diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2024-01-22 16:36:07 +0000 |
|---|---|---|
| committer | Michael Tokarev <mjt@tls.msk.ru> | 2024-02-03 16:43:46 +0300 |
| commit | f039059e0a1cc3cebb74d60096ba2cad05e9dfd5 (patch) | |
| tree | 4d0386a7da7092f37e0a5f6b63ad5fba484cb82e | |
| parent | 597a9a2b4b18323c20538008cd3ded85de76e9fa (diff) | |
qemu-options.hx: Improve -serial option documentation
The -serial option documentation is a bit brief about '-serial none'
and '-serial null'. In particular it's not very clear about the
difference between them, and it doesn't mention that it's up to
the machine model whether '-serial none' means "don't create the
serial port" or "don't wire the serial port up to anything".
Expand on these points.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240122163607.459769-3-peter.maydell@linaro.org
(cherry picked from commit 747bfaf3a9d2f3cd51674763dc1f7575100cd200)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
| -rw-r--r-- | qemu-options.hx | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/qemu-options.hx b/qemu-options.hx index 379692da86..7f798ce47e 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3968,7 +3968,8 @@ SRST This option can be used several times to simulate up to 4 serial ports. - Use ``-serial none`` to disable all serial ports. + You can use ``-serial none`` to suppress the creation of default + serial devices. Available character devices are: @@ -3990,10 +3991,17 @@ SRST [Linux only] Pseudo TTY (a new PTY is automatically allocated) ``none`` - No device is allocated. + No device is allocated. Note that for machine types which + emulate systems where a serial device is always present in + real hardware, this may be equivalent to the ``null`` option, + in that the serial device is still present but all output + is discarded. For boards where the number of serial ports is + truly variable, this suppresses the creation of the device. ``null`` - void device + A guest will see the UART or serial device as present in the + machine, but all output is discarded, and there is no input. + Conceptually equivalent to redirecting the output to ``/dev/null``. ``chardev:id`` Use a named character device defined with the ``-chardev`` |