static CharDriverState *qemu_chr_open_stdio(QemuOpts *opts) { CharDriverState *chr; if (stdio_nb_clients >= STDIO_MAX_CLIENTS) { if (stdio_nb_clients == 0) { old_fd0_flags = fcntl(0, F_GETFL); tcgetattr (0, &oldtty); fcntl(0, F_SETFL, O_NONBLOCK); atexit(term_exit); chr = qemu_chr_open_fd(0, 1); chr->chr_close = qemu_chr_close_stdio; chr->chr_set_echo = qemu_chr_set_echo_stdio; qemu_set_fd_handler2(0, stdio_read_poll, stdio_read, NULL, chr); stdio_nb_clients++; stdio_allow_signal = qemu_opt_get_bool(opts, "signal", display_type != DT_NOGRAPHIC); qemu_chr_fe_set_echo(chr, false); return chr;