Re: [PATCH] tools: kwboot: Allow to specify custom baudrate only in supported operations

["Marek Behún" <marek.behun@nic.cz>]

On Sun,  6 Mar 2022 13:38:30 +0100
Pali Rohár <pali@kernel.org> wrote:

> Custom baudrate different than 115200 may be specified only when kwboot is
> not going to send boot/debug message pattern or when it is going to send
> boot message pattern with image file (in which case baudrate change happens
> after sending kwbimage header). BootROM detects boot/debug message pattern
> only at baudrate 115200.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
>  tools/kwboot.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/kwboot.c b/tools/kwboot.c
> index 69d1be0f4823..f975c4a6c6ca 100644
> --- a/tools/kwboot.c
> +++ b/tools/kwboot.c
> @@ -2128,6 +2128,10 @@ main(int argc, char **argv)
>  	if (!bootmsg && !term && !debugmsg && !imgpath)
>  		goto usage;
>  
> +	/* boot and debug message use baudrate 115200 */
> +	if (((bootmsg && !imgpath) || debugmsg) && baudrate != 115200)
> +		goto usage;

Maybe this should print an actual error message describing the problem?
Otherwise the user might not understand why they are getting usage...

Marek