Re: [kvm-unit-tests RFC 2/3] lib: s390x: sclp: Clear ASCII screen on setup

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Fri, 30 Jun 2023 14:54:48 +0000
Janosch Frank <frankja@linux.ibm.com> wrote:

> In contrast to the line-mode console the ASCII console will retain

what's the problem with that?

> previously written text on a reboot. So let's clear the console on
> setup so only our text will be displayed. To not clear the whole
> screen when running under QEMU we switch the run command to the line
> mode console.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/sclp-console.c | 2 ++
>  s390x/run                | 2 +-
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c
> index 384080b0..534d3443 100644
> --- a/lib/s390x/sclp-console.c
> +++ b/lib/s390x/sclp-console.c
> @@ -233,6 +233,8 @@ void sclp_console_setup(void)
>  {
>  	/* We send ASCII and line mode. */
>  	sclp_write_event_mask(0, SCLP_EVENT_MASK_MSG_ASCII | SCLP_EVENT_MASK_MSG);
> +	/* Hard terminal reset to clear screen */
> +	sclp_print_ascii("\ec");
>  }
>  
>  void sclp_print(const char *str)
> diff --git a/s390x/run b/s390x/run
> index f1111dbd..68f8e733 100755
> --- a/s390x/run
> +++ b/s390x/run
> @@ -28,7 +28,7 @@ fi
>  M='-machine s390-ccw-virtio'
>  M+=",accel=$ACCEL"
>  command="$qemu -nodefaults -nographic $M"
> -command+=" -chardev stdio,id=con0 -device sclpconsole,chardev=con0"
> +command+=" -chardev stdio,id=con0 -device sclplmconsole,chardev=con0"
>  command+=" -kernel"
>  command="$(panic_cmd) $(migration_cmd) $(timeout_cmd) $command"
>