[U-Boot] Unexpected saving of all environment variables during EFI boot

[Heinrich Schuchardt]

This was merged as
ad644e7c18238026fecc647f62584d87d2c5b0a3
efi_loader: efi variable support

> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index ec40f41bcb..c406ff82ff 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -8,6 +8,7 @@
>  
>  #include <common.h>
>  #include <efi_loader.h>
> +#include <environment.h>
>  #include <malloc.h>
>  #include <asm/global_data.h>
>  #include <libfdt_env.h>
> @@ -942,6 +943,11 @@ static efi_status_t EFIAPI efi_exit_boot_services(void *image_handle,
>  {
>  	EFI_ENTRY("%p, %ld", image_handle, map_key);
>  
> +#if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
> +	/* save any EFI variables that have been written: */
> +	env_save();

You save all changed variables and not specifically those bound to EFI.
This is completely unexpected behavior for the user and not covered by
the commit message.

Furthermore you call env_save even if no EFI variable has been touched
at all.

This leads to writing to flash on every boot via EFI. Depending on
technology this might ruin the flash after a few hundred reboots.

Please, revert this part of the change.

Best regards

Heinrich Schuchardt