Improve interactive shell #66
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By using `-serial mon:stdio` we multiplex the guest'serial console and QEMU monitor to the host's stdio. This gives us 2 features in interactive mode: 1) Access to the monitor via the `Ctrl-c a` keybinding 2) Intercept Ctrl-c and pass it to the guest instead of killing the guest. In non-interactive mode, stdio is not hooked to qemu and this is a no-op. https://www.qemu.org/docs/master/system/qemu-manpage.html#hxtool-9 ``` mon:dev_string This is a special option to allow the monitor to be multiplexed onto another serial port. The monitor is accessed with key sequence of Control-a and then pressing c. dev_string should be any one of the serial devices specified above. An example to multiplex the monitor onto a telnet server listening on port 4444 would be: -serial mon:telnet::4444,server=on,wait=off When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate QEMU any more but will be passed to the guest instead. ``` Testing: In interactive mode, typed `Ctrl-a h` ``` root@(none):/# C-a h print this help C-a x exit emulator C-a s save disk data back to file (if -snapshot) C-a t toggle console timestamps C-a b send break (magic sysrq) C-a c switch between console and monitor C-a C-a sends C-a ``` and confirmed that Ctrl-c did not kill the guest. Signed-off-by: Manu Bretelle <[email protected]>
Upon boot up, bash was reporting: ``` bash: cannot set terminal process group (-1): Inappropriate ioctl for device bash: no job control in this shell ``` and as a side-effect, Ctrl-C,Ctrl-Z.... were disabled. This change makes use of `setsid` to exec `bash` and setting the controlling terminal to the current one. This let `bash` successfully set up job control. https://stackoverflow.com/a/77840840 has a detailed explanation. Signed-off-by: Manu Bretelle <[email protected]>
It will not as ran at the time, for a couple of reasons I can think of.
But maybe in this specific case the solution to @javierhonduco issue is to drop in an interactive shell and run the command. Then signals will be forwarded from stdin to the guest's terminal. |
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Make it possible to use job control in interactive shell.
Before this change, when dropped in an interactive shell, Ctrl-C would kill the whole qemu process.
to make this work, we need 2 things:
-serial mon:stdioinstead of-serial stdio.