[PATCH] env: Avoid using a leftover text-environment file

[Sean Anderson]

On 3/12/22 12:37 AM, Simon Glass wrote:
> If include/generated/environment.h exists (perhaps leftover from a build
> of another board) it is used, even if the board currently being built does
> not have a text environment.
> 
> This causes a build error. Fix it by emptying the file if it should not be
> there.
> 
> Fixes: https://source.denx.de/u-boot/u-boot/-/issues/9
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Reported-by: Sean Anderson <seanga2 at gmail.com>
> ---
> 
>   Makefile | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index 9ef34ca4b7f..2351d6dacd2 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1834,7 +1834,9 @@ ENV_FILE := $(if $(ENV_SOURCE_FILE),$(ENV_FILE_CFG),$(wildcard $(ENV_FILE_BOARD)
>   
>   # Run the environment text file through the preprocessor, but only if it is
>   # non-empty, to save time and possible build errors if something is wonky with
> -# the board
> +# the board.
> +# If there is no ENV_FILE, produce an empty output file, to prevent a previous
> +# build's file being used in the case of in-tree builds.
>   quiet_cmd_gen_envp = ENVP    $@
>         cmd_gen_envp = \
>   	if [ -s "$(ENV_FILE)" ]; then \
> @@ -1845,6 +1847,7 @@ quiet_cmd_gen_envp = ENVP    $@
>   			-I$(srctree)/arch/$(ARCH)/include \
>   			$< -o $@; \
>   	else \
> +		rm $@; \
>   		touch $@ ; \
>   	fi
>   include/generated/env.in: include/generated/env.txt FORCE
> 

Thanks!

Tested-by: Sean Anderson <seanga2 at gmail.com>