[PATCH v5 07/17] bootmenu: flush input buffer before waiting user key input

[Heinrich Schuchardt]

On 4/28/22 10:09, Masahisa Kojima wrote:
> Before waiting user key input to stop autoboot, the input buffer
> must be flushed.

I am not sure if this is desirable.

The default time for autoboot stopping is just 2 seconds. So it is nice
to be able to type ahead.

On the other hand I have seen boards not booting because after the
serial driver was initialized it found some random byte in the input buffer.

I would prefer flushing of input in serial_init().

Best regards

Heinrich

>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
> Change in v5:
> - newly created, split into separate patch
>
>   cmd/bootmenu.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/cmd/bootmenu.c b/cmd/bootmenu.c
> index d573487272..9a32a18b19 100644
> --- a/cmd/bootmenu.c
> +++ b/cmd/bootmenu.c
> @@ -87,6 +87,10 @@ static void bootmenu_autoboot_loop(struct bootmenu_data *menu,
>   	int i, c;
>
>   	if (menu->delay > 0) {
> +		/* flush input */
> +		while (tstc())
> +			getchar();
> +
>   		printf(ANSI_CURSOR_POSITION, menu->count + 5, 1);
>   		printf("  Hit any key to stop autoboot: %2d ", menu->delay);
>   	}