Hi, I have got a great break through! It seems to be a memory problem!I have replaced NIC Realtck 8139 with Intel e100, and there is no more "checksum error now". But it still hang with the second TFTP packet, leaving me:ok 4200 Data Access Error ...
I have tried again as follows: ok boot net .... 4400 Data Access Error ok dump 4000 600 .... 0 Fast Data Access MMU Miss I think this "MMU Miss" message is an important clue. -- 续本达 Xu, Benda Fundamental Science of Mathematics and Physics, Tsinghua University, Beijing, P.R.China http://learn.tsinghua.edu.cn:8080/2005012177/index.html http://thirsty.phys.tsinghua.edu.cn/MyWiki/heroxbd