Thanks All!!!! What I want to know is how PMON jump to linux kernel image, when mips.S function "_go" execute "j k0" command, (k0 is assigned by LREG(k0,R_EPC,gp) /* EPC */) k0 will be 40*(DBGREG)=40* (0x7ff00bad), the address is kuseg's domain. is it really work to turnin linux kernel image?? (In common case, linux kernl image always start from 0x100000) any suggestion? I just want to know MORE about the LINK method between PMON and MIPS-Linux? best regards, --Ku