[U-Boot] [PATCH] pxe: automatically add console= to bootargs when not specified in append

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/01/2014 01:46 AM, Hans de Goede wrote:
> From: Dennis Gilmore <dennis@ausil.us>
>
> if there is a console variable in the u-boot environment and not one on
> the append line from syslinux config add what is in the environment to
> the bootargs.
>
> This is necessary to allow distros to have a single extlinux/extlinux.conf
> file which will work on multiple boards, even if these boards have different
> consoles (e.g. ttyS0 vs ttyAMA0).

> diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c

I know you rejected this afterwards, but since I read the patch before 
the reply, a couple of comments for anyone who finds this code in the 
archived and wants to copy it:

> +	char console[30] = "";

> -	if (label->append)
> +	if (label->append) {
>   		len += strlen(label->append);
> +		/* If no console in append and $console is set, use it */
> +		if (!strstr(label->append, "console=") && getenv("console")) {

This would get a false positive match for the text fooconsole= in the 
existing command-line. It might be better to strtok() (or similar) the 
existing value, so it can guarantee to match only options that start 
with console= not that contain console=.

> +			sprintf(console, " console=%s", getenv("console"));

This should check for buffer overflows, e.g. use snprintf().