Hi Alex, I downloaded your images and ran them on one of our machines using pxeboot and all of the tests passed. I've attached a log for you. Given that you are constructing valid images, the error must be somewhere in the loading process. I notice that your log mentions loading "rootserver" but the file you sent me is called "sel4rootserver". You manage to successfully load the kernel, but then the file loaded as the roottask is empty (Assuming that BOOT MODULE is dumping the contents of the addresses that the root task is loaded at). Other things to check other than the filename is file permissions that both of the files have and whether the tftp server is serving every file in the same directory or just specific files. As for x86_64 not giving any output, are you also using -DRELEASE? I noticed that the images you sent had debug symbols stripped, which shouldn't be the case with only -DPLATFORM=ia32/x86_64 set. If the kernel is crashing before starting userlevel while in release mode you won't get any output. However, I'd probably try and get ia32 working before going back to debugging x86_64. Good luck. Kind regards, Kent.