[U-Boot] [PATCH] distro_bootcmd: do not try to fetch unused bootfile for PXE

[Stephen Warren]

On 12/02/2015 04:15 PM, Stefan Brüns wrote:
> pxe get derives the pxelinux config file name from the bootfile name,
> but the bootfile itself is never used and might not even exist.
> Disable bootfile autoload to avoid the delay.

I wasn't CC'd on this and only accidentally noticed it, since it just 
happened to be the first email in this list folder this morning. It's 
good to CC people based on ./scripts/get_maintainer.pl's output.

> diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h

>   #define BOOTENV_DEV_PXE(devtypeu, devtypel, instance) \
>   	"bootcmd_pxe=" \
>   		BOOTENV_RUN_USB_INIT \
> -		"dhcp; " \
> +		"env exists autoload && setenv autoload_save ${autoload}; " \
> +			"setenv autoload no; dhcp; " \
> +		"env exists autoload_save && setenv autoload ${autoload_save}; " \

I think that last line should be unconditional; the previous statement 
unconditionally sets autoload to no, so we want to unconditionally 
restore the previous value of autoload, irrespective of whether it was 
set or not.

I'd expect:

setenv autoload_save $autoload
setenv autoload no
dhcp
setenv autoload $autoload_save
setenv autoload_save

(or a cmdline option to "dhcp" to force it to only acquire an IP address 
would be nice too).