[U-Boot] U-boot1.1.6 calloc problem

Hey all,   U-boot1.1.6,whitch I ported to my board S3C44B0 ,it worked very well for few days, but something was wrong today. What I got from serial: ------------------------------------------------------------------------ U-boot1.1.6   DRAM: 8M Flash : 2M ----------------------------------------------------------------------- after tracing functions by using "printf" command,I found the problem was "devlist=NULL". then I went deep,found the function "NewHandle" ,whitch is related to Create empty List. It returned "NULL" ,and the problem is command "calloc".   any help is appreciated.   regards , John