Hi All, I wanted to start my hands on on Linux kernel and got stuck at the beginning with build failure. ( I have tried this few months back when it worked fine but failing after upgrade.) with following error: Root device is (8, 6) Setup is 14108 bytes (padded to 14336 bytes). System is 4423 kB CRC 4e90e12c Kernel: arch/x86/boot/bzImage is ready (#1) Building modules, stage 2. MODPOST 3274 modules ERROR: "pm_idle" [arch/x86/kernel/apm.ko] undefined! ERROR: "default_idle" [arch/x86/kernel/apm.ko] undefined! WARNING: modpost: Found 30 section mismatch(es). To see full details build your kernel with: 'make CONFIG_DEBUG_SECTION_MISMATCH=y' make[1]: *** [__modpost] Error 1 make: *** [modules] Error 2 ssreddy@N5030:~/linux-2.6$ I am looking to dedicate few hours every week from now. I am refraining from attaching the .config file to wider list. I can send in unicast if some one is willing to help me fix if there are problems in .config. I have copied the old config file from installed ubuntu 11.04 yes ' ' | make oldconfig -- to generate my basic config file. Thanks, SADA