android init进程启动流程

Android系统完整的启动流程

android 系统架构图

init进程的启动流程

init进程启动服务的顺序

bool Service::Start() {
    // Starting a service removes it from the disabled or reset state and
    // immediately takes it out of the restarting state if it was in there.
    flags_ &= (~(SVC_DISABLED|SVC_RESTARTING|SVC_RESET|SVC_RESTART|SVC_DISABLED_START));

    // Running processes require no additional work --- if they're in the
    // process of exiting, we've ensured that they will immediately restart
    // on exit, unless they are ONESHOT.
    if (flags_ & SVC_RUNNING) {
        return false;
    }

    bool needs_console = (flags_ & SVC_CONSOLE);
    if (needs_console) {
        if (console_.empty()) {
            console_ = default_console;
        }

        // Make sure that open call succeeds to ensure a console driver is
        // properly registered for the device node
        int console_fd = open(console_.c_str(), O_RDWR | O_CLOEXEC);
        if (console_fd < 0) {
            PLOG(ERROR) << "service '" << name_ << "' couldn't open console '" << console_ << "'";
            flags_ |= SVC_DISABLED;
            return false;
        }
        close(console_fd);
    }

    struct stat s