I try to start Android on device via NFS and TFTP. Everything goes good until Android system starts booting. Something happens with network parameters and connection falls and boot freezes [   60.881134] nfs: server 128.247.77.158 not responding, still trying I've decided to try add parameter to mount command such as bg, intr and hard. Is it possible to configure this parameters before system boot? Or should I modify flags in kernel code (somewhere here)? 
Add parameters to NFS mount
linux;networking;boot;nfs;root filesystem
I have found the solution of my problem. When Android starts it makes flush of all rules. The code that does this work I found in file system/netd/RouteController.cpp function int flushRules(). When I have blocked execution of code of this function I haven't seen message about NFS connection loose anymore.// Returns 0 on success or negative errno on failure.WARN_UNUSED_RESULT int flushRules() {    return 0;//TODO workaround of NFS parameters reset     for (size_t i = 0; i < ARRAY_SIZE(IP_VERSIONS); ++i) {        const char* argv[] = {            IP_PATH,            IP_VERSIONS[i],            rule,            flush,        };        if (android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, false, false)) {            ALOGE(failed to flush rules);            return -EREMOTEIO;        }    }    return 0;} And now Android system boots with NFS as expected. 