Hi,everybody! I am new to u-boot.These days ,I am porting u-boot to a changed SMDK2410 .There is a dm9000a chip replacing the cs8900,and I don't use ROM for dm9000a.So I have used a static data struct(C langue)to replace reading MAC from the ROM.While it seems to wrong: when I not configed CONFIG_DM9000_DEBUG,there would be timeout,the serial printed something like this :##TTTTTTT##TTTTTT,but ,as long as configed it,the TFTP works very well,about 10k/ps. I am sorry to disturbed you,best wishes! Thank you,everyone! hongyualang