001
002 By default, with qemu version < 0.8.0 and with the command line
003 qemu -monitor pty or -serial pty, local echo is
004 enabled for the qemu side of the pty. This can result in infinite
005 write/read loops and/or slowness of the simulation. Attached is a very
006 small patch (against today's cvs) solving the problem. The 3 lines
007 adjusting the tty fields could be replaced by "cfmakeraw(&tty)" if
008 available on the host platform.
009
010 -- David Decotigny (Dec 9 2005)
011
012
013 Index: vl.c
014 ===================================================================
015 RCS file: /cvsroot/qemu/qemu/vl.c,v
016 retrieving revision 1.152
017 diff -u -r1.152 vl.c
018 --- vl.c 5 Dec 2005 20:31:52 -0000 1.152
019 +++ vl.c 9 Dec 2005 15:07:46 -0000
020 @@ -1396,6 +1396,7 @@
021 #if defined(__linux__)
022 CharDriverState *qemu_chr_open_pty(void)
023 {
024 + struct termios tty;
025 char slave_name[1024];
026 int master_fd, slave_fd;
027
028 @@ -1403,6 +1404,14 @@
029 if (openpty(&master_fd, &slave_fd, slave_name, NULL, NULL) < 0) {
030 return NULL;
031 }
032 +
033 + /* Disabling local echo and line-buffered output */
034 + tcgetattr (master_fd, &tty);
035 + tty.c_lflag &= ~(ECHO|ICANON|ISIG);
036 + tty.c_cc[VMIN] = 1;
037 + tty.c_cc[VTIME] = 0;
038 + tcsetattr (master_fd, TCSAFLUSH, &tty);
039 +
040 fprintf(stderr, "char device redirected to %s\n", slave_name);
041 return qemu_chr_open_fd(master_fd, master_fd);
042 }