 50008000 0 1000
nand write 50008800 1000 1000
nand write 50009000 2000 1000
nand write 50009800 3000 1000
nand write 5000A000 4000 FE000

至此解决了TFTP升级Uboot问题。另外在do_nane中添加了命令nand write.uboot命令，可以直接一个命令搞定uboot升级，添加如下代码：

 

else if(!read && !strcmp(s, ".uboot"))
        {
            /* for Page 2048 then just do normal writing */
            if(nand->writesize == 0x800)
                goto write;
            else if(nand->writesize == 0x1000)
            {
                /* try to simulate a 0x800 page size flash and do a remap */
                int blocks = 5, i = 0;

                for(; i < blocks; i++)
                {
                    if(i == blocks - 1)
                        size = 0xfe000;
                    else
                        size = 0x1000;

                    printf("Write at Offset %x from Addr:%x with Size %x\n", off + i * 0x1000, addr + i * 0x800, size);
                    ret = nand_write(nand, off + i * 0x1000, &size, (u_char *)(addr + i * 0x800));

                    if(ret == 0)
                    {
                        uint *magic = (uint*)(PHYS_SDRAM_1);
                        if((0x24564236 == magic[0]) && (0x20764316 == magic[1]))
                        magic[0] = 0x27051956;
                    }

                    if(ret)
                    {
                        printf(" 0x%x bytes %s to 0x%x %s\n", size, read ? "read" : "written", off + i * 0x1000, 0x1000,
                                    ret ? "ERROR" : "OK");
                        return 1;
                    }
                }

                printf("Uboot have been updated, please do reset!\n");
                return 0;
            }
            else
            {
                printf("Only support page size 2K and 4K!\n");
                return 1;
            }
        }